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Alesis ADAT HD24

Jan 01, 2017



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Page 1: Alesis ADAT HD24
Page 2: Alesis ADAT HD24

ContentsWelcome! .......................................................... 3About the ADAT HD24...................................... 3

Important features of your ADAT HD24 .... 3ADAT HD24 key features:.................................. 5

How to Use This Manual........................... 6

Important Safety Instructions................................... 7Instructions de Sécurité Importantes (French) ...... 8Beim Benutzen dieses Produktes beachten Siebitte die folgenden Sicherheitshinweise:(German) .......................................................... 9CE Declaration of Conformity........................... 10Instructions to the User (FCC Notice) ................ 10

Quick Start Guide.................................................. 11If you can't wait to get started:.......................... 11Front panel tour—left side................................ 14Front panel tour—right side ............................. 15

Locate/auto buttons ............................... 15Special features....................................... 15

About the Display............................................ 16Rear panel tour................................................ 17

Connections......................................................... 19Unpacking and Inspection................................ 19

Mounting on a Shelf or Non-RackEnclosure ............................................... 19

Installing in a Rack .......................................... 19Thermal Considerations in RackMounting............................................... 19

Power ............................................................. 20AC Power Hookup ................................. 20AC Grounding ....................................... 20

Analog inputs and outputs............................... 21From the console to the HD24's inputs:..... 22About Audio Cables ............................... 23Typical input jack hookups...................... 23

Sync In/Out .................................................... 24ADAT Optical Digital Inputs and Outputs ........ 25

About 16-bit and 20-bit signal transfers .... 25High sample rate operation ..................... 25

Footswitches ................................................... 29The LRC Remote.............................................. 29

Basic Recording and Playback ................................ 31About the hard drives ...................................... 31Songs.............................................................. 31

Making A Recording ........................................34Time Counter..........................................34Transport Buttons....................................35

Recording ........................................................35Sample Rate Selection..............................35Track Selection and Setting Levels ............36

The meters .......................................................37Peak hold modes .....................................37Setting the Recording Level......................38

Input Select......................................................39Digital Input ...........................................39Clock Source settings when recordingthe Digital Input......................................39Using All Input .......................................39

Input Monitor Controls.....................................40Auto Input..............................................40All Input.................................................40

Playback ..........................................................41Scanning.................................................41Scrubbing ...............................................41

Pitch Control....................................................42

Using Locate Points ...............................................43Locating ..........................................................43Special Locate Points ........................................43Other Locate Commands ..................................45Creating A Playback/Record Loop....................45Automated Recording ......................................47


Working with Drives ..............................................49Mounting and selecting a drive .........................49

How Drives Get Mounted........................50Dismounting drives.................................50

Adding additional drives..................................51Disk size and recording time....................51

Backing up your work ......................................54

Editing ................................................................55Editing Controls...............................................55Using the Edit Start and Edit End Points ............56Adjusting the Edit Start and Edit End Points ......57Using the Cut and Copy Commands..................58Using the Paste Command................................60Undo...............................................................62

The Edit Buffer and Levels of Undo..........62Track Slip ........................................................63More about editing...........................................64

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2 ADAT HD24 Reference Manual

High resolution operation ...................................... 6588.2/96 kHz sampling rates.............................. 65

The tradeoffs .......................................... 65Ensuring sample-rate compatibility.......... 65How ADAT Optical handles a 96 or88.2k signal ............................................ 66

Using the HD24 with an external High SampleRate-capable A/D or D/A converter................. 66The optional 96k Analog I/O boards................. 66

Synchronization and MIDI ..................................... 67Synchronization............................................... 67

MIDI Time Code..................................... 67SMPTE Time Code.................................. 67

MIDI............................................................... 68Using the HD24 with tape-based ADATs .......... 69

Synchronizing with ADAT...................... 69Using the ADAT HD24 with the BRC MasterRemote Control ............................................... 70

Matching start times for synchronization.. 70Compatibility issues ............................... 70

Using the HD24 with the M20........................... 72

Using Ethernet ..................................................... 73When you'd use Ethernet and the HD24............ 73

What you can do..................................... 73Limitations............................................. 73

Materials you will need.................................... 74Cables.................................................... 74Hub ....................................................... 74Interface card ......................................... 74Software................................................. 74

Setting the IP parameters of the ADAT HD24 .... 75About setting up your computer....................... 76

A word of caution................................... 76

Apple Macintosh configuration instructions.......77Connection .............................................77Setting up the AppleTalk, TCP/IP andRemote Access control panels...................77

Windows 95/98/ME PC configurationinstructions......................................................80

Verifying a PC's connection to theHD24......................................................83

Transferring files with Explorer.........................84Tips and tricks about Explorer..................85About using FTP download software........85

To upload files from the computer to theHD24...............................................................86More about IP addresses...................................86About the subnet mask .....................................87About the gateway address...............................87Connecting the HD24 directly to a cable orDSL modem.....................................................87To quit FTP server mode...................................88An Example Network .......................................89

Troubleshooting....................................................91Troubleshooting Index......................................91

Avoiding ground loop noise ....................93Line Conditioners and Protectors .............93

Care and Maintenance ......................................94Cleaning .................................................94Refer All Servicing to Alesis .....................94Obtaining Repair Service .........................95

Specifications.......................................................97Dimensional drawing .......................................98

Index ..................................................................99

Alesis Limited Warranty ....................................... 101

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Introduction/Safety Instructions

ADAT HD24 Reference Manual 3

Welcome!Thank you for making the Alesis ADAT HD24™ apart of your studio. Since 1984, we've beendesigning and building creative tools for the audiocommunity. We believe in our products, becausewe've heard the results that creative people like youhave achieved with them. One of Alesis' goals is tomake high-quality studio equipment available toeveryone, and this Reference Manual is an importantpart of that. After all, there's no point in makingequipment with all kinds of capabilities if no oneexplains how to use them. So, we try to write ourmanuals as carefully as we build our products.

The goal of this manual is to get you the informationyou need as quickly as possible, with a minimum ofhassle. We hope we've achieved that. If not, pleasedrop us an email and give us your suggestions onhow we could improve future editions of thismanual.

We hope your investment will bring you many yearsof creative enjoyment and help you achieve yourgoals.

Sincerely,The people of Alesis Studio Electronics

About the ADAT HD24Alesis, the company that revolutionizedmultitrack recording with the introduction ofthe ADAT, now offers the ADAT HD24 harddisk recorder. The HD24 writes to hard disk ina special way to provide 24 tracks of 24-bitaudio on low-cost IDE hard drives, and offersdrop-in compatibility with over 150,000 ADATsystems world wide. The ADAT HD24 shattersthe cost-per-track price barrier for professionalquality audio recording.

Important features of your ADATHD24

Uses affordable, hot-swappable harddrives as removable media:

To allow the use of affordable IDE hard drivesas removable recording media, on a cost andperformance par with tape, Alesis had toovercome limitations such as data fragmentationthat occurs in traditional hard disk recordingformats. In order to achieve this, Alesisengineered a new method of writing on harddrives called ADAT FST™, specifically designedfor music recording. Unlike the writing schemesemployed by computer-based systems, this newmethod keeps tracks of a given song in adjacentsectors of the hard disk, reducing the required"seek time" for the drive, providing a muchgreater level of stability in recording andplaying back data. Using ADAT FST, seek-to-play functions are virtually instantaneous, andthe data fragmentation that can cause hard diskcrashes is greatly diminished. As a result, verylow-cost, widely available, low-RPM IDE harddrives can be used with exceptional results. Forthe first time, at about $4 per gigabyte, the costof the hard disk storage medium is less than thatof ADAT tape. Entire 24-track projects can bestored on a single removable drive. Alesisengineered custom drive caddies and protectivestorage cases to establish today's affordable IDEdrives as the new exchange medium for musicrecording. The HD24 ships with two drivecaddies, one loaded with a 10-gigabyte harddrive which will yield approximately 45 minutesof 24-track recording time at 24-bit/48 kHz, andthe other ready for you to install your own drivein.

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Introduction/Safety Instructions

4 ADAT HD24 Reference Manual

Everything you need is built-in:

The HD24 comes complete with 24 channels ofanalog and digital inputs and outputs—there are nocards or extras to buy to get audio in or out of therecorder. Superb sonic performance was a base-lineobjective for Alesis. The HD24 provides 24 tracks ofhigh-resolution 24-bit uncompressed linearrecording at standard sample rates of 44.1kHz or 48kHz. It supports 12 tracks at sample rates of88.2kHz and 96kHz when slaved to external digitalproducts such as A/D, D/A converters, and aforthcoming 96 kHz option will allow high-samplerate analog I/O right from the back panel. Anexternal BNC word clock input is provided forslaving to external clock sources. The HD24 alsoprovides powerful editing capabilities with CUT,COPY, PASTE and multiple UNDO functions acrossany or all tracks simultaneously.

Connects easily to over 150,000 ADATsystems worldwide:

The rear panel of HD24 includes 24 channels ofADAT Optical inputs and outputs and ADAT SyncIN and OUT connectors to allow HD24 to sample-accurately synchronize with other ADATs, a BRCremote controller, and products from over 100manufacturers. When connected to a BRC, theHD24 emulates three traditional ADATs. Up to fiveADAT HD24 units can be synchronized to make upto 120-track systems, simply by chaining 9-pincables from the Sync Out of one HD24 to the Sync Inof another.

Provides multiple methods of filetransfer:

The HD24 allows you to move data to and fromthe recorder in THREE convenient ways:

• The hard drives used by the HD24 are soaffordable that drive caddies can be storedon the shelf just like tape, and instantly hot-plugged into the front panel when you wantto change projects. The ADAT FST driveformat establishes removable hard drives asthe most reliable, easiest-to-use multitrackmedia for pro applications. Two front-paneldrive bays allow quick retrieval and fastback up of projects. Drives are hot-swappable, and fast back-up (a few minutesfor an entire drive) is possible between twofront-panel drive bays.

• Industry-standard ADAT Optical I/Oallows transfer of up to 24 tracks of 24-bitaudio simultaneously in real-time usinginexpensive fiber-optic cables. The HD24can easily send digital audio to and fromdevices such as tape-based ADATs, digitalmixing consoles, and computer cards orinterfaces.

• A rear-panel Ethernet port allows the HD24to be connected as a stand-alone FTP serverwith its own IP address that can be accessedfrom a computer network, even over theInternet! Songs appear as folders on anyWeb browser, containing individual .WAVor AIFF files for each track. You candownload and upload files from any HD24connected to a network. Files can then beprocessed using computer-based editingapplications and moved back to the HD24.

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Introduction/Safety Instructions

ADAT HD24 Reference Manual 5

ADAT HD24 key features:1. 24 Track simultaneous recording at 44.1/48 kHz

(12 tracks @ 88.2/96 kHz)2 . Storage media: Standard IDE hard drive

(minimum 5,400 RPM)3. Recording time per each 10 gigabytes @ 48kHz:

45 minutes x 24 tracks; @ 96kHz: 45 minutes x 12tracks

4 . Number of drive bays: Two front-panel, hot-swappable

5. Recording Modes: 44.1/48 kHz

24 track, 16 track, 8 track, 4 track, 2 track 88.2/96 kHz

12 track, 8 track, 6 track, 2 track6. Resolution: 24 bit linear PCM encoding7 . Internal clock Fs: 44.1kHz, 48kHz, 88.2kHz,

96kHz; External clock; Varispeed -16%/+6%@48kHz

8. A/D converters: Twenty-four channels of 24 bit,128x oversampling (standard)

9. D/A converters: Twenty-four channels of 24-bit128x oversampling (standard)

1 0 . OPTION: 96 kHz-capable A/D/D/A board(Dealer-installed circuit board, replaces standardA/D/D/A circuit board)

11. Analog I/O spec: +4 dBu nominal level (for –15dBFS digital level) on balanced 1/4" TRSconnectors x 48 (standard)

12. Digital I/O: 24 channels (3 each, 8 channels) -ADAT Optical format IN, 24 channels ADAT

Optical OUT, on standard fiber-optic 1mmToslink-style connectors

13. Synchronization: ADAT Sync. Up to fiveHD24 units can be synchronized for up to120 sample-accurate tracks. Control andslaving is possible from any ADAT Syncdevice.

1 4 . Remote control: Ships with ADAT LRCremote control. HD24 can be also becontrolled via ADAT Sync port, or MIDIMachine Control. Optional full-functionremote control (available soon).

1 5 . Editing: Cut, Copy, Paste, Move, Insertacross any or all tracks. Multiple levels ofundo

16. MIDI: IN, OUT. MIDI Time Code transmit;MMC and SYSEX transmit and receive

1 7 . Software update method: Via MIDI orEthernet

18. Data transfer via Ethernet FTP, 10Base-T,using standard Cat 5 cable (RJ-45 connector)


Frequency response: 22Hz - 22kHz ±0.5 dBTotal Harmonic Distortion: <.003%Signal To Noise: > 103dB, A-weightedDynamic Range: 144dB, digital IN to digitalOUT; > 103 dB analog IN to analog OUT A-weighted



Recordingtime permedia unit

Qty. req'dfor 24 track,45 min.project

Per trackminute

Per 24-trackminute


ADAT Tape(unformatted)

$15.00 ea. 42 min. x 8tracks x 20 bit)

3 tapes 4 cents $1.00 $45.00

Standard IDEHard Drive5400 rpm

$99.00/ 30GBAverage

135 min. x 24track, 24 bit

1/3 of a drive(10 GB)

3 cents 73 cents $33.00

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6 ADAT HD24 Reference Manual

How to Use This ManualThis manual is divided into the following sectionsdescribing the various functions and applications forthe ADAT HD24. While it's a good idea to readthrough the entire manual once carefully, thosehaving general knowledge about studio equipmentshould use the table of contents to look up specificfunctions.

Chapter 1: Quick Start. If you're alreadyexperienced with recording, this will get you startedusing the ADAT HD24 right away. It's a short guideto the essential elements of hooking it up and usingit for the first time. A brief tour of the front andback panels also directs you to the chapters focusedon individual features.

Chapter 2: Connection and Chapter 3:Basic Recording and Playback give detailedinstructions for connecting the ADAT HD24 to avariety of typical audio systems and guides youthrough your first recordings step-by-step. Themiddle chapters focus on features you don't have toknow about, but that make recording and mixingeasier: Using Locate Points, Editing.

Chapters 6-9 cover deep backgroundinformation that will help you use your ADATHD24 to its greatest capability by synchronizing it toother ADATs, communicating with sequencersusing MIDI, connecting it to a computer usingEthernet, and adding 88.2/96 kHz sampling.

Near the end of the manual are troubleshootingtips, specifications, and an Index tohelp you find what you're looking for.

Helpful tips and advice are highlighted in a shadedbox like this.

In text, the names of specific controls or connectorson the hardware of the HD24 are printed in a specialfont, i.e., the RECORD button.

When something important appears in themanual, an icon (like the one on the left) willappear in the left margin. This symbolindicates that this information is vital whenoperating the ADAT HD24.

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ADAT HD24 Reference Manual 7

Important Safety InstructionsSafety symbols used in thisproduct

This symbol alerts the user that there areimportant operating and maintenance instructionsin the literature accompanying this unit.

This symbol warns the user of uninsulatedvoltage within the unit that can cause dangerouselectric shocks.

This symbol warns the user that outputconnectors contain voltages that can causedangerous electrical shock.

Please follow these precautionswhen using this product:

1. Read these instructions.

2. Keep these instructions.

3. Heed all warnings.

4. Follow all instructions.

5. Do not use this apparatus near water.

6. Clean only with a damp cloth. Do not spray anyliquid cleaner onto the faceplate, as this may damagethe front panel controls or cause a dangerouscondition.

7. Install in accordance with the manufacturer'sinstructions.

8. Do not install near any heat sources such as radiators,heat registers, stoves, or other apparatus (includingamplifiers) that produce heat.

9. Do not defeat the safety purpose of the polarizedor grounding-type plug. A polarized plug has two

blades with one wider than the other. A grounding-type plug has two blades and a third groundingprong. The wide blade or the third prong areprovided for your safety. When the provided plugdoes not fit into your outlet, consult an electrician forreplacement of the obsolete outlet.

10. Protect the power cord from being walked on orpinched, particularly at plugs, conveniencereceptacles, and the point where they exit from theapparatus.

11. Use only attachments or accessories specified by themanufacturer.

12. Use only with a cart, stand,bracket, or table designed for use withprofessional audio or music equipment.In any installation, make sure that injuryor damage will not result from cablespulling on the apparatus and its

mounting. If a cart is used, use caution when movingthe cart/apparatus combination to avoid injury fromtip-over.

13. Unplug this apparatus during lightning storms orwhen unused for long periods of time.

14. Refer all servicing to qualified service personnel.Servicing is required when the apparatus has beendamaged in any way, such as when the power-supply cord or plug is damaged, liquid has beenspilled or objects have fallen into the apparatus, theapparatus has been exposed to rain or moisture, doesnot operate normally, or has been dropped.

15. This unit produces heat when operated normally.Operate in a well-ventilated area with at least sixinches of clearance from peripheral equipment.

16. This product, in combination with an amplifier andheadphones or speakers, may be capable ofproducing sound levels that could cause permanenthearing loss. Do not operate for a long period of timeat a high volume level or at a level that isuncomfortable. If you experience any hearing loss orringing in the ears, you should consult anaudiologist.

17. Do not expose the apparatus to dripping orsplashing. Do not place objects filled with liquids(flower vases, softdrink cans, coffee cups) on theapparatus.

18. WARNING: To reduce the risk of fire or electricshock, do not expose this apparatus to rain ormoisture.

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Introduction/Safety Instructions

8 ADAT HD24 Reference Manual

Instructions de Sécurité Importantes (French)

Symboles utilisés dans ce produit

Ce symbole alèrte l’utilisateur qu’il existedes instructions de fonctionnement et demaintenance dans la documentation jointe avec ceproduit.

Ce symbole avertit l’utilisateur de laprésence d’une tension non isolée à l’intérieur del’appareil pouvant engendrer des chocs électriques.

Ce symbole prévient l'utilisateur de laprésence de tensions sur les raccordements desorties, représentant un risque d'électrocution.

Veuillez suivre ces précautions lors del’utilisation de l’appareil:

1. Lisez ces instructions.

2. Gardez ces instructions.

3. Tenez compte de tous les avertissements.

4. Suivez toutes les instructions.

5. N’utilisez pas cet allareil à proximité de l’eau.

6. Ne nettoyez qu’avec un chiffon humide. Il estpotentiellement dangereux d'utiliser despulvérisateurs ou nettoyants liquides sur cetappareil.

7. Installez selon les recommandations duconstructeur.

8. Ne pas installer à proximilé de sources dechaleur comme radiateurs, cuisinière ou autreappareils (don’t les amplificateurs) produisantde la chaleur.

9. Ne pas enlever la prise de terre du cordonsecteur. Une prise murale avec terre deuxbroches et une troisièrme reliée à la terre. Cette

dernière est présente pour votre sécurité. Sile cordon secteur ne rentre pas dans la prisede courant, demandez à un électricienqualifié de remplacer la prise.

10. Evitez de marcher sur le cordon secteur oude le pincer, en particulier au niveau de laprise, et aux endroits où il sor de l’appareil.

11. N’utilisez que des accessoires spécifiés par leconstructeur.

12. N’utilisez qu’avec un stand,ou table conçus pourl ’ u t i l i s a t i o n d ’ a u d i o

professionnel ou instruments de musique.Dans toute installation, veillez de ne rienendommager à cause de câbles qui tirent surdes appareils et leur support.

13. Débranchez l’appareil lors d’un orage oulorsqu’il n’est pas utilisé pendantlongtemps.

14. Faites réparer par un personnelqualifié. Une réparation est nécessairelorsque l’appareil a été endommagé dequelque sorte que ce soit, par exemplelosrque le cordon secteur ou la prise sontendommagés, si du liquide a coulé ou desobjets se sont introduits dans l’appareil, sicelui-ci a été exposé à la pluie ou àl’humidité, ne fonctionne pas normalementou est tombé.

15. Puisque son fonctionement normale génèrede la chaleur, placez cet appareil au moins15cm. des équipments péripheriques etassurez que l’emplacement permet lacirculation de l’air.

16. Ce produit, utilisé avec un amplificateur etun casque ou des enceintes, est capable deproduite des niveaux sonores pouvantengendrer une perte permanente de l’ouïe.Ne l’utilisez pas pendant longtemps à unniveau sonore élevé ou à un niveau nonconfortable. Si vous remarquez une perte del’ouïe ou un bourdonnement dans lesoreilles, consultez un spécialiste.

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Introduction/Safety Instructions

ADAT HD24 Reference Manual 9

Beim Benutzen dieses Produktes beachten Sie bitte die folgendenSicherheitshinweise: (German)

1. Lesen Sie die Hinweise.

2. Halten Sie sich an die Anleitung.

3. Beachten Sie alle Warnungen.

4. Beachten Sie alle Hinweise.

5. Bringen Sie das Gerät nie mit Wasser inBerührung.

6. Verwenden Sie zur Reinigung nur einweiches Tuch. Verwenden Sie keineflüssigen Reinigungsmittel. Dies kanngefährliche Folgen haben.

7. Halten Sie sich beim Aufbau des Gerätes andie Angaben des Herstellers.

8. Stellen Sie das Gerät nich in der Nähe vonHeizkörpern, Heizungsklappen oderanderen Wärmequellen (einschließlichVerstärkern) auf.

9. Verlegen Sie das Netzkabel des Gerätesniemals so, daß man darüber stolpern kannoder daß es gequetscht wird.

10. Benutzen Sie nur das vom Herstellerempfohlene Zubehör.

11. Verwenden Sie ausschließlich Wagen,Ständer, oder Tische, die speziellfür professionelle Audio- undMusikinstrumente geeignet sind.Achten Sie immer darauf, daß diejeweiligen Geräte sicher installiert

sind, um Schäden und Verletzungen zuvermeiden. Wenn Sie einen Rollwagenbenutzen, achten Sie darauf, das diesernicht umkippt, um Verletzungenauszuschließen.

12. Ziehen Sie während eines Gewittersoder wenn Sie das Gerät über einenlängeren Zeitraum nicht benutzen denNetzstecher aus der Steckdose.

13. Die Wartung sollte nur durchqualifiziertes Fachpersonal erfolgen.Die Wartung wird notwendig, wenn dasGerät beschädigt wurde oder aber dasStromkabel oder der Stecker,Gegenstände oder Flüssigkeit in dasGerät gelangt sind, das Gerät demRegen oder Feuchtigkeit ausgesetzt warund deshalb nicht mehr normal arbeitetoder heruntergefallen ist.

14. Dieses Gerät produziert auch imnormalen Betrieb Wärme. Achten Siedeshalb auf ausreichende Lüftung mitmindestens 15 cm Abstand von anderenGeräten.

15. Dieses Produkt kann in Verbindung miteinem Verstärker und Kopfhörern oderLautsprechern Lautstärkepegelerzeugen, die anhaltende Gehörschädenverursachen. Betreiben Sie es nicht überlängere Zeit mit hoher Lautstärke odereinem Pegel, der Ihnen unangenehm is.Wenn Sie ein Nachlassen des Gehörsoder ein Klingeln in den Ohrenfeststellen, sollten Sie einen Ohrenarztaufsuchen.

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10 ADAT HD24 Reference Manual

CE Declaration of Conformity

Manufacturer’s Name: Alesis CorporationManufacturer’s Address: 12509 Beatrice Street

Los Angeles, CA 90066USA

declares, that the product:

Product Name: ADAT HD24Model Type: Digital audio recording device

conforms to the Standards for Safety and EMC for this product listed on the Internet site:

Instructions to the User (FCC Notice)

This equipment has been tested and found tocomply with the limits for a class B digital device,pursuant to Part 15 of the FCC Rules. These limitsare designed to provide reasonable protectionagainst harmful interference in a residentialinstallation. This equipment generates, uses, andcan radiate radio frequency energy and, if notinstalled and used in accordance with theinstructions, may cause harmful interference toradio communications. However, there is noguarantee that interference will not occur in aparticular installation. If this equipment does causeharmful interference to radio or television reception,which can be determined by turning the equipmentoff and on, the user is encouraged to try and correctthe interference by one or more of the followingmeasures:

• Reorient or relocate the receiving antenna.

• Increase the separation between the equipmentand receiver.

• Connect the equipment into an outlet on acircuit different from that to which the receiveris connected.

• Consult the dealer or an experienced radio/TVtechnician for help.

This equipment has been verified to comply withthe limits for a class B computing device, pursuantto FCC Rules. In order to maintain compliance withFCC regulations, shielded cables must be used withthis equipment. Operation with non-approvedequipment or unshielded cables is likely to result ininterference to radio and TV reception. The user iscautioned that changes and modifications made tothe equipment without the approval ofmanufacturer could void the user’s authority tooperate this equipment.

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chapter 1

ADAT HD24 Reference Manual 11

Quick Start GuideIf you can't wait to get started:

If you're experienced with multitrack recording, thischapter is a "shorthand" guide for those who wantto start using the HD24 right away. The basichookup and operation of the Alesis ADAT HD24™is similar to that of previous ADATs in mostrespects. If you have questions about any of thefeatures, don’t worry – later chapters will unveil themysteries of the HD24's unique and special features.

If you're new to multitrack recording, startwith the more detailed instructions forhookup and operation starting in the nextchapter.

Step 1: Hook it up to a mixer

1. Pull the ADAT HD24 out of the package.

2. Make sure the POWER switch on the back of theHD24 is OFF, and plug it into a grounded ACpower source with the supplied power cable.

2. Connect the outputs of a mixer to the INPUTS onthe back of the ADAT HD24.

3. Connect the OUTPUTS of the ADAT HD24 to theLINE IN or TAPE IN jacks of the mixingconsole.

If you're using a digital mixer:

Instead of steps 2 and 3 above, use opticalcables to connect the three sets of ADAT OPTICALDIGITAL inputs and the three sets of outputs tothe mixer.

You'll need six long optical cables for this.

4. Turn the POWER switch on the back of the HD24ON.

Once you have done this, in the future you shouldpress the POWER switch on the front of theHD24 to turn it on or off.

For more information on connecting the

HD24, see chapter 2: Connections.

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quick start guide • chapter 1

12 ADAT HD24 Reference Manual

Step 2: Get the drive ready

Mount and select the hard driveWhen you first turn on the power, the HD24 willautomatically mount the last drive that was selectedin the system. (Mounting means that the systemrecognizes the disk, has powered it up, and cancommunicate with it.) If you have two hard drivesinstalled, only one will be mounted. Since this is thefirst time you are powering up the unit, the HD24will mount the drive that you installed in Drive bay1.

• If there were no drives inserted, they will bemounted automatically when you pushthem in.

• If you have two drives inserted, one drivemay be selected for use at a time, eventhough both are mounted. A selected driveis the one that will be used for recording orplayback. The drive that was most recentlyselected will be selected automatically atpower-up. (See the icons next to the HDFREE SPACE display to find out which oneis selected.

In any case, there has to be at least one valid driveinserted and mounted, with its green DRIVE LED litbefore you can proceed.

NOTE: Never pull a drive caddy out unless the DRIVELED is OFF! Dismount the drive first bypressing its DRIVE button and then the YES() button.

To select a disk if it's not mounted:

1. Press the DRIVE button of the disk you want touse.

The display will read:

Selecting HD2

with a progress bar underneath for a few seconds,until the drive has mounted.

Initialize or select the song2. On a new, empty drive the display will read:

No songs on disk

(press NEW SONG)

Or, if the drive already has songs on it, it willshow the last song used.

S0 1 : "Song Name "

00:03:55:10 24t

Press YES () (under the display) if you want tochange to a different song.

If the HD24 is in a menu or mode you don'tunderstand, STOP. Look through the manualto learn more about the situation beforeproceeding.

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chapter 1 • quick start guide

ADAT HD24 Reference Manual 13

Step 3: Try a test recording

Now we’re ready to try some basic recording. Inthis exercise, we’ll simply record some audio into anew song, then play it back to hear the results.

1. First, press the NEW SONG button on the topright corner of the unit. The display shouldlook like this:

Create New Song?

(Press Y /N)

2. Press the YES () button. The display shouldthen look like this:

SampleRate?48. 0 k

(Press New Song)

3. Press the YES () or NO () buttons to select asample rate–either 44.1kHz, 48kHz, 88.2kHz, or96kHz.

If you aren’t sure which one to use, choose 48kHz.

4. When you’ve made a choice, press the NEWSONG button. The display will prompt you forthe number of tracks:

# of Tracks? 2 4

(Press New Song)

5. Choose the number of tracks you want in yoursession. Press the NO () button a few times tochoose 8 tracks for this example, then press NEWSONG.

The reason that you would choose a smaller numberof tracks is that larger sessions use much more diskspace.

The display will now show the default “SongName” and you are ready to record.

6. The next step is to choose an input format.

• If you are using an analog mixer, make sure that“Input” is set to “Analog” on the bottom leftcorner of the display. If it isn’t, press the INPUTSELECT button.

• If you are using a digital mixer, press the INPUTSELECT button so that the “Input” indicator inthe bottom left corner of the display reads“Digital”. Then press the CLOCK SOURCE buttonuntil the “Clock Source” indicator in the displayreads “Optical”. If you hear ticks and popswhen you arm a track, see page 25, “ADATOptical Digital Inputs and Outputs”.

7. Next, arm a track. Press the numbered buttonsbelow the meters of the tracks you want to arm,also known as Track Record Enable buttons.

The red Record light will flash under the tracksselected for record, and the blue Input light will alsoturn on.

8. Send some signal to the HD24. This can be fromthe Tape or Group outputs of your mixer, oryou can simply use a line level source (CDplayer, drum machine, etc.). Plug this sourceinto the Input of the track you are recording to(1,2, etc.)

9. Set the level of the source so that the loudestpeaks do not light the red “Clip” lights on theHD24’s meters, but light the meter segmentsjust below that point.

10. Press PLAY and RECORD. Begin playing thesource.

11. Press STOP once you’ve recorded a few bars.

12. Press the REW or LOCATE 0 button to go to thebeginning of the song, then press PLAY to hearwhat you recorded.

You can now arm other tracks and record morelayers to your song. When you’re finished, give thesong a name by pressing the NAME button and usingthe oval-shaped cursor keys (YES (), N O (), <and >).

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Front panel tour—left sideMetersEach track has its own 10-segment, peak-reading meter.When it turns yellow, you have 6 dB or less ofheadroom left. At the top, the red CLIP warns you ofthe onset of clipping.

If a track's meter is surrounded by a lit rectangle, thattrack is currently selected for editing. See page55.

REC INDICATORS: These indicate when a track is"armed" for recording (flashing) or in record (solid),as controlled by TRACK BUTTONS 1-24.

INPUT INDICATORS: These indicate when a trackis monitoring its input (indicator ON), ascontrolled by the AUTO INPUT, ALL INPUT buttonsin combination with whether the track is armed.

See page 40 for details.

DRIVE 1, DRIVE 2: Use these buttons to select orunmount (power down) a drive. The LED beneathit indicates the state ofthe drive:

• If the LED isoff, the drive isunmounted (orempty) andmay beremoved.

• LED green: thedrive ismounted.

• LED red: thedrive is currentlybeing accessed forrecording orplayback.

To see which drive isselected, look at the iconsnext to the HD Free Spacedisplay. See page 49.

POWER (SOFT): Once the"hard" POWER switch on therear panel is ON, push this toturn the unit on and off.

TRACK BUTTONS 1-24: these are most oftenused to arm a track for recording, but theyare also used to select tracks for editing.

TRACK EDIT: Hold this while pressing a TRACKbutton to select a track for editing.

PEAK MODE: This sets how themeter will display peaks:continuously holding them untilPEAK CLEAR is pressed, holdingpeaks on the meter for a fewmoments, or not hold them at all.

For more about the meters and

level setting, see Chapter 3: BasicRecording and Playback.


The ADATHD24 recordson removable,affordable IDEhard drives. Itcomes sup-plied with a 10-gigabyte drivein the DRIVE 1slot, whichgives you 45minutes of 24-track recordingtime (1080 totaltrack minutes).The DRIVE 2

slot comes with an empty caddy, which you can fillwith an IDE drive of any size, from almost anymanufacturer (see your Alesis dealer for details).Additional drive caddies are available from yourAlesis dealer, so you can instantly swap outprojects, just as conveniently as tape.

Never pull a drive caddy out unless its LED isoff! Doing so could physically damage thedrive or corrupt data on it.

For more information about drive caddies, see Chapter 5:Working with Drives.

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Front panel tour—right sideEditing buttonsThe EDIT START and EDIT ENDbuttons define a region of atrack (or tracks, as determinedby the TRACK EDIT button) thatcan be selected for editing.Press CUT to remove the region(leaving silence on the track),and COPY to copy it withoutremoving it. PASTE pastes theaudio that was cut or copiedstarting at the EDIT IN point,overwriting data on theselected track(s). If you decidethe edit you made was amistake, press UNDO to go backto the way it was.

You can UNDO onlyedit operations.Recordings andoverdubs can't beundone.

S e e Chapter 6: Editing fordetailed information on editingin the ADAT HD24.

Locate/auto buttonsallow you to instantly accessseven different locations inthe current Song: LOCATE 0returns to the zero point,while LOCATE 1-6 instantlylocate to those points storedin memory. SET LOCATE recordsthe current location in the nextlocate point (above that shownin the display). When AUTOPLAY is on, the HD24 willautomatically start playingwhen a locate point is reached.The LOCATE key sends the HD24to the location currently shownin the bottom of the display.See Chapter 4: Using Locate Points fordetails.

Display buttonsThese buttons relate to the iconsat the bottom of the display.INPUT SELECT toggles betweenanalog or digital input. CLOCKSOURCE selects whether theHD24's sample rate will be setby the INTernal clock, theWORD IN jack on the backpanel, or the OPTICAL input.

If the clock is internal, SAMPLERATE allows you to select thesample rate (44.1, 48, 88.2, or 96kHz). LOCATE SELECT, alongwith the cursor keys below,allows you to select which ofthe current Song's 24 locationswill be accessed when youpress the LOCATE key.

CURSOR buttons: YES (), NO(), < and > control whateveris currently shown the middleof the display—selecting songs,naming them, answeringquestions. See the next page forexamples of how these areused.

STOP, PLAY, RECORD work asthey do on any recorder. TapREW or FFWD to jump 5 secondsin either direction, or hold themto continue scanning.

Song buttonsPress SONG SEL to select any of64 song locations to record orplay back. NEW SONGinitializes a blank song,allowing you to choose howmany tracks it will have, etc.Use DEL SONG to delete a songfrom the hard drive, and NAMEto name a song or locate point.

Special featuresAs long as the clock sourcedisplay shows INT, PITCH allowsyou to speed up or slow downthe playback or recordingspeed.

UTILITY is used for importanthousekeeping tasks such as

setting the ISP address,etc.

TRACK SLIP is an editingfunction that allows youto time-delay or advanceany tracks up to 170 ms.

Press MIDI when you wantto see the menus thatcontrol MIDI Time Codegeneration, MIDIMachine Control input,etc.See Chapter 8: Synchronizationand MIDI.

The AUTO RETURN andAUTO RECORD buttons allowyou to set up a "loop" so youcan record a section over andover, until you get it right.REHEARSE allows you to hear apunch in as if it were beingrecorded, without erasing it.Details are covered in Chapter 4:Using Locate Points.

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About the Display

Time countershows the current location (fromthe Song Start point, zero in ABStime) in hours, minutes, seconds,and frames.

Auto Iconslight whenever theAUTO RECORD, AUTOPLAY, AUTO RETURN, orREHEARSE functions areengaged.

HD FREE SPACE indicatorshows how muchrecording time is availableon the selected disk at thecurrent track width andsample rate. The smallyellow indicator to the leftshows whether Drive 1 orDrive 2 is selected (it's 2 inthis display)

The alphanumericdisplay:This does different things,depending on what'sgoing on at the time. Inthis example, it shows thecurrent Song (number 01,titled "HD24".) On thesecond line, it's showingthe length of the song: sixminutes, 13 seconds, and20 frames. It's alsoshowing that this song has24 tracks. As shown, thecursor (underline) isbeneath the Song number,

Status iconsshow the current settingscontrolled by the INPUT,CLOCK SOURCE AND SAMPLERATE (switches underneaththe display) and theMONITOR icon shows thestatus of ALL INPUT ANDAUTO INPUT (switches tothe left of the display).

Locate pointdisplay:Each Song has its ownset of 24 Locate points.This shows you whichone the HD24 willaccess if the LOCATEbutton is pressed. Italso shows you if thepoint is being used asthe START, END, punchIN or OUT point of oneof the AUTO features.See Chapter 4: Using LocatePoints for details.

Tracksavailable(Not in alldisplays.) Showshow many tracksare available in thecurrent Song—inthis case, all 24.Tracks take updisk space even ifthey're notrecorded, so don'tinitialize a songwith more thanyou need.See page 30 forinformation onsetting the trackcount of a song.

Write-protectstatus(Not in alldisplays.) An iconof a lockedpadlock willappear in songsthat have beenprotected fromchanges. Anunlocked padlockicon will appear insongs that areNOT write-protected.

and pressing the YES () button would change toSong 02. If a screen is asking a question (like,Delete Song?), you press YES () or NO () asyou wish.

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Rear panel tour

AC connectorThis is where a standard IECdetachable power cord plugsin.

POWER switch (hard)Normally, you'll leave thisswitch on, controlling powerfrom the front panel switch.

Always turn off the unit using thefront panel POWERswitch first. The "soft"power-off procedureparks the drive heads,so they may be removedsafely.

EthernetConnect this jack to a computerto transfer audio to anyworkstation. Each Song willappear as a folder containingeach track as a separate .WAVor .AIFF file. Since the HD24uses FTP, you can even connectthis jack to a cable modem totransfer files over the Internet.See Chapter 9: Ethernet.

Analog I/OThese INPUT and OUTPUT jacksmay be connected to balancedor unbalanced mixers, sincethey're 3-conductor balanced1/4” phone jacks (also calledTRS for “tip-ring-sleeve”). See

Chapter 2: Connections.

Word clock inputConnect the word clock outputof a digital mixer or masterclock source to this jack, toensure that everything in thestudio samples at exactly thesame time, avoiding ticks andclicks.

LRC and PUNCHConnect the LRC remotecontrol (supplied) to the LRCjack, and any momentaryfootswitch (optional) to thePUNCH jack for hands-freerecording.

MIDIMIDI IN allows the HD24 tofollow MMC commands from asequencer, and MIDI OUT cantransmit MMC and MTC (MIDITime Code). See Chapter 8:Synchronization and MIDI.

ADAT Optical (DigitalI/O)Each of these connectors carries8 channels of digital audioinformation (or, 4 channels atthe 88.2/96 kHz sampling rate).See Chapter 2: Connections.

ADAT SyncConnect a remote control (suchas the BRC™) to the SYNC INjack. Or, connect a 9-pin cablefrom the SYNC OUT jack ofanother ADAT unit here toexpand a system to as many as120 simultaneous tracks. See

Chapter 8: Synchronization and MIDIand Chapter 2: Connections.

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ConnectionsUnpacking and Inspection

Your ADAT HD24 was packed carefully at thefactory. The shipping carton was designed toprotect the unit during shipping. Please retain thiscontainer in the highly unlikely event that you needto return the HD24 for servicing.

The shipping carton should contain the followingitems:

• ADAT HD24 with the same serial number asshown on shipping carton

• Power cable

• LRC remote control unit

• This reference manual

• Two drive caddies, one with an installed harddrive

• Stick-on rubber feet for table top installation

• Alesis warranty card

It is important to register your purchase; ifyou have not already filled out yourwarranty card and mailed it back to Alesis,please take the time to do so now.

Mounting on a Shelf or Non-RackEnclosureTo mount the HD24 on a shelf or other flat surface,Alesis recommends attaching the included stick-onfeet to the deck’s bottom to avoid scratching theshelf’s surface.

Please observe the general comments on thermalconsiderat ions given under “ThermalConsiderations in Rack Mounting” no matter whereor how the deck is mounted.

Installing in a RackThe ADAT HD24 may be simply set on a table, orinstalled in a standard 19” audio equipment rack.The rack ears are integral to the unit.

The ADAT HD24 has a small cooling fan thatvents towards the rear of the unit. Make surethis outlet is not blocked. Make sure the rackitself has ventilation of the rear area.

Thermal Considerations in RackMountingThe HD24 can be mounted in an equipment rack(taking up 3 rack spaces) or placed on a table orshelf. When you install it, keep in mind that heat isthe major enemy of electronic equipment. Pleaseobserve the following:

• The HD24 is designed to perform properly overa range of ambient temperatures from 10° C to+40° C (50° F to 104° F), in up to 80% non-condensing humidity. These are not absolutelimits, but Alesis cannot guarantee that theHD24 will meet its published specs or remainreliable if operated outside of these ranges.

• Always allow adequate ventilation behind theHD24. Do not seal any enclosure that holds theHD24. It is not necessary to leave an emptyrack space above or below the HD24 unless itruns hot enough to affect equipment above orbelow it. If your environment is unusuallywarm and not air conditioned, space betweenunits will help the units run cooler.

• Do not attach the stick-on feet to the bottom ofthe HD24 if it will be rack-mounted.

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Make sure you read the initial ImportantSafety Instructions chapter at the front of thismanual.

AC Power HookupWith the POWER switch on the REARPANEL of the ADAT HD24 turned OFF, plugthe female end of the power cord into the HD24’sPOWER INPUT socket and the male (plug) end into agood quality, noise-free AC power source of theproper rating.

It’s good practice to not turn on the HD24 until allother audio cables are hooked up as well.Make sure your amplifier or poweredspeakers are switched off when turning theHD24 on or off to avoid damage.

The ADAT HD24 works with any standard linevoltage from 90 to 240 volts and comes with adetachable AC line cord suitable for the country towhich the unit is shipped.

AC GroundingThe line cable is an IEC-spec AC power cabledesigned to be connected to a grounded 3-pinoutlet, with the third, round pin connected toground. Do not substitute any other type of ACcord; IEC-spec cables of various lengths may bepurchased from electronics stores or your Alesisdealer.

The ground connection is an important safetyfeature designed to keep the chassis of electronicdevices such as the ADAT HD24 at groundpotential. Unfortunately, the presence of a third pindoes not always indicate that an outlet is properlygrounded. You may use an AC line tester todetermine this. If the outlet is not grounded, consultwith a licensed electrician. When AC currents aresuspected of being highly unstable in VAC and Hz,a professional power conditioner should be used.

Do not operate any electrical equipment withungrounded outlets. Plugging the ADATHD24 into an ungrounded outlet, or “lifting”the unit off ground with a three-to-two wireadapter, can create a hazardous condition.Alesis cannot be responsible for problemscaused by using the ADAT HD24 or anyassociated equipment with improper ACwiring.

To use the ADAT in another country:

The ADAT HD24 has what's called a "switchingpower supply". That means it works with any ACvoltage from 90 to 250 volts, 50 to 60 Hz. Thiseliminates the need for transformers or voltageswitches when you travel from country to country.Your HD24 was supplied with the correct powercord for your country or local area. If you plan totravel with it to another country, obtain an IEC-specAC power cable compatible with the outlets used inthe other country and use it in place of the suppliedcable. The following alternative power cords areapproved for use with it:

• For 90-120 VAC 50/60 Hz operation in the US,Canada and/or Japan, use Alesis UL/CSApower cord #7-41-0001.

• For 240 VAC 50 Hz operation in England, useAlesis Power cord #7-41-0004.

• For 220 VAC 50 Hz operation in Europe andScandinavia, use Alesis EU power cord #7-41-0002.

• For 240 VAC 50 Hz operation in Australia, useAlesis AS power cord #7-41-0003.

Do you hear an AC hum in your system?For detailed tips on how to get rid of "groundloops" that cause hum, see page 92.

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Analog inputs and outputs

When connecting audio cables and/orturning power on and off, make sure that alldevices in your system are turned off and thevolume controls are turned down.

Outputs from the HD24 to a mixingconsole:

Balanced outputsThe ADAT HD24's 24 analog OUTPUTS should beconnected to the balanced line inputs or "tapeinputs" of a recording console.

The line inputs of most modern consoles aredesigned to accommodate a three-conductor TRS(tip-ring-sleeve) 1/4" phone jack, (non-militarytype) as shown below:








Unbalanced Line Input








Balanced Line Input




This is the same connector used in the ADAT HD24.Obtain 24 channels of 3-conductor TRS 1/4"-to-1/4"cable, and connect the outputs of the HD24 to theinputs of the console.

Unbalanced outputsYou may use two-conductor 1/4" phone cables ifyour mixer doesn't have balanced inputs. In somecases, the mixer may have "RCA/Phono" inputs. Inthis case, obtain adapter cables.

Tip: Label or color-code cables whereverpossible. With 48 different I/O connections,you don't want to guess. "Snakes" (multipaircables) are a good idea; you can get them in8, 16, and 24-channel versions. Some havenumbers written on the wire so you can tellone cable from another.

Others use different colors of wire. If so, use anacronym to keep the colors in order (like "RoyG. Biv" stands for red-orange-yellow-green-blue-indigo-violet in the order 1-2-3-4-5-6-7-8). Use the same color order for the inputsand the outputs.

If you're using snakes, make sure you label (with amarking pen on tape, or with a commerciallabel machine) which are the inputs, which arethe outputs, and which tracks they go to.Someday, you'll be glad you took the time.

If the mixer has XLR line inputs:

First of all, make sure that the XLR inputs are for“tape returns”. XLR inputs on most consoles areintended for microphone-level signals, not line-levelinputs. However, if the line or tape inputs of theconsole use XLR connectors, you'll need to obtain anXLR-to-TRS (1/4") cable assembly. These are wiredas shown below:

Pin 2 (+)

Pin 3 (-)

Pin 1 (Ground)

Sleeve (Ground) Tip (+)

Ring (-)

Don't use line transformers: Many XLR-to-1/4" adapters sold at electronics stores are NOT adapters,but transformers (and very low quality transformers at that). Don't use these on the output of the ADATHD24—they're unnecessary and generally sound awful because they don't have the headroom to handle theADAT HD24's output. Get a hard-wired adapter or cable from your professional audio dealer, or make oneyourself from components.

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From the console to theHD24's inputs:What's INPUT NORMALLING?Most affordable analog consoles don'thave 24 outputs. Even those with 24 or32 tape inputs usually have only eightbusses or group outputs. Luckily, theHD24 is designed so it can still be usedwith eight, four, or even two-busconsoles, thanks to a feature calledinput normalling that allows signalfrom the console plugged into onetrack to appear at others. For example,if you have an 8-bus console, simplyconnect from the bus/group outputs tothe first 8 tracks of the ADAT HD24.Signal from the first input will appearat tracks 1, 9, and 17 without forcingyou to repatch any cables, once you setthe INPUT NORMALLING feature.

To connect from the groupouts of a mixer:

You can choose between five different Input Modes:2-Input Mode, 4-Input Mode, 8-Input Mode, 12-Input Mode, and 24-Input Mode. These can providefive different analog audio input hookup options:

• 2 Bus Mixer: Connect the mixer’s two busoutputs to the HD24’s INPUTS [1] and [2]. Select2-Input Mode on the HD24 by holding downthe INPUT SELECT button until the display reads:

Select Audio

Input Tracks

Then press either Track Select buttons [1] or [2];notice that the INPUT LEDs for tracks 1 and 2remain lit until you release the INPUT SELECTbutton.

• 4 Bus Mixer: Connect the mixer’s four busoutputs to the HD24’s INPUTS [1] through [4].Select 4-Input Mode by holding down the INPUTSELECT button until you’re prompted to selectthe tracks; press either Track Select buttons [3]or [4]. The INPUT LEDs for tracks 1 through 4remain lit until you release the INPUT SELECTbutton.

• 8 Bus Mixer/Direct Outputs: Connectthe mixer’s eight bus outputs (or 8 directoutputs) to the HD24’s INPUTS [1] through [8].Select 8-Input Mode by holding the INPUTSELECT button and pressing any Track Selectbutton from [5] - [8]. The INPUT LEDs for tracks1 through 8 remain lit until you release theINPUT SELECT button.

• 12 Bus Mixer: You’ve got the drill by now,right? When the display reads “SelectAudio Input Tracks”, press a TrackSelect button between 9 and 12, and the lowerinputs will “normal” to the higher tracks (1 to 1and 13, 2 to 2 and 14, etc.)

• 24 Bus Mixer (or Direct Outs): Samedeal—press INPUT SELECT and press a track 13 orabove to have the “normal” setup with eachtrack “hearing” its own separate input.

In the first four modes, the HD24 internallyconnects the inputs to the higher tracks (forexample, Input 1 goes to tracks 1, 9 and 17 in 8-Input mode).

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About Audio CablesThe connections between the ADAT HD24 and yourstudio are your music’s lifeline, so use only highquality cables. These should be low-capacitanceshielded cables with a stranded (not solid) internalconductor and a low-resistance shield. Althoughquality cables cost more, they do make a difference.

Route cables to the HD24 correctly byobserving the following precautions:

• Do not bundle audio cables with AC powercords.

• Avoid running audio cables near sources ofelectromagnetic interference such astransformers, monitors, computers, etc.

• Do not place cables where they can be steppedon. Stepping on a cable may not causeimmediate damage, but it can compress theinsulation between the center conductor andshield (degrading performance) or reduce thecable’s reliability.

• Avoid twisting the cable or having it makesharp, right angle turns.

• Never unplug a cable by pulling on the wireitself. Always unplug by firmly grasping thebody of the plug and pulling directly outward.

And most importantly, keep connectorsclean. Every few months, unplug them andwipe off oxidation with a clean cloth soaked inalcohol or contact cleaner. Insert the plugs inthe jacks a few times, to clean the internal jackcontacts. Although Alesis does not endorseany specific product, certain chemicals, whenapplied to electrical connectors, are claimed toimprove the electrical contact betweenconnectors. Avoid oily products that actuallyattract more dirt.

The ADAT HD24 is wired according to the modernstandard of “Pin 2 (tip) = Hot”. Some olderequipment was wired with Pin 3 hot; check tomake sure correct polarity is maintainedthroughout your system.

Typical input jack hookupsThe inputs of a multitrack recorder are typicallyhooked up in one of three ways:

• From the console’s "direct outs"(sometimes labeled "tape outs".This patches one channel of the mixer directlyto one track of the recorder, bypassing mostmixer circuitry. This is preferred when thesignals going to tape require none of the mixer’sfeatures (effects, grouping, routing, etc.).

• From the mixer's "bus" or "group"outputs. You can use the mixer for grouping,premixing, effects, etc. This puts more circuitrybetween the sources and the HD24, althoughsince most routing can be done at the mixer,you’ll seldom need to do any repatching.

• From a combination of directoutputs and bus outputs. Somesituations require a combination of the twoapproaches, especially if you're recording a lotof tracks at once and your mixer has only 8group outputs:


Here's a typical arrangement that might be used ona live tracking session, cutting basics for a full bandplus two "guide vocals":

Mic Mixer out TrackKick Direct out 1Snare " 2Snare bottom " 3Hi-hat " 4Tom 1 Group 1-2 5-6 (pan left)Tom 2 " 5-6 (left-center)Tom 3 " 5-6 (right-center)Tom 4 " 5-6 (pan right)Overhead left Direct out 7Overhead right Direct out 8Bass " 9Guitar " 10Piano Group 3-4 11-12 (stereo)Digital synth " "Analog synth " "Vocal 1 Direct out 13Vocal 2 " 14

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Even a 4-bus mixer could be used to record these 14tracks.

Sync In/OutThe two DB 9 connectors on the back panel markedSYNC IN and SYNC OUT are used for synchronizingtwo or more HD24s together, or a combination ofHD24s and other ADATs, or a computerworkstation using the ADAT/EDIT card or similardevice. Up to five HD24s can be linked, making a120-track system. This requires a male-to-male, 9-pin D connector cable for each additional machinein the chain.

Use only Alesis-approved Sync cables, available invarious lengths from your dealer. Impropercables (such as those used forcomputers) may not functioncorrectly.

In such a system, you are basically treating allconnected machines as though they were a largemultitrack unit. The first ADAT in the chain iscalled the “master”, and all other connected unitsare referred to as “slaves”. However, each slave canalso be used independently when the mastermachine is stopped.

The Sync In and Out connections can also be usedfor synchronizing to SMPTE Time Code. SeeChapter 8 for more information.

To synchronize multiple HD24sand/or ADATs:

1. Locate the SYNC IN and SYNC OUT connectors.

2. Connect one end of a male-to-male, 9-pinconnector cable to the master’s SYNC OUT jack.

3. Connect the other end of the cable to the firstslave’s SYNC IN jack.

4. For additional slaves, connect one end of amale-to-male, 9-pin D connector cable to thefirst slave’s SYNC OUT jack, and the other end tothe second slave’s SYNC IN jack. Its SYNC OUTjack then connects to the third slave’s SYNC INjack, and so on.

The moment the SYNC connection is made, theslave machine(s) will automatically switch toexternal clock and follow transport commands fromthe master (unless taken offline by dismounting alldrives, or ejecting tapes). For moreinformation about using multiple HD24sand/or ADATs, refer to chapter 8.

The illustration below depicts an ADAT HD24being used as the master machine to another HD24so they can be synchronized together, making a 48-track recorder.

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ADAT Optical Digital Inputs andOutputs

Each of the digital inputs and outputs of the ADATHD24 carries eight tracks or channels (up to 48 kHz)on a single fiber optic cable in the industry-standardADAT Optical format. To cover the 24 tracks of theHD24, there are three sets of inputs and three sets ofoutputs. Connect these outputs if you want to:

• copy audio between ADATs within thedigital domain

• connect to a digital mixing console

• transfer audio to and from a computerworkstation with ADAT Optical ports

• receive digital signals from many Alesiskeyboards and effect devices

Digital copying requires three fiber optic cables foreach HD24 in the system (or any other ADAT-compatible product). Additional cables are availablefrom your dealer in various lengths up to 16 feet.When connecting a digital mixer, you'll need six cables per HD24 in the system. Digital audioconnections can be made while power is on or off.Note: To bounce tracks within a single HD24, it isnot necessary to connect the optical network.

About 16-bit and 20-bit signaltransfersAll data on the ADAT Optical cable has alwaysbeen in a 24-bit word length; in earlier 16-bitADATs the eight least significant bits are filled withzeroes, in 20-bit ADATs the last four bits are zeroes.If 24-bit data is sent to a 20-bit machine, the four“extra” bits are simply ignored, much as fractions ofa penny don't matter when you actually pay yourbill at the gas station. ADAT Type II machines(such as the M20, XT20, and LX20) can receive a full20-bit transfer via the optical cables (if the tapes inthose machines were formatted in 20-bit mode).The ADAT/EDIT system can receive a full 24-bittransfer, as can many other computer workstations.

If you have a digital mixer, you may need toupgrade its software or hardware to receive orgenerate true 24-bit signals via the ADATOptical interface.

To transfer audio from the HD24 tonon-24-bit systems you have twooptions:

1. Transmit at 24 bit, and the receiving unit willignore the bits it can't read, essentially cuttingthem off. This option provides the lowest noisewhen tracks are going to be processed andmixed.

2. Connect the machines via analog inputs andoutputs. This will effectively dither the 24-bitsignal of the HD24 to whatever the receiver isusing. While a digital transfer is theoreticallybest, today’s converters are of such high qualitythat the difference is usually not audible.

High sample rate operationAt the 88.2 and 96 kHz sample rates, the ADATOptical format becomes essentially a 4-channelinterface. See Chapter 7, "High ResolutionOperation".

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To connect the digital inputs andoutputs

1. Locate the DIGITAL IN and DIGITAL OUTconnectors for Tracks 1-8.

Remove the connectors’ plugs (if present) and storefor later use.

2. Remove the clear, plastic tube covering eachend of the optical cable (if present). Connectone end of the fiber optic cable into the DIGITALOUT 1-8 jack of the HD24.

The cable is non-polarized, so either end can beinserted into the optical output.

3. Connect the other end of the fiber optic cable tothe ADAT Optical™ input for the first eighttracks of the receiver (mixer, computerinterface, or ADAT).

Tip: if the machines are on, the cable from the sourcemachine will show a red light at the end.

4. Repeat steps 2 and 3 for the DIGITAL OUT 9-16and DIGITAL OUT 17-24 jacks.

At this point, you should be able to PLAY a song onthe HD24 and hear it (or see the meters move) on theother unit.

5. Now, connect the outputs of the other device tothe DIGITAL IN 1-8, DIGITAL IN 9-16 and DIGITALOUT 17-24 of the HD24.

Only eight outputs on the other device?In some cases, such as an 8-bus digital mixerwithout direct outputs, you may not need toconnect to the DIGITAL IN 9-16 and DIGITAL IN17-24 of the HD24. The HD24 canelectronically "patch" a digital input from itsfirst eight inputs to higher tracks if needed.See page 22.

The illustration below shows an HD24 connected toan 8-bus digital mixer. The mixer’s ADAT Opticaloutputs are connected to the HD24 Digital Inputsand the HD24’s Digital Outputs are connected tothe mixer’s ADAT Optical Inputs.

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Copying between ADATs

If you combine an ADAT HD24 with severalADATs in a system and aren't using a digital mixer,you may connect them directly so you can copy theHD24 to tape and the tapes to the HD24.

To digitally copy between an HD24 and tape-basedADATs, simply connect the DIGITAL OUTS of theHD24 machine to the DIGITAL INS of three differentADATs, and then the inputs to the outputs, asshown below. Connect the SYNC OUTS so theHD24 is last in the chain.

ADAT Optical hookups between two HD24s aren’tusually necessary—it’s faster to simply swaphard drives and make copies in a singlemachine.

Don’t loop the opticals: Unlike tape-basedADATs, the HD24 is not designed to beconnected in a digital loop; there is no “digitalthrough” mode where one HD24 will simply“pass along” the digital signal at its input. Thedigital output of each HD24 simply representswhatever is on that particular machine.

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Connecting to a computer interfacecard

This illustration shows an HD24 connected to anADAT-compatible computer interface card. Thecard’s ADAT outputs are connected to the HD24Digital Inputs and the HD24’s Digital Outputs areconnected to the card’s ADAT Inputs. In thisparticular case the ADAT SYNC is connected so thatthe card (computer) is the master or controller of theADAT HD24. Check with the manual for yourcomputer interface for complete instructions.

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FootswitchesThe HD24 provides two footswitch connectors onits rear panel using 1/4" mono (T/S) jacks. One,labeled LRC, allows locate and play commands whenused with a standard footswitch, or more elaboratecontrol when used with the LRC Remote control;the other, labeled PUNCH, is for punch in/outcontrol.

The two footswitch jack functions are designed tobe used with any momentary single-pole/single-throw footswitch (either normally open or normallyclosed*). These should be plugged in prior topower-up so that the HD24 can configure itself forthe type of footswitch being used.

When using a normally open footswitch, thefootswitch can be plugged in withoutrestarting the HD24 (powering down andpowering up). However, if using a normallyclosed footswitch, the HD24 should berestarted after plugging it in. Don’t step onthe footswitch while the HD24 is beingpowered on, or the switch will operate“backwards”.

The LRC RemoteYou can connect the compact “LRC” HD24 remotecontrol unit to the LRC jack only to provide remoteaccess of transport functions. Using the punch jackfor an LRC does not work on the HD24. An ADATLRC can also be used, but double-check the labelingof the buttons as these have changed for the HD24.

The Punch In/Out footswitch and HD24 Remoteboth work in conjunction with the Rehearseand Auto Record features. See Chapter 4,"Using Locate Points".

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Basic Recording and PlaybackAbout the hard drives

There are no "internal" hard drives in the ADAT-HD24; the drive bays on the front panel housedrives up to 2000 GB each which can be removedand/or replaced while the machine is powered up,as long as the LED indicator for thedrive is OFF. Because the HD24 usesinexpensive, off-the-shelf IDE-format hard drivesinstead of more expensive SCSI drives as itsrecording medium, it's practical to use a drive aspermanent storage for audio instead ofdownloading to tape or optical disc.

For this chapter, we'll assume that you're using thedrive supplied with the unit, and the caddy isinserted in the left slot (DRIVE 1). This drive willautomatically mount when the unit is powered on.

If you see a message in the display such as"No Disk Drive Selected", see Chapter 5,“Working with Drives” before proceeding.

SongsSongs are the basic structures the ADAT HD24uses to record tracks. Up to 64 Songs may bestored on a single drive. You must select anexisting Song, or start a new Song, before you canrecord or play back.

• Each Song is defined from the beginning ashaving a certain number of tracks (2, 6, 8, 16,or 24). More tracks use up more disk space.

• Each Song has its own unique locate points:the zero point, 20 namable locate points, andfour special points (punch in, punch out, editin, and edit out).

• A Song can be up to 23 hours long, subject tothe limit of available disk space on a singledrive.

• Each Song can be named (up to 10 characterslong).

• Each Song is initialized at a certain samplerate (although it may be played back at adifferent one).

This is what the display looks like in Song Selectmode:

S0 1 :"Song Name "

00:05:00:00 24t

The display above shows the song number (Song01), the song name (“Song Name”), the song'slength (5 minutes), the write protect status of thesong (indicated by the "locked" or "unlocked"icons), and the track "width" of the song (24tracks), as chosen during the NEW SONGcreation process. The song number, song name,write protect status, and song name fields areeditable, while the song length and song trackwidth is not.

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To select a Song:

1. On power-up, the ADAT HD24 will mount adrive and automatically select the last song youwere using. If the display looks something likethis:

S0 1 :"Song Name "

00:00:00:00 24t

it is already in Song Select mode. If not, pressSONG SEL.

2. Press the YES () or N O () buttons to scrollthrough the available Songs. A maximum of 64songs per disk are possible; however, onlySongs that have already been created using theNEW SONG button will be displayed.

If the transport is playing when a new song isselected, the transport will stop before changingsongs.

If there are no songs on the disk (if all Songs aredeleted through the use of the DEL SONG button),the following message will be displayed when theSONG SEL button is pressed:

No Songs On Disk

(Press NEW SONG)

To initialize a new Song:

1. Press the NEW SONG button once to bring upthe display shown below:

Create New Song?

(Press Y /N)

If the transport is playing, it will continueplaying until the YES () button is pressed. If theNO () button is pressed, the screen will revert towhatever it was previously displaying.

2. Press the YES () button to create a new songentry on the currently-selected drive. Thefollowing message will be displayed:

SampleRate?48. 0 k

(Press New Song)

3. Press the YES () or NO () button to scrollthrough the possible sample rates: 44.1k,48.0k 88.2k, and 96.0kHz.

Note that if 88.2 or 96.0k are selected, the Songwill be forced to default to optical input if there isno 96kHz-compatible ADC and DAC PCB

installed. See Chapter 9: High Sample Rate Operation.

4. Press NEW SONG to choose the displayedsample rate. This will bring up the trackconfiguration screen:

# of Tracks? 2 4

(Press New Song)

5. Press YES () or NO () to scroll through thepossible configurations: 2, 6, 8, 16, and 24.Once the appropriate track width has beenchosen, pressing NEW SONG once more willcomplete the song creation, and will bring upthe Song Select screen, as shown below:

SXX:"Song Name "

00:00:00:00 XXt

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To name a Song:

With up to 64 possible Songs on a drive, it's a goodidea to give each one a unique name that will helpyou find the tracks you need. Names may be up to10 characters long. It takes only a few seconds.

1. Press the NAME button.

This will cause the cursor to enter the Name field,underneath the first character of the name.

2. Press YES () or NO () to scroll through analphanumeric set of characters. Press both keyssimultaneously to clear the character.

3. When you have the character you want, pressthe > (CURSOR RIGHT) key to move the cursorto the next character.

4. When you're done, press NAME again to exit theSong Name field and store the new name.

About Song sample rates: Many peoplemixing down through a digital mixer willmultitrack at 44.1 kHz so they can digitallymix for CD release without having to gothrough sample-rate conversion at mastering.Those with analog mixers typically use 48kHz (standard professional rate). If you haveequipment capable of it and are willing todeal with the tradeoffs (see page 65), youmay use 88.2 kHz (which is still compatiblewith CDs) or 96 kHz.

To delete a Song:

You may delete Songs to free up disk space formore recording. A Song of a certain length takesup space even for tracks that were never recordedon.

1. Press DEL SONG. This will bring up thedisplay shown below:

Delete Song 01?

(Press Y/N)

2. Pressing YES () will cause the followingscreen to be displayed:

Are You Sure?

(Press Y/N)

If the transport is playing, it will continueplaying until the YES button is pressed. If the NObutton is pressed, the screen will revert towhatever it was previously displaying.

3. Pressing the YES () button will stop thetransport if playing, delete the song entryfrom the hard disk, and will free up the diskspace previously allocated to that song.

Deleting a Song is permanent, like erasinga tape. It can't be recovered by pressingthe UNDO button.

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Making A RecordingRecording on the HD24 is similar to recording on amultitrack tape machine, if you think of each Songbeing like its own small tape. The process involvesselecting a song (see previous tutorial), putting oneor more tracks into record-ready, adjusting recordlevels on your mixer, setting the input monitormode, locating to the start time and engagingrecord.

Time CounterBefore recording, you should familiarize yourselfwith the transport buttons, and the TIME counteron the top line of the display. The current positionin the Song is displayed as hours:minutes:seconds:frames. A “frame “ is 1/30th of a second.

00H 15M 48S 21 F

The counter typically uses 00:00:00:00 as thebeginning of each song. Pressing the LOCATE 0button will instantly locate the HD24 to the startpoint of the currently selected Song.

There is no “leader” or preroll in the HD24; there isno way to “rewind” past the Locate 0 or “samplezero” point (although, of course, you may record asmuch silence as you wish in a Song before themusic starts).

Absolute and Relative TimesFor synchronization with tape-based ADATs orMIDI sequencers, you can redefine the time stampused for the Locate 0 point. This doesn’t changeanything except the time counter display and thetime code reference used at the SYNC IN, SYNCOUT and (if MTC is enabled) MIDI OUT jacks.

For example, if you reset Locate 0 to 00:04:00:00, thestart of the current Song will correspond to thefour-minute time on an ADAT tape. All locationpoints in the current song will remain the same, butwill have four minutes added to them. See page 44for information on how to edit the Locate 0 point.

Unlike tape-based ADATs, where each song isrecorded with a different place on the tape,the ADAT HD24 treats every Song as itsown miniature “tape” starting at zero andending at the current song length. If youpress PLAY on Song 01, it doesn’t continueonto Song 02 or 03, etc.

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Transport ButtonsDuring recording and playback, the followingtransport buttons are used frequently. Get familiarwith them by using them while watching the TIMEcounter.

LOCATE Sends the HD24 to the currently-selected locate point shown inthe lower-right side of the display.

REW Press once to jump back five seconds; hold to scroll backwards(rewind), hold with STOP to scrub backwards.

FFWD Press once to jump ahead five seconds; hold to scroll forward (fastforward), hold with STOP to scrub forward.

STOP Stops transport and disables recording.Press with REW or FFWD to hear the audio at slow speed (“scrub”).Hold for 2 seconds to unthread tape-based slave ADATs.

PLAY Starts playback. Initiates recording when pressed with RECORD.Stops recording when in record mode while continuing to play.

RECORD Press with PLAY to initiate recording.

RecordingRecording takes place only on tracks that are inrecord-ready. When you start recording, the[RECORD] LED lights, and the [REC] LEDs for thosetracks in record-ready will stop flashing andremain lit.

The ADAT HD24 doesn't allow "punching in"directly on the track buttons; tracks mustalready be in record-ready mode beforeRECORD is pressed.

Sample Rate SelectionIf you want to override the sample rate the Songwas formatted with, you may change the samplerate you will be using (44.1 kHz, 48 kHz, or88.2/96 kHz with the optional 96 kHz A/D/D/Aconverter board). This sample rate will apply toonly the current Song. When you select a song, itwill always default to the sample rate it wascreated with, even if you change it later.

Normally, you record and play back at thesame rate…otherwise the pitch and tempowill be different.

To change the playback sample rate, press theSAMPLE RATE button. Each time SAMPLE RATE ispressed, the HD24 will cycle between 48K and44.1K, and 88.2K and 96K if the optional upgradehas been installed. Note: For more informationabout the 96 kHz A/D/D/A board, see page 66.

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Track Selection and Setting LevelsYou’ll find the RECORD ENABLE buttons ([1]–[24])for all twenty-four tracks on the left side of thefront panel, beneath the display.

A track is considered:

• “safe” when its REC LED is off

• in “record-ready” when its REC LED isflashing, and

• “in record” when its REC LED is lit solid.

To RECORD-enable a track:

1. Choose a track to record on, and press thetrack’s associated RECORD ENABLE button1–24.

The selected track’s [REC] LED will flash toindicate it is in record-ready.

2. Send an audio signal to the track(s) you haveplaced into record-ready.

3. Adjust the levels on your mixer so that the“average” level is at -15 dB on the peak metersof the ADAT HD24 and the loudest sectionnever goes beyond 0 dB.

Digital audio recording is different from analogrecording, and therefore requires a different methodwhen setting levels. For more information, seeSetting the Recording Level on page 38.

4. To take a track out of record-ready (safe), pressits associated RECORD ENABLE button again.The selected track’s REC LED will turn off toindicate it is safe.

To make a recording:

1. Hold PLAY, and then press RECORD.

Both the PLAY and RECORD LEDs will light toindicate you are recording. Any enabled tracks’[REC] LEDs will light solid.

2. Press STOP to end recording, and define thelength of the song (if this is the first take inthe song).

The RECORD LED turns off and the track LEDswill flash again; the STOP LED lights.. The songlength counter (shown whenever the display is inSong Select mode) will be updated to show thelength of the song, at the end of recording.

Note: until a Song has data recorded in it, theFF and REW keys have no effect.

After the first tracks have been recordedyou can:

• use the PLAY key to punch out, instead ofSTOP

• use the LOCATE, REW or FFWD buttons to locateto the desired time before recording

• scrub to a precise point to start recordingusing the STOP, REW and FFWD keys

The TIME counter will indicate the currentlocation point while the transport is in motion.

Note: When recording for the first time, makesure the Auto Input function is off. Whenrecording over previous material (also known aspunching), turn the Auto Input function on. Usethe AUTO INPUT button to turn Auto Input on andoff. The AUTO INPUT icon will light in the displaywhen Auto Input is on.

Note: Make sure to consult the next section,“Setting the Recording Level”.

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The metersEach of the tracks has its own 10-segment LCDmeter, with levels ranging from CLIP (0 dBFS) to–60 dB. Levels within 6 dB (1 bit) of clipping areshown in yellow. The standard nominal level forADAT, -15 dBFS, is two segments below that colorchange. (The "-15" label is shown in red; this levelwill usually equal "0 VU" on an analog mixerconnected to the input.)

Peak hold modesSince the peak level is the crucial issue in digitalrecording, the meters are designed to hold thehighest peak for a period of time, if you wish, usingthe buttons to the right of the meter. The ballisticsof the meters are controlled by the three Peak HoldModes and the Peak Clear button:

Continuous Peak HoldThis mode keeps the loudest signal sent to theoutputs displayed in the meter indefinitely. If alouder signal occurs, the previous value will bereplaced by this new value.

• To clear all of the peaks, press the PEAK CLEARbutton.

This mode is useful during recording when youwant to make sure that the recording levels havenever clipped, without constantly staring at themeters. You can glance at the meters periodically,then reduce the gain on the channels which are toohigh.

Momentary Peak HoldThis mode keeps the loudest signal sent to theoutputs displayed in the meter for one second. Ifa louder signal occurs, the previous value will bereplaced by this new value.

This is the default peak mode. Since the peaklevels are the most important value to monitorwhile recording, Momentary Peak hold allowsyou to concentrate on the peak values withoutkeeping them frozen on the screen.

No Peak HoldThis mode constantly updates the loudest signalbeing sent to the outputs. This mode tracks thecurrent audio level exactly from moment tomoment.

This mode is useful for seeing the actual moment-to-moment dynamics of the audio, but can makeit hard to see very short overloads that canhappen with instruments with a wide dynamicrange.

Peak ClearThe PEAK CLEAR button instantly resets the heldpeak values on the Meter Display.

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To change the peak hold mode:

The PEAK MODE button is designed to allow theuser to change the way that signal peaks aredisplayed in the Level Meter Display. Pressing thePEAK MODE button once brings up one of thefollowing displays (depending upon the currentstate of the peak metering):


Peak Hold


Peak Hold


Peak Hold

These messages indicate the current Peak Modestate. Pressing the PEAK MODE button again whileone of these messages are displayed will togglethrough the three modes; if the peak mode buttonis not pressed within a time-out period (about twoseconds), the display will revert to its previousstate and the Peak Mode will not be changed.

Setting the Recording LevelSetting the correct recording levels is crucial tomaking any recording sound its best. On anydigital recorder, the best resolution is foundwhen the maximum recording level of each trackfalls just below the “Clip” point. However, sincethe HD24 is a 24-bit recorder, you don’t need topush levels quite so hard to avoid noise anddistortion as you did in the past.

To set the correct recording level:

1. Select a channel to record to. This is usuallydictated by which mixer channel or group isfeeding the HD24.

See page 22 for tips on connecting the HD24 toyour mixer.

2. Send the signal from that mixer channel tothe HD24.

3. Press the Record Enable button for thechannel you are recording to. (1, 2, etc.)

The Record light will flash below the meter of thattrack.

4. Have the performer play the loudest sectionof the song you’re about to record. Adjustthe gain controls of your mixer (trim,channel, and master) until the loudest notesfall just below the Clip indicator on theHD24’s meter.

You may want to set the gain controlconservatively – most performers will play louderfor the actual take than the rehearsal.

For more information about setting gain controls,consult your mixer’s reference manual.

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Input SelectA single INPUT SELECT button (just below thedisplay) selects what source will be recorded: theANALOG or DIGITAL input. The currently selectedinput source is indicated in the lower left corner ofthe display.

When INPUT SELECT is set to ANALOG, the HD24looks to the 1/4” analog inputs on the rear panelfor its inputs. When INPUT SELECT is set to DIGITAL,the HD24 gets its input from the ADAT OpticalDigital Inputs.

Input Normalling (internal patching)While the INPUT SELECT button is being held, thechannel record and input status indicators nolonger indicate the current record or input status,and the REC icons turn off. As long as the button isbeing held, the track INPUT LEDs are used toindicate the Input Normalling status.

There are five different Input Normalling modes: 2-input, 4-input, 8-input, 12-input, and 24-input.Input Normalling works the same in both analogand digital input modes. For more informationabout setting Input Normalling modes, see page 22.

In 2-input mode, inputs 3-24 aredisconnected and cannot be recorded orheard. In 4-input mode, inputs 5-24 aresimilarly disconnected. To use all inputs, 24-input mode must be selected.

Digital InputTo record from the digital input, press the INPUTSELECT button until DIGITAL lights up under theINPUT icon in the display. The digital input can beused to record from any ADAT-compatible opticalsignal. All twenty-four channels will be receivedvia the fiber optic connections (see Digital In/Out inChapter 3) and the analog inputs will be ignored.

If you don’t get any input to a track, or get adifferent input than you expect, check the inputnormalling feature described above by holding theINPUT SELECT button.

Clock Source settings whenrecording the Digital InputIt’s important to set the correct CLOCK SOURCEwhen using Digital Input:

• When digitally recording from a sourcewhose input is set to Internal, set the HD24’sClock Source to Optical.

• If you’re using a master clock source for alldigital components of your studio, set theClock Source to Word. Connect a BNC cablebetween the Word Clock (48kHz) output ofthe master clock and the WORD IN jack of theHD24.

• If the HD24 has its ADAT Sync Inputconnected to another ADAT’s Sync Output oris controlled by a BRC, the Clock Sourcemode will automatically be set to ADAT.

If the Clock Source button is pressed and there isno valid digital input, the Clock Source icon willflash, indicating lack of a clock signal, and theclock will default to INTERNAL.

Using All InputThe ALL INPUT button allows the user to quicklyhear what is coming into the ADCs (or digitalinputs), despite the state of the track recordenable buttons.

Pressing the ALL INPUT button will cause it totoggle between On and Off states. When On, allanalog or digital outputs that are active for agiven song (6 in a 6-channel song, 24 in a 24-channel song, etc.) will always receive audio fromeither the Analog or Digital inputs, and the Inputsegments of the Level Meter Display light for all24 channels. When Off, the DACs derive theiraudio either from the Hard Disk, or from theAnalog or Digital inputs, or are muted,depending upon the state of the record enablesand the state of the transport. In addition, theInput segments of the Level Meter Display areextinguished when All Input is Off.

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Input Monitor ControlsThere are two Input Monitor controls: AUTO INPUTand ALL INPUT.

Auto InputThis feature determines what you will hear fromthe HD24’s output jacks when a track is record-enabled (REC LED flashing): the track, or the inputsource. The AUTO INPUT button toggles the AutoInput Monitor on and off.

At the bottom of the display, AUTO will light inyellow under the MONITOR icon.

When a track is monitoring its input signal, itsINPUT LED (the blue indicator under the meter) willbe lit.

• When Auto Input Monitor is off , all record-enabled tracks will monitor the input signaland all other tracks will monitor the playbacksignal.

• When the Auto Input Monitor is on (AUTOicon is lit), you'll hear the playback of thetrack right until the moment of punch-in,when it will switch to the input signal. You’llhear the input to record-enabled tracksduring record, stop, rewind or fast fwd, butnot in play.

The reason for having these two options is toaccommodate different stages of the recordingprocess. Leaving the Auto Input Monitor off isthe “normal” option and is what you would usewhen first recording tracks. When performingpunch-ins and overdubs, you will probably wantto turn the Auto Input Monitor on so that you canhear what was recorded on tape for a given trackright up to the point you want to punch in. Assoon as the HD24 punches into record mode, therecorded signal is replaced by the input signal soyou can hear what’s being recorded. After youpunch-out, the monitor reverts to playback.

Typically, Auto Input should be on when theRehearse feature is used (see page 48).

All InputWhen the ALL INPUT button is on (ALL icon underthe MONITOR icon is lit), the Auto Input Monitorsetting is overridden so that all tracks monitortheir input signals regardless of their recordenable status. All of the song’s tracks INPUT LEDswill be lit. When All Input Monitor is off (ALLicon is off ), the Auto Input Monitor settingdetermines track monitoring.

The following table indicates the status of tracksthat are record-enabled and tracks that are safe,depending on the status of the AUTO INPUT andALL INPUT buttons:

No monitor AUTO INPUT mode ALL INPUT modeTransport modeSafe Enabled Safe Enabled Safe Enabled

Stop/Pause/Rew/FFwd Playback Input Playback Input Input InputPLAY " " " Playback " "RECORD " " " Input " "

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PlaybackThere are several ways to quickly play back yourrecording. You’ll use the transport buttons first.

To play back a recording:

Press REW to locate back to the position you’relooking for, or use one of the Locate keys to goto a particular position.

The REW LED will light and the TIME counter willjump backward by five seconds. You can hold downthe REW button to continue moving through thesong.

Press PLAY.

The PLAY LED will light to indicate play mode hasbeen engaged.

Press STOP to stop playback.

The PLAY LED will turn off and the STOP LED willlight.

ScanningWhen you are trying to locate a particular sectionof a recording, it is often helpful to scan or skipthrough a song while hearing “chunks” of therecording. By listening to the audio, you canquickly find the section you are looking for.

To scan backward:

Press PLAY.

The PLAY LED will light.

While the HD24 is playing, tap the REW button.

The song will skip backwards five seconds each timeyou press REW and then continue playing.

To scan forward:

Press PLAY.

The PLAY LED will light.

While the HD24 is playing, tap the FFWD button.

The song will skip ahead five seconds each time youpress FFWD and then continue playing.

ScrubbingAnother useful function in the HD24 is scrubbingaudio. This is especially useful when trying tolocate the exact start of a note while editing, forexample.

If any tracks are selected for editing (see Chapter6), only these tracks will scrub. If no tracks areselected for editing, all tracks in the session willscrub.

The speed of scrubbing will change the longeryou hold the keys—it starts at a very slow crawl,then advances to several times play speed.

To scrub backward:

Press and hold STOP and press REW.

The PLAY and REW LEDs will light. Audio willbe heard at a very slow speed, increasing thelonger you hold it.

Release both buttons to resume normal operation.

Both the PLAY and REW LEDs will turn off, andthe STOP LED will turn on.

To scrub forward:

Press and hold STOP and press FFWD.

The PLAY and FFWD LEDs will light.

Release both buttons to resume normal operation.

Both the PLAY and FFWD LEDs will turn off, andthe STOP LED will turn on.

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Pitch ControlThe Pitch function controls the recording speed,and thus the pitch of the audio recorded on disk,whenever the CLOCK SOURCE is set to Internal.The HD24’s Pitch control has a range of -300 to+100 cents when using a sample rate of 48kHz or96kHz, and a range of -200 to +200 cents whenusing 44.1kHz or 88.2kHz.

Use the PITCH button to control the amount of pitchchange.

To set the Pitch amount:

1. Press the PITCH button. The display will read:

Pitch:+00 0 cents


2. Press YES () or NO () to change the pitch.

After holding for more than two seconds, the Pitchamount will start either increasing or decreasingmore rapidly, depending on which button ispressed.

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Using Locate PointsLocating

Up to 24 time positions can be stored in each Songfor easy recall. These are called Locate Points, andcan be stored either “on the fly” while the transportis engaged, or when the transport is stopped. Eachof the 64 Songs has its own unique Locate Pointsplus its own "zero" start point, for a total of 1600points resident on a Drive at any time. To help youkeep track of these, locate points 1-20 of each songcan be named on the display—there’s even a handylist of default names to choose from.

The start point: LOCATE 0Each Locate Point is referenced to the start point ofits Song, sometimes called the “sample zero” point.This position, always recallable by the LOCATE 0button, can be edited to create a time offset forsynchronizing to a particular position on a tape-based ADAT, SMPTE time code or MIDI time codesystem. When the Locate 0 position is edited, allthe other location points in the Song will beincremented by exactly the same amount, so theyalways “point” to the same position in the audio,even if the numbers change. For more info aboutthe time display system used in the HD24, see page34.

There are six locate point buttons that can bepressed directly on the front panel (1-6).

How the sample rate affects pointsIf you change the sample rate of a song, its locationpoint display numbers will be automaticallyrecalculated, but the locations themselves do notchange.

For example, a locate point located at 00:05:30:00.0at 48 kHz will be displayed as 00:05:58:05.50 at 44.1kHz. In either case, the location in the music willbe the same.

Special Locate PointsSome of the locate points in the HD24 havespecial functions. They can still be used asstandard locate points, but they also controlautomated functions of the HD24. This sectionlists these “special” locate points. Their functionswill be explained more thoroughly in thefollowing sections.

Locate 0This is always the start of the song. If you store anew value into Locate 0, all of the other locatepoints will change to reflect this new offset.

Locate 1This is the default Loop Start point. If the AutoReturn function is on, the HD24 will go to thispoint when the Loop End point is reached.

Locate 2This is the default Loop End Point. If the AutoReturn function is on, when the HD24 reachesthis location it will jump back to Locate 1.

Locate 21This is the Punch In point. Every time you pressRECORD, (unless Auto Record is ON), the currenttime is stored into this locate point. If you pressAUTO RECORD and arm a track, recording willbegin when the HD24 reaches this location.

Locate 22This is the Punch Out point. Every time youpunch out of record, that time is stored into thislocate point. If the HD24 is in AUTO RECORDmode, recording ends when the HD24 reachesthis location.

Locate 23This is the Edit In point. When you hold SETLOCATE and press EDIT START, the current timevalue is saved to this location.

Locate 24This is the Edit Out point. When you hold SETLOCATE and press EDIT END, the current value issaved to this location.

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To store locate points “on the fly”:

1. Press PLAY to begin playback.


The current time position is transferred into thenext Locate Point, shown in the lower right handside of the display, i.e., if it was showing Locate 03,tapping SET LOCATE will write the current timeinto Locate 04, overwriting whatever was there.

3. To store the current time into a particular locatepoint, hold SET LOCATE and press one of theLocate 1 through 6 buttons.

To select a particular locate point:

The current locate point is shown in the lower righthand corner of the display. This is the point theHD24 will skip to when the LOCATE key is pressed.

1. Press the LOCATE SELECT button. The displaywill read something like this:

L0 1 : “LocNam01”00:00:09:25.25

2. Since the cursor is under the “L01”, press theYES () or NO () buttons to recall any of theother points.

The LOCATE PT display in the lower right cornerwill show the new location point, and thealphanumeric display will show its name and value.

3. Press the LOCATE button to jump to that Locatepoint.

If you want to go to Locate points 0 through 6,these have dedicated front panel buttons.Press LOCATE 0 to jump to the beginning ofthe song, or press the small round 1 through6 buttons under the cursor buttons to move tothose locate points. Doing this does NOTchange the currently-selected LOCATE point,so you can still use the LOCATE button to jumpto that Locate point.

To edit a locate point:

1. Press the LOCATE SELECT button. The displaywill read something like this:

L0 1 : “LocNam01”00:00:09:25.25

In the example above, the display reads 0 hours, 0minutes, 9 seconds, 25 frames and 25 subframes.

2. Press the > (CURSOR RIGHT) button until youhave reached the field (minutes, seconds, etc.)that you wish to edit.

3. Press the YES () or N O () buttons to editthe locate point.

L01: “LocNam01”00:00:09:2 9 .25

Note that even though you’re incrementing byframes (in the above example), it does “roll over”the values above it—if you press YES () in theabove display it will show:

L01: “LocNam01”00:00:10:0 0 .25

since there are only 30 frames in a second(including frame “00”).

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Other Locate CommandsNote that several other functions can be affectedwhen you edit Locate Points:

Auto ReturnWhen this function is on, the HD24 willautomatically jump to the Loop Start pointwhenever the Loop End point is reached.

Auto PlayWhen this function is on, the HD24 will beginplayback automatically after any Locate button ispressed. It can be used in conjunction with AutoReturn to loop playback.

Auto RecordThis function allows you to automatically punchinto and out of record. The Punch In point is presetas Locate 21 and the Punch Out point is preset asLocate Point 22.

To name a locate point:

1. Press the LOCATE SELECT button, then the NAMEbutton to place the cursor under the point’sname.

2a. Use the YES () and NO () buttons to changethe letter, then move to the next letter bypressing the > (CURSOR RIGHT) button.

OR, use this shortcut:

2b. Hold down the NAME button and press the YES() and NO () buttons to scroll through a listof 16 different default names like Intro,Chorus 1, and Solo.

You can edit the list of default names in the sameway if you wish by pressing UTILITY until you get tothis page:


Nam0 1 :“Intro ”

Change any or all of the names, and you will beable to recall them with a single press. Changingthe default list will not affect the name of anycurrent locate point.

Creating A Playback/RecordLoop

The Auto Return function causes the ADATHD24 to automatically rewind back to a specifiedpoint (usually Locate 1) when playback orrecording has reached a specified point (usuallyLocate 2). Both Locates 1 and 2 are assignable toany position using the methods described in theprevious section; however you can redefine anyof the 25 locations in a song as a Loop Start orLoop End point if you wish.

When AUTO PLAY is ON, playback will startautomatically just after you press LOCATE. Byturning on AUTO RETURN at the same time, youcreate a loop that will play the same section of aSong over and over, without having to touch thetransport controls.

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To loop a section of a Song:

The following instructions assume you’ll use thedefault settings for Loop Start and Loop End.

1. Store the position where you want the loop tobegin into Locate 1.

Refer to the previous section for instructions.

2. Store the position where you want the loop toend into Locate 2. This address must be higherthan the address stored in Locate 1.

3. Press AUTO RETURN to enable Auto Return.

On the top of the display, the AUTO-RETURN iconwill appear indicating that Auto Return is enabled.The HD24 will now automatically locate back to theposition stored in Locate 1 upon reaching theposition stored in Locate 2.

If the current Loop Start position is set beyond thecurrent Loop End position and Auto Return ispressed, the display will read:

Error: LoopStart

> LoopEnd

4. Press AUTO PLAY to enable Auto Play.

On the top of the display, the AUTO-PLAY icon willappear indicating that Auto Play is enabled. TheHD24 will now automatically engage playbackupon completing a locate or Auto Return.

5. If necessary, press REW to change the time to alocation that is before the Loop End position.

Alternatively, you can press [LOCATE 1] to locatedirectly to the loop start point and immediatelybegin playback.

6. Press PLAY to engage playback.

The PLAY LED will light and the HD24 will go intoPlay mode. When the Loop End position is reached,the HD24 will automatically locate back to the LoopStart position and then automatically go back intoPlay mode.

To select another locate point as aloop start or end point:

Follow these instructions if you want to use analready-existing location point as a loop start orend point instead of the default values ofLocation 1 and Location 2.

1. Press the LOCATE SELECT button. The displaywill read something like this:

L0 1 : “LocNam01”00:00:09:25.25

2. Since the cursor is under the “L01”, press theYES () or NO () buttons to display thepoint you want to use a Loop Start point.

The LOCATE PT display in the lower right cornerwill show the new location point, and thealphanumeric display will show its name andvalue.

3. Hold the LOCATE SELECT button and press the< (LEFT CURSOR) button to make it the startpoint.

The lower right corner of the display will now looklike this (if you made Locate 8 the new Loop Startpoint):

4. To define the current locate point as a LoopEnd point, hold the LOCATE SELECT button andpress the > (RIGHT CURSOR) button.

The lower right corner of the display will now looklike this (if you made Locate 12 the new Loop Endpoint):

Tip: To find the Loop Start and Loop End pointsfor any Song, enter Locate Select mode andscroll through all the points, until you seethe START or END icons light up next to thenumber in the lower right corner of thedisplay as shown above.




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Automated RecordingSo far, all of your recording has been donemanually — you pressed the transport buttonswhen you wanted to start and stop recording.Auto recording stops and starts recordingautomatically at predetermined times. This isuseful when you want to precisely punch in to aspecific place on one or more tracks, and especiallywhen you need to do it over and over again.

In this section, we will be storing the punch points(called Punch In and Punch Out) “on the fly” whileplayback is engaged. You can, however, manuallymodify the precise Punch In and Out points, as youcan any other Locate point. Auto Return and AutoPlay (described in the previous section) help makeAuto Recording more functional.

To automatically punch in andout:

1. Store the position where you want to beginrecording into L2 1 : “PunchIn ”.

This locate point will contain the timecode valueof the last time you manually punched in.

2. Store the tape position where you want toend recording into L2 2 : “PunchOut”.

This locate point will contain the timecode valueof the last time you manually punched out.

3. Press AUTO RECORD to enable Auto Record.

On the top of the display, the AUTO-REC icon willappear indicating that Auto Record is enabled.

If the current Punch In position is set beyond thecurrent Punch Out position and Auto Record ispressed, the display will read:

Error: PunchIn >


If you see the above, reset the In or the Out sothe Out point is higher than the In point.

4. Press REW or a locate point to rewind beforeLocate 21’s position.

5. Press the Track Record Enable buttons of thetrack(s) you wish to record on.

The selected tracks’ [REC] LEDs will flash.

6. Simultaneously press PLAY and RECORD.

The PLAY LED will light, the RECORD LED willflash and the HD24 will engage Play mode.When Locate 21’s position is reached, the HD24will automatically punch-in (PLAY, RECORD andtrack REC LED(s) will stop flashing and remainlit). Recording will continue until Locate 22’sposition is reached, at which point the HD24 willautomatically punch-out, returning to play mode(PLAY LED lit, RECORD LED off, track REC LEDsflashing).

7. Press STOP to stop the transport.

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If none of the tracks are in record-ready (all

[REC] LEDs off) when Play and Record arepressed, the display will read No

Tracks Armed.

If a record is initiated past Locate 21’s

position, but before Locate 22’s position,then record is entered immediately. If therecord is initiated after Locate 22’s position,then the record command is ignored and theHD24 will continue in play mode.

RehearsingBy pressing the REHEARSE button (the REHEARSEicon will light in the display), you can run throughthe Auto-Record process without actuallyrecording anything. However, if the AUTO INPUTfunction is turned on, the input monitors on thetracks that enabled for recording will switch fromplayback to input when the punch-in occurs, andback to playback when the punch-out occurs. TheRECORD LED will continue flashing throughout thepunch in and out. This way you can try out yourpunch locations first without recording overanything. In other words, you can measure twice(or more), and cut only once!

Tip: Press the Rehearse button, arm a track, thenpunch in and out of record, storing newvalues in Locates 21 and 22, to quickly setPunch In and Punch Out points for AutoRecording.

Tip: Combining Auto Record andLooping

When recording a difficult segment, it maybe helpful to use all the features we’vecovered in this chapter at the same time.Usually, you’ll set a loop that starts a fewbars before a punch in point and ends abar or two after, so you have a “pre-roll”and “post-roll” automatically. You can hitSTOP at any time, then press the LOCATE 1button to start the loop at the beginning.Don’t forget to turn AUTO INPUT on so youcan hear the track before and after thepunch-in.

Don’t forget about two other aids to recording:the punch-in footpedal and the LRC remotecontrol. The LRC has buttons for turningAuto Record, Auto Play, Auto Return, andRehearse on and off. The punch-in pedalcan be used to set the Punch In and PunchOut points, as long as Auto Record is off.

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Working with DrivesMounting and selecting a drive

One of the key strengths of the ADAT HD24 is itseasily-removable hard drives; in fact it was ourgoal to make the drive caddies similar to ADATtapes in their transportability and low cost. Yoursystem becomes much more flexible when you addadditional drives. Without shutting down yoursystem, you can simply insert a drive and play orrecord on it. You don't have to wait for adownload or a backup—it's available just as if itwere a tape. But there are certain drive modes youneed to understand: when and how a drive ismounted and unmounted, and when it is selected.

Each of the two hard disk drive bays has anassociated DRIVE button that performs two majorfunctions: selecting the drive for use, andpreparing the drive for removal from the machine(dismounting and power-down). Associated witheach drive select button is a two-color LED thatindicates the status of the hard drive. When thisLED is lit (either green or flashing red), the drive ismounted. Mounting means that the systemrecognizes the disk, has powered it up, and cancommunicate with it.

Before you can pull out a drive, it must bedismounted (DRIVE LED must be OFF). Otherwise, you run the risk of a head crashand losing data.

What happens when a drive mountsWhen a drive gets mounted, if the drive containsa valid ADAT FST™ format, the machine willautomatically enter Song Select mode andattempt to select the most recently selected Song,or Song 01. If there are no songs on the disk, thedisplay will indicate "No Songs On

Disk"—but all you have to do is press the NEWSONG button and you're ready to record. If thedrive is not recognized as having the ADATFST™ format, the display will show "InvalidFormat", and you'll have to initialize the disk(after making sure there's nothing valuable insome other format on the disk).

Which drive is selected?When you have hard disks mounted in bothdrives, remember that just because a drive ismounted and its LED is green doesn't mean theHD24 is actively using it at any given moment.Only one drive can be active or selected at anygiven time…you can't record or play back audioon two different drives simultaneously.

The indicator for which drive is the currently-selected drive is in the upper right hand corner ofthe display:

In this display, Drive 2 is the active drive, andthere are 34 minutes of free space at the currentsample rate and track width. The HD FREESPACE indicator shows available recording timein hours, minutes, or seconds, as indicated by an“H”, “M”, or “S” to the right of the number.


342 M

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How Drives Get MountedWhen power is turned on and a drive is present, itwill be mounted automatically; you don't need totake any action unless a drive was deliberatelydismounted.

If no drive is presentIf the ADAT HD24 is powered on with no drives inits bays, the display will (after the startup "splash"screen) show the following message:

No Disk Drive


When a drive caddy is insertedIf you push a caddy into the first drive bay, themachine will automatically detect that the drive isthere, will apply power and try to mount the drive.

If the ADAT HD24 already has one active selecteddrive in one bay and a drive is inserted in the otherbay, the machine will not attempt to apply powerand mount the drive until after that drive'srespective DRIVE button is pressed.

If a drive is presentIf the ADAT HD24 is powered on with one drive inits bay, the machine will automatically detect thatthe drive is there and will apply power and try tomount the drive.

If it is powered on with two drives in its bays, themachine will automatically detect that both drivesare there but will only apply power and try tomount the drive that was being used before theHD24 was turned off.

Dismounting drives

Before you can pull out a drive and replaceit with another one, it must be dismounted(DRIVE LED must be OFF). Otherwise, yourun the risk of a head crash and losingdata.

To dismount a drive:

1. Press the DRIVE button.

The display will read "DismountDrive? Y /N".

2. Press the YES () button.

3. Wait while the drive is powered off and theheads are parked.

The display will read "Dismount HD1..." with a progress bar on the bottom lineand the DRIVE LED will flash red.

4. When the display is clear and the DRIVE LEDis completely off, you may pull out the driveby pulling on the handle.

If there are no other drives in the machine after adrive dismount procedure, the display will showthe following message:

No Disk Drive


Tip: If there are two mounted drives in thebays, and Drive 1 is the selected drive,press and hold the DRIVE 2 button for twoseconds to dismount Drive 2 without firstselecting it for use. The same logic holdsfor Drive 1.

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To manually select a drive:

Pushing the DRIVE button of a drive whose LED isoff will attempt to mount and select that drive. Ifthere is a drive in the bay with a valid format, thedrive will be selected, but with the followingexceptions:

• You can't select a drive while the other is inRECORD mode.

• If you select a drive while the other is in PLAY,the unit will automatically STOP.

• If there is no drive in the caddy, pressing DRIVEwill do nothing.

The HD FREE SPACE display in the upper rightcorner will show that the new drive is active, andhow much recording time is available.

Adding additional drivesYou can obtain additional HD24 drive caddies fromyour Alesis dealer. You may install hard disks in acaddy yourself, or the dealer may have themavailable with disks installed. In any case, thedrive should be set to “master” or “single” modebefore installation, following the drivemanufacturer’s instructions.

Disk size and recording timeA 20 GB (gigabyte) hard disk will give youapproximately 90 minutes of 24-track, 24-bitrecording time at the 48 kHz sampling rate, or 2,160track minutes. If some Songs on the disk areinitialized with fewer tracks, you gain morerecording time. The HD24 doesn't care how largethe disk is—it can be as much as two terrabytes(2000 GB) in theory, although there is no such drivethat can fit in a 3.5" disk tray at the moment. Themore GB, the more recording time (and, generallyspeaking, the lower cost per minute).

Formatting disks

Before a disk can be used by the HD24, it must beformatted in the special ADAT FST™ formatinvented by Alesis engineers. This is no big deal,and takes only a moment.

There are two formatting procedures available toyou:

Quick Format

• initializes the disk directory in the ADAT FSTformat, but does not actually erase andreformat every sector on the disk. This isadequate for new disks and most cases whereyou want to start over.

Long Format

• checks, erases and formats every single sectorof the disk, ensuring that all previous data iserased. It also eliminates any bad sectors ofthe drive. This takes longer, but werecommend you perform a long formatwhenever possible. It must be used if thedrive in the caddy has been used in acomputer before, or if you want to ensurethat no trace of previous recording on thedisk can ever be recovered.

1. The type of format is determined on page 2 ofthe Utility menu. Press UTILITY until the topline of the display reads:

Util02:HD Format

Quick Format? Y /N

2. If you want to change the type of formatshowing on the lower line of the display,press the < (CURSOR LEFT) button to place thecursor under the format type.

3. Press the YES () or NO () buttons to selectthe desired format type to the other drive. (Inthis example, pressing will change thedisplay to read:)

Util02:HD Format

Long Format? Y /N

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4. Press the > (CURSOR RIGHT) button to place thecursor under “Y/N” in the display.

5. Press the YES ( ) button to begin formattingthe drive.

If, upon trying to select a drive for use, the machinedetermines that a disk's format is invalid, thedisplay will prompt:

Invalid Format

Format Disk? Y /N

Simply press the YES () key if you know the diskis a new one being inserted for the first time.

If you see this message on a drive youthought was already formatted, dismountand pull out the drive immediately. If youformat a disk with data on it, the old datawill be lost permanently!

Pressing NO () will dismount the disk, and eitherre-select the other drive (in the case of two drives),or display "No Disk Drive Selected". Pressing theYES () button will further prompt:



Pressing NO () will return to the "Invalid Format"display. Pressing YES () will begin the formattingprocess, and will display:

Formatting Disk

===== (51%)

After the format is complete, the machine will enterSong Select mode, and because after a format therewill be no songs on the disk, the display willindicate "No Songs On Disk".

LED OperationThe Drive Select LEDs are bi-color LEDs thatindicate the status of the hard disk drive. When adrive bay is empty, its drive select LED will beoff. If there is a drive in a bay, but it isunmounted, the LED will also be off.

If a drive is inserted into a bay and mounted, itsDrive Select LED will illuminate solid greenindicating that the drive has power and is unsafeto remove.

While a disk is being dismounted, the LED willilluminate solid red for a period of approximately7-10 seconds while the drive spins down, afterwhich it will extinguish completely.

Disk reads and writes will cause the LEDs totemporarily flash red.

To scan a drive for errors:

Utility 3 of the HD24 may be used to correctproblems with the file system. Such errors mayoccur if a drive is removed from the caddy andplaced into a computer, or if the HD24 was shutdown in the middle of a recording. For example,if you scroll through the list of songs on a disk,and notice that the song length is in error, that isprobably a file system error.

1. Press UTILITY until the display reads:

Util03:HD Scan

Scan Disk? Y /N

2. Press the YES () button.

Scan and Recover

Hard Disk X? Y /N

If you press at this point, the HD24 will gothrough a procedure for a period of time toscan the disk and reassign data fromquestionable sectors.

Do not disturb the scan/recover process to avoidloss of data!

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To get information about the harddrive:

If you need information about a hard disk in adrive bay (usually to check for compatibility ifthere are some problems), use Utility 4 .

1. Press UTILITY until the display reads:

Util04:HD Info

M odel: FUJITSU ->

On this screen, press the > (CURSOR RIGHT)button to see the rest of the model name.

2. Press the < (CURSOR LEFT) button to place thecursor under “Model”. Press the YES ( )button to see the following screens:

Util04:HD Info

V er: XXXX

This shows the disk version.

Util04:HD Info

S ize: 9.5 GB

This shows the total data capacity of the disk.

Util04:HD Info

F ile Sys: 1.00

This shows the file system the disk was formattedwith.

Press another button such as SONG SEL or LOCATESELECT to leave Utility mode.

To install an IDE drive into acaddy:

1. Obtain an IDE drive from your music dealer,computer or office supply store. The driveshould be the standard 4” size with a spindlespeed of at least 5400 rpm. Read themanufacturer’s installation instructionscarefully.

In particular, make sure to set each IDE drive to“MASTER” (in some cases, “SINGLE”)mode, using jumpers or small switches onthe drive. Even though there are two drivesin the HD24, each one should be set toMASTER mode.

2. Pull the empty drive caddy from the HD24.Open the top of the caddy by sliding itbackwards.

Use only Alesis-manufactured drivecaddies in the HD24. Removable drivebays from other manufacturers are NOTCOMPATIBLE and will damage the HD24.Extra caddies are available from yourAlesis dealer.

3. Plug the power cable (with the yellow, red,and black wires) of the caddy into thereceptacle on the drive.

4. Plug the multipin cable (the wide grey cable)into the drive.

5. Carefully place the drive in the caddy, beingcareful not to pinch the wires.

6. With the drive in position, look for thethreaded sockets on the side of the drive thatalign with the slots on the side of the caddy.Secure the drive in place with the screwsprovided, at least two screws per side.

Alternatively, you may secure the drive to thecaddy through the bottom plate.

7. Insert the drive into a bay and format itaccording to the procedure in the previoussection.

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Backing up your workBecause the ADAT HD24 has two removable drivebays, you can make a safety copy of your valuablerecordings right in the unit, as long as you havetwo drives. While hard drives can run forthousands of hours without maintenance, and storedata without decay for many years, hard drive“crashes” due to mechanical abuse or wear are stillpossible. Especially if you’re carrying the HD24 onthe road, back up your data often.

To copy a whole song from onedrive to another:

First make sure you have mounted and powereddrives in both bays. Both DRIVE LEDs should begreen. Use the DRIVE button to select the sourcedrive (that holds the song you want to copy).

1. Press the UTILITY button until you get to the firstpage, looking something like this:

Util01:HD Copy

Song01->HD1? Y /N

2. To select another Song to copy, press the< (CURSOR LEFT) button to place the cursorunder the Song number.

3. Press the YES () or N O () buttons to selectthe desired song to copy to the other drive.

4. Press the > (CURSOR RIGHT) button to place thecursor under “Y/N” in the display.

5. Press the YES () button to copy the song to theother drive.

To copy the contents of the entiredrive:

Follow the instructions for copying a song, but atstep 3 keep pressing YES () until you see “AllSongs” in the display:

Util01:HD Copy

AllSongs->HD1? Y /N

Alternatively, you can back up your work to acomputer hard disk via Ethernet. Seechapter 9: Using Ethernet.

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EditingOne of the key benefits of recording to a hard diskrecorder such as the HD24 is the ability to edit yourperformance. The HD24 allows you to copy aperfect rhythm guitar part to every chorus, move abass solo to a later chorus, even undo a bad edit.

This section will introduce you to the editingcontrols on the HD24, then walk you through somecommon editing techniques.

Editing Controls

The buttons below and to the left of the display eachcontrol an Editing function:

Track EditThis control selects which tracks will be edited. Touse this feature, hold down the TRACK EDIT buttonand press one of the Track record enable buttons (1,2, etc.) A blue box will surround the meter of anytrack(s) selected for editing.

Edit StartThis button stores the time where the edit willbegin. To store an Edit Start time, hold the SETLOCATE button during playback, then press EDITSTART. Or, enter a particular number into Location23 “Edit In” using LOCATE SELECT as described onpage 44.

Edit EndPress this button to mark the end point of a Cut orCopy edit. To store an Edit End point, hold SETLOCATE during playback, then press EDIT END. Or,enter a particular number into Location 24 “EditOut” using LOCATE SELECT as described on page 44.

CutThis function cuts all of the audio on selectedtrack(s) from the Edit Start point to the Edit Endpoint, leaving silence in the area you just cut. Youwill be able to Paste this audio to a different locationof the recording, even on a different track or adifferent Song on the same drive.

CopyThis function copies all of the audio on selectedtrack(s) from the Edit Start point to the Edit Endpoint. The audio you copy will remain untouched,and you will be able to Paste this audio to adifferent location, track, or Song.

PasteThe Paste command pastes the audio that you haveselected in a Cut or Copy command and pastes it atthe time selected in the Edit Start location on theselected track(s). This audio will replace whateverwas previously on that track.

UndoThe Undo button reverses the last command. Forexample, if you don’t like the results of a Pastecommand, pressing UNDO will return the recordingto its previous state.

The HD24 features up to 99 levels of Undo,depending on the size of the edits and whether the“Paste Undo” utility is turned on or off. See page62.

Set LocateThis button allows you to define a Locate point, EditStart point or Edit End point. To use this function,hold the SET LOCATE button and press EDIT START,EDIT END, or one of the Locate buttons.

If all these commands seem confusing, don’t worry.The next section will walk you through a fewcommon editing tasks.

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Using the Edit Start and Edit EndPoints

Setting accurate EDIT START and EDIT END points willbe critical to every edit you make on the HD24.This section will explain how to make the most ofthese functions.

Setting an Edit Start or Edit EndPoint

Edit Start and Edit End points will be used for everytype of edit. This section will explain how to set anEdit Start or Edit End point “on the fly”.

1. First, record some audio into a song so you canhear what you’re editing.

2. Press PLAY. (You can also set an Edit Start pointwhile stopped, but this method allows you tohear what you’re doing.)

3. Press and hold the SET LOCATE button.

4. When you reach the point where you want aCut, Copy or Paste to occur, press EDIT START.

Setting an Edit End point uses the same procedure,only you press EDIT END when you reach the locationwhere a Cut or Copy should end.

Previewing the Edit Start and EditEnd Points

The ADAT HD24 offers a convenient, automaticway to hear the edit points which you just marked.During a preview, you’ll only hear tracks that havebeen selected for editing using the TRACK EDIT key(or, if no tracks are selected, you’ll hear all tracks).

1. Press the EDIT START button. The display shouldlook like something like this:

L2 3 : "Edit In "


This example display shows that the Edit Start point(Locate Point #23) occurs at 0 hours, 0 minutes, 52seconds, 17 frames and 54 subframes into the song.

2. Press the EDIT START button again. You shouldhear the song begin to play from the pointwhere you set the Edit Start point, thencontinue for 5 seconds after. While the HD24 is

previewing your Edit Start location, the displaywill read:


Edit Start

3. Press the Edit End button. The display shouldlook like something like this:

L2 4 : "Edit Out"


This example display shows that the Edit End point(Locate Point #24) occurs at 0 hours, 0 minutes, 55seconds, 10 frames and 4 subframes into the song.

4. Press the EDIT END button again. You shouldhear the song begin to play from 5 secondsbefore the Edit End location, then stop at theEdit End point. While the HD24 is previewingyour Edit Start location, the display will read:


Edit End

5. To preview the entire edit region, from EditStart to Edit End, press the EDIT START and EDITEND buttons simultaneously. The HD24 willplay from the Edit Start point to the Edit Endpoint, and the display will read:


Edit Region

You can press STOP at any time to stop playbackof a preview.

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Adjusting the Edit Start and EditEnd Points

Edit Start and Edit End points can be adjusted intwo ways: by using the cursor keys or by using thescrub feature.

Adjusting Edit Start and Edit Endpoints using the Cursor Keys

When the Edit Start or Edit End point is shown inthe display, you can edit their location with thecursor buttons. This gives you exact control overtheir location, accurate to .0003 seconds. To adjustthe Edit Start location:

1. Press the EDIT START button. The display shouldlook like something like this:

L2 3 : "Edit In "


This example display shows that the Edit Start point(Locate Point #23) occurs at 0 hours, 0 minutes, 52seconds, 17 frames and 54 subframes into the song.

Note that the Location point (#23) is currentlyselected.

2. Press the > (CURSOR RIGHT) button. This willselect the Hours field of the Edit Start point.

3. Since we’re probably not that far off on our edit,press the > (CURSOR RIGHT) button to move tothe Minutes field, Seconds field, Frames fieldand Subframes field.

4. When you’ve selected the field you wish to edit,press the YES () or NO () buttons to adjustthe value.

5. When you’re finished, press the EDIT STARTbutton to hear the new Edit Start location.

You can use this same procedure to adjust andpreview the Edit End location.

Adjusting Edit Start and Edit Endpoints using Audio Scrub

The HD24 allows you to scrub the audio to find theoptimum Start or End point for your edit.

1. Press and hold STOP.

2. Press and hold the F F W D button to scrubforward in time.

3. Press and hold the R E W button to movebackwards in time.

4. When you have scrubbed to the location whereyou want an edit to begin, release all of thekeys.

5. Hold SET LOCATE and press EDIT START or EDITEND to set a new location for these points.

Note that only the tracks that are currently in TrackEdit mode will be heard during the scrub. If notracks are selected, all of the tracks will scrub.

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Using the Cut and CopyCommands

The Cut and Copy commands place the audiobetween the Edit Start and Edit End points fromedit-selected tracks into a buffer. This audio canthen be pasted elsewhere in the song.

Cutting an Audio Region

This procedure cuts the selected tracks between theEdit Start and Edit End points, leaving silence in itsplace.

1. Set an Edit Start and Edit End point, asdescribed in the previous sections.

2. Press and hold the TRACK EDIT button, then pressthe Track Record Enable button of the tracksyou want to cut.

A box will appear in the Meter Bridge around themeters of the selected tracks.

3. Press CUT. The display will read:

Cut Selected

Region(s)? Y /N

4. Press the YES () button to confirm the cut. Thedisplay will read:

Cut Region(s)

Are You Sure? Y /N

5. Press the YES () button one more time toconfirm the operation.

If you haven’t set the Edit Start and Edit End pointsproperly, you will see this an error message on thedisplay:

Error: EditStart

≥ EditEnd

6. You will see a progress bar while the audio isbeing copied, then the display will read:

Track Cut


Copying an Audio Region

This procedure copies the selected tracks betweenthe Edit Start and Edit End points, leaving theoriginal recording untouched.

1. Set an Edit Start and Edit End point, asdescribed in the previous sections.

2. Press and hold the TRACK EDIT button, then pressthe Track Record Enable button of the tracksyou want to cut.

A box will appear in the Meter Bridge around themeters of the selected tracks.

3. Press COPY. The display will read:

Copy Selected

Region(s)? Y /N

4. Press the YES () button to confirm that youwish to copy. The display will read:

Copy Region(s)

Are You Sure? Y /N

5. Press the YES () button one more time toconfirm the operation.

If you haven’t set the Edit Start and Edit End pointsproperly, you will see this an error message on thedisplay:

Error: EditStart

≥ EditEnd

6. You will see a progress bar while the audio isbeing copied, then the display will read:

Track Copy


Remember that there’s a limit of how much datacan be cut and pasted at a time (72 trackminutes, or 36 minutes if Paste Undo is on).For more information on the edit buffer, seepage 62. If the region is too large to cut orcopy, simply de-select some tracks. You cando a second cut/copy operation on thosetracks later.

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Cutting entire tracks

Instead of cutting between the Edit Start and EditEnd points, it is possible to cut the entire track ortracks selected for editing.

1. Press and hold the TRACK EDIT button, then pressthe Track Record Enable button of the tracksyou want to cut.

A box will appear in the Meter Bridge around themeters of the selected tracks.

2. Press CUT. The display will read:

Cut Selected

Region(s)? Y /N

3. Press the < (CURSOR LEFT) button to place thecursor under the word “Regions” in the display.

4. Press the YES () (up) button. The display willnow read:

Cut Selected

T rack(s)? Y/N

5. Press the > (CURSOR RIGHT) button to place thecursor under the “Y/N” in the display.

6. Press the YES () button to confirm the cut. Thedisplay will read:

Cut Track(s)

Are You Sure? Y /N

5. Press the YES () button one more time toconfirm the operation.

6. You will see a progress bar while the audio isbeing copied, then the display will read:

Track Cut


To copy entire tracks:

Follow the procedure for cutting tracks, but pressthe COPY button instead of the CUT button.

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Using the Paste CommandThe Paste function is used in conjunction with theCut and Copy functions. This function allows youto use the audio that you’ve cut or copied in anothersection of the song, another track, or even anothersong.

Pasting audio into a song may require that the songbe lengthened. If so, the HD24 will do thatautomatically.

Pasting audio to a new location

Most Paste operations involve cutting or copying amusical phrase from one section of a song andmoving it to another location in the same song.

1. Cut or copy audio from another section of thesong, using the procedure described in theprevious sections.

If you’re pasting into different tracks than youcopied from, deselect the original source tracks bypressing and holding the TRACK EDIT button, thenpress the Track Record Enable buttons of the selectedtracks.

2. Press and hold the TRACK EDIT button, thenselect the tracks that you want to paste into.

If you are pasting into the same tracks that youcopied from, you can skip this step and leave theoriginal tracks selected.

3. Press the PASTE button when you’re ready topaste the audio. The display will read:

Paste To

Edit Start? Y /N

This warning reminds you that you’re about tooverwrite any audio from the current Edit Startpoint to the end of the region that you’re pasting.

• If you want to paste to the current Edit Startlocation, jump to step 6.

• To check the Edit Start location, press theEDIT START button. If it’s not what you want,set a new Edit Start point using any of themethods described on page 56, “Using theEdit Start and Edit End Points”.

OR• you may paste the data to the song start or

region start point as shown in the nextcolumn.

To paste to the start of the track:

a. Press the < (CURSOR LEFT) button to placethe cursor under the word “Edit” in thedisplay.

b. Press the YES () (up) button. The displaywill now read:

Paste To

T rack Start? Y/N

This warning reminds you that you’re about tooverwrite any audio from the beginning of the songto the end of the region that you’re pasting.


To paste to the same time location theregion was originally cut or copiedfrom:

c. Press the < (CURSOR LEFT) button to placethe cursor under the word “Edit” or“Track” in the display.

d. Press the YES () button. The display willnow read:

Paste To

R egion Start?Y/N

This warning reminds you that you’re about tooverwrite any audio from the original time stamp theregion was cut or copied from to the end of the regionthat you’re pasting.

6. No matter which start point methodyou use, press the YES () button. Thedisplay will read:

Track Paste

Are You Sure? Y /N

7. Press the YES () button to confirm the paste.The display will draw a progress bar while it’spasting the audio, then it will read:

Track Paste


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Pasting Audio to a Different Song

You can use the PASTE command to move audio to adifferent song. This is often used to copy tracksfrom an 8-track song into a 24-track song for moreavailable tracks.

You could use this technique to save a copy of asong, so that the original stays untouched; butin most cases copying an entire song is moreefficient using Utility 01 (because it won’t useup the edit buffer space).

To Paste tracks into a different song:

1. Cut or Copy audio from entire tracks or anysection of the song, using the proceduresdescribed in the previous sections.

2. Press the SONG SEL button, then press the YES() or NO () buttons to select a new song.

Note that you can’t paste into a song with a differentSample Rate.

3. Press and hold the TRACK EDIT button, thenselect the tracks that you want to paste into.

When you changed songs, the selected tracks wereautomatically cleared.

4. Press the PASTE button when you’re ready topaste the audio. The display will read:

Paste To

Edit Start? Y /N

You may check this point by pressing the audiousing the EDIT START button. Note that theEdit Start point of each Song inthe HD24 is unique. The Edit Startof the source Song is probablydifferent from that of thedestination Song.

If necessary, set a new Edit Start point using any ofthe methods described on page 56, “Using the EditStart and Edit End Points”.

OR, if you wish, you can use the procedure on theprevious page to change the display to:

Paste To

T rack Start? Y/N


Paste To

R egion Start?Y/N

5. Press the YES () button. The display will read:

Track Paste

Are You Sure? Y /N

6. Press the YES () button to confirm the paste.The display will draw a progress bar while it’spasting the audio, then it will read:

Track Paste


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UndoThe undo command reverses the effects of previousedit commands. Multiple levels of undo areavailable (with certain restrictions on size). Forexample, if you don’t like the results of a PASTEcommand, you can press UNDO to return therecording to its pre-paste state. Pressing UNDOagain will (for example) undo a CUT operation thathappened before the paste, and so on, up to 99operations.

NOTE: You can’t undo a recording, deleting a song,or any other function besides CUT, COPY, orPASTE.

The Edit Buffer and Levels of UndoThe ADAT HD24 uses a special area of the harddisk to store data used for editing operations. Thisedit buffer can save a copy of any original audio thatwill be destroyed by an edit operation, as well asthe edit data itself. This prereserved edit bufferholds up to 72 track-minutes of 48 kHz data (3minutes of 24 tracks). These track minutes are NOTpart of the free space on the disk used for recording;they’re always available even if you have no “HDFree Space” left.

In most practical applications, this space is morethan enough to undo a bunch of previous edits ifyou decide you’ve made some mistakes. We say“up to 99 levels” of Undo because this edit buffer is“revolving”—it tries to save as many previous editsas possible, but starts erasing old edits if it needsspace for new ones, without warning. Luckily, inmost cases edits are performed on only a few tracks,and are 10-20 seconds long. Usually, you’ll be ableto UNDO back through several generations ofediting (most likely, more than you’ll remember!).

A feature called paste undo on/off allows you to getmore mileage out of the buffer. At its most extreme,if you cut 90 seconds across all 24 tracks, and pastedit in a different location, you’d have only one levelof Undo: half the buffer is used for the cut data, andhalf for the data being pasted over. In this case, theHD24 would have to delete all the old UNDOs inthe “stack” to get the space to perform the paste. IfPaste Undo was set to off, half of the buffer (36track-minutes) and some previous UNDOs wouldstill be available–but you’d better be sure you’repasting over track segments you don’t want!

The following actions will also erase theedit buffer:

• Selecting a different drive• Turning off the unit• Changing to a different Song (except the last

CUT or COPY will be preserved, so you canpaste between songs).

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Using the Undo command

First, perform a Copy, Cut or Paste command.

Press the UNDO button. If your last operation was aPaste command, the display would read:

Undo Last

Track Paste? Y /N

Press the YES () button. The display should read:

Undo Track Paste

Are You Sure? Y /N

Press the YES () button. You will see a progressbar on the display, then it will read:



Paste Undo On/Off

If the Paste Undo function doesn’t work, make surethat it’s turned on in the Utility menu. Press UTILITYuntil you reach page 9:


Paste Undo: O ff

Press YES () to enable the Paste Undo function ifit’s disabled, or NO () to disable it.

The two reasons to turn Paste Undo OFF:

• Speed. If the HD24 doesn’t have to make acopy of existing data before pasting new data,paste operations will take place much faster.

• Conserving disk space to copy andpaste larger regions. With Paste UndoOFF, the edit buffer can be used to store all copydata. No space needs to be “held back” to storeundo data.

CUT and COPY are always UNDO-able; they are notdisabled by Utility 9 “Paste Undo: Off”

Track SlipThe Track Slip function is similar to the Track Delayfunction in tape-based ADAT recorders. UsingTrack Slip, however, audio can be delayed oradvanced in time up to 170 milliseconds (0.17seconds).

The Track Slip function can only be applied to entiretracks at once, not to a region. Edit Start and EditEnd points do not affect this function.

Turn Track Slip off before attempting to record. TrackSlip can be used only during playback, notduring recording.

Using Track Slip

Press the TRACK SLIP button. The display shouldread:

Track Slip OFF

Track0 1 > 000.0ms

1. Press the < (CURSOR LEFT) button until you haveselected the word OFF. Change this to ON bypressing YES ().

This setting allows you to toggle Track Slip offwithout losing the settings of your individual tracks.

2. Press the > (CURSOR RIGHT) button to select theTrack Number field.

3. Press the YES () or NO () buttons to select thetrack you wish to Slip.

Track Slip OFF

Track0 5 > 000.0ms

4. Press the > (CURSOR RIGHT) button to select thetime field. Pressing the YES () or N O ()buttons will change the Track Slip time inmilliseconds.

5. Press the > (CURSOR RIGHT) button again to editthe Track Slip time in 1/10ths of a millisecond.

6. Press both the YES ( ) and N O () buttonssimultaneously to return the Track Slip time to000.0ms.

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More about editingIf you’re familiar with digital audio editing, youknow that an abrupt change from one region toanother when making an edit can cause a “click” or“pop”. This would happen if the sample numberjumps drastically from the original material to thepasted material. For this reason, all digital audiorecorders use crossfade regions when performingan edit or punch-in on existing material.

On the ADAT HD24, a 10 millisecond longcrossfade region is automatically created at both thebeginning and end of an edit. In most cases, thiswon’t affect the performance of your edits, but insome rare situations, keep the following illustrationin mind:

-10 ms +10 ms



As you can see, the crossfade region starts 10 ms.before the actual EDIT START point. A crossfaderegion continues for 10 ms. after the EDIT ENDpoint. Therefore, the pasted region actually affects20 more milliseconds of a track than the differencebetween EDIT START and EDIT END wouldindicate.

Tip: This is a reason to use PASTE UNDO if youdon’t like a paste. Though it might seemsimpler to simply cut and paste some new datato the same edit points without undoing thefirst paste, if you do so the new crossfaderegions will be a mix of three different “takes”:the original, the first paste, and the final paste.If the audio starting the first paste is drasticallydifferent from the final one, it’s possible thatvery short “blips” could be audible around theedit points.

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High resolution operation88.2/96 kHz sampling rates

The ADAT HD24 has the capability of recording attwice the conventional sample rate. You can recordand play back at 88.2 kHz (double the consumerrate of 44.1) or 96 kHz (double the professionalrate).

The HD24 can always record and play back high-resolution signals via its ADAT Optical ports. Butits analog I/O, as shipped from the factory, is onlycapable of operation up to 48 kHz. Your Alesisdealer can install an optional upgrade kit thatallows analog input and output at the highersample rate (see page 66).

By recording at these high sample rates, frequencyresponse is doubled: instead of going to 20 kHz,response is flat to beyond 40 kHz. But there aresome factors you should be aware of beforerecording at these higher rates:

The tradeoffs• At these higher rates, the HD24 becomes a

twelve-track (maximum) recorder, not 24-track.• On a per-track minute basis, the available

recording time is cut in half since there aretwice as many samples being recorded to thehard disk,

• Many other digital devices—notably mostdigital mixing consoles and many computerworkstations—don't have 96 kHz capability, orhave compromised operation when they do(less DSP, for example).

• Many sources in the studio such as mostmicrophones and almost all digital keyboardshave no response above 20 kHz that can berecorded anyway.

• Most studio speakers aren't capable ofreproducing above 20 kHz, and whenpresented with those higher frequencies thespeakers exhibit modes and resonances.

• Most experts believe that higher frequenciesabove 20 kHz are not audible to the majority oflisteners.

However, formats such as DVD are capable ofbringing 24-bit, 96 kHz audio all the way to theconsumer, and to be able to have the best possible

masters in the future, a high sample rate may bethe way to go.

Ensuring sample-rate compatibilityBefore you start recording a session at a highsample rate you should plan your mixing andmastering process so that you don’t run intoproblems later. Some of the questions youshould ask:

• If you are mixing digitally, does your digitalconsole support high sampling rates?

• Are you recording any digital sources such assamplers or external A/D converters, and dothey support this sample rate?

• Does your mixdown device record at thissampling rate?

• If you are taking the project to a masteringfacility after mixdown, can they process an88.2 or 96k project?

• Finally, do you have the hard drive space torecord this project? Remember that 88.2 and96kHz projects use twice as much drive spaceper track as 44.1 and 48k projects.

88.2 kHz is a good choice if the tracks will bemixed digitally to a Compact Disc format. Thesample rate conversion to convert this to the44.1kHz rate used for Compact Discs is minimalcompared to the conversion required for 96kHzrecordings—you simply use every other sample.

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How ADAT Optical handles a 96 or88.2k signalThe ADAT Optical “lightpipe” was designed tosend eight streams of 24-bit digital audio data atstandard sampling rates. When it is used for high-resolution audio, it isn’t “sped up” but instead usestwo channels to send the data for one track,sending it at standard speed with some special bitsset in the code that tell the receiver to decode it as ahigh-speed 4-channel interface instead of astandard-speed 8-channel interface. Track 1 sendsodd-numbered samples down channel 1 of the"lightpipe" and even-numbered samples downchannel 2. Track 2 uses channels 3 and 4, Track 3uses channels 5 and 6, and Track 4 uses channels 7and 8.

This allows compatibility with mixers and olderADATs that can't handle the higher sample rate.As far as they're concerned, they're seeing twodifferent 44.1 or 48 kHz signals; if you listenthrough them, they'll sound basically identical. Butdevices that can read the User bit* in the ADATOptical subcode, identifying it as a high-samplerate signal will automatically decode it as fourhigh-sample rate signals.

* There are some ADAT Optical devices thatare 96/88.2k capable, but which do not setor read this user bit. These can still work withthe HD24, but the HD24’s sample rateindicator will flash to show that a possibleinconsistency has been detected.

However, even though a recorder or mixer canread these pairs of ADAT signals, you may not beable to work with these files. For example, if yourecord a stereo 96kHz recording to four tracks ofDigidesign’s Pro Tools® , cut and paste the tracksand play them back into the HD24, the tracksshould record back in fine. However, if you try toadd a crossfade, EQ these tracks, or process thetracks in other ways, you won’t be able to recordthem back into the HD24 at 96kHz.

Using the HD24 with anexternal High Sample Rate-capable A/D or D/A converter

The HD24 can be used to record the output of aA/D converter which converts at 88.1 or 96kHz.

To record a digital signal at96kHz:

1. Press NEW SONG and select “96.0k” as yoursampling rate.

See page 32 for more information on creating anew song.

2. Plug the ADAT Optical output of your A/Dconverter or digital mixer into the DigitalInput of the HD24.

3. Press the INPUT SELECT button until the HD24is set for Digital input.

If there is not a 96k Analog Input board installed,the only choice will be Digital.

4. Press the CLOCK SOURCE button until thedisplay reads Optical.

5. Press the Record Enable buttons on the tracksyou wish to record on, then press RECORD.

The optional 96k Analog I/Oboards

Alesis offers an optional set of converter circuitboards which, when installed, allow you torecord and play back at 88.1kHz or 96kHz usingthe 1/4” analog inputs and outputs. Without thisoption, 88.1k and 96k recording is available onlythrough the digital inputs.

For more information on the 96k Analog Inputboard, contact your Alesis dealer or visit theAlesis website (

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Synchronization and MIDISynchronization

MIDI Time CodeThe HD24 can generate 30 fps MIDI Time Codefrom its built-in MIDI output. This is the preferredmethod of synchronizing a MIDI sequencer ordrum machine to the HD24.

To generate MIDI Time Code:

1. Press the MIDI button until you reach Page 2,the MTC page.


Generate MTC? N o

2. Press the YES () button to change this settingto Yes.


Generate MTC? Y es

3. Press PLAY. The HD24 will begin generatingMIDI Time Code starting from the value shownin the display.

The HD24 cannot be a slave to MIDI Time Codewith the built-in MIDI connections; it can only bethe time code master. However, you can purchasea synchronizer such as the MOTU DigitalTimepiece that will convert the MIDI Time Codeinternal to the computer into ADAT Sync.

To use these products, first connect the MTCoutput of the sequencer to the MTC input of yoursynchronizer, then connect the synchronizer’sADAT Sync output to the HD24’s ADAT SyncInput. Ask your Alesis dealer about other ADAT-compatible synchronizer options.

You can control the HD24 from a MIDIsequencer using MIDI Machine Control,which sends it commands (REW, PLAY,STOP etc.), but once the command isreceived, the sequencer slaves to the MTCgenerated by the HD24.

SMPTE Time CodeThe HD24 has no built- in SMPTESynchronization, however solutions exist forconverting SMPTE to ADAT Sync. The AlesisBRC and the MOTU Digital Timepiece are onlytwo of the many products that convert a SMPTEinput to ADAT Sync output.

To use these products, first connect the SMPTEoutput to the SMPTE input of your synchronizer,and then connect the ADAT Sync output to theHD24’s ADAT Sync Input. Ask your Alesisdealer about other ADAT-compatiblesynchronizer options.

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MIDIThe HD24’s MIDI jacks are used forsynchronization, software updates, and machinecontrol. Press the MIDI button on the HD24’s frontpanel to scroll between the MIDI function pages.You can also hold the MIDI button down and pressthe YES ( ) or NO ( ) buttons to quickly scrollthrough the pages.

A list of these pages follows with explanations.

Send MMC


Send MMC? N o

When this setting is enabled, the HD24 will send aMIDI Machine Control message each time one ofthe transport keys or Record Enable buttons ispressed.

MIDI Time Code Generation


Generate MTC? N o

To generate MIDI Time Code, set this control to“Yes”. When you press PLAY on the HD24, it willgenerate MTC to match the timecode in the display.This is useful for synchronizing a MIDI sequenceror lighting controller to the HD24. To change thestart time of the MTC generation, you need to editthe Locate 0 point. See page 44 for instructions onhow to edit the point.

Load Software


Load Code? Y /N

If you need to update the software of your HD24via MIDI, this is the page you need to use.

Send Software


Send Code? Y /N

This page allows you to send the software from oneHD24 to another through the MIDI jack. When youpress the YES () button, the HD24’s display willread:

Send Out OS Code

Are You Sure? Y /N

Press the YES () button one more time. Thedisplay will read “Sending OS” with a progressbar as it sends the code. This process will takearound 9 minutes via MIDI. You can abort thesoftware send by pressing the STOP button.

Device ID


Device ID:00 0

This page sets the Device ID for MIDI MachineControl messages. This allows individual MIDIcontrol of multiple MMC-compatible devices. Touse this feature, make sure that the HD24 is set tothe same Device ID number as the device sendingMMC commands.

To update the HD24’s operatingsystem software via MIDI:

Note: if you have a computer, it is also possible toupdate the software via Ethernet, which is faster.See Chapter 9 for details.

1. Connect the MIDI output of your computeror other source of the software to the MIDIIN of the HD24.

2. Press the MIDI button until you reach page 3.


Load Code? Y /N

3. Press the YES ( ) button. The display willread:



4. Press the YES () button. The HD24’s displaywill read:

Waiting for


5. Start sending software from the source device(computer, HD24, etc.). This process takesaround 9 minutes over MIDI.

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Using the HD24 with tape-basedADATs

The ADAT Sync jacks on the back of the HD24 aredesigned to allow easy hookup with previousgenerations of ADAT that used S-VHS tape as theirmedia: the original “black” ADAT, the ADAT XT,XT20, LX20, and the M20, as well as other devicesthat have the ADAT Sync interface such as the BRCMaster Remote Control and computer interfacecards. In very general terms, the HD24 tries toemulate the functionality of an ADAT XT, XT20 orLX20, but there are some obvious differences thatyou need to remember:

• the HD24 has three times as many tracks as atape-based ADAT

• the HD24 has no rewind or fast forward time;locates happen immediately

• the HD24 has features such as Cut, Copy, andPaste that previous ADATs did not have

• on the HD24, each Song exists alone; it doesn’tcontinue playing on to the next song as a tapewould.

Synchronizing with ADATIn most cases, it is best in a tape/HD system tomake the tape-based ADATs the master byputting them first in the sync chain. Otherwise,with the HD24 as master, it will flash back to alocation point and start playing before the tape-based ADATs have finished rewinding.

When the HD24 is the slave, keep in mind that onthe HD24, each song emulates a short tape. Forany given song, the HD24 can only locate totimecode for that song. This can be problematicsince a tape-based ADAT can request the HD24to locate beyond its limits (either too early or toolate in ADAT time). The following should benoted:

• The HD24 requires that its song be at least 10seconds long for it to sync as a slave.Therefore, you must press NEW SONG andrecord some blank time before attempting tosynchronize.

• If a tape-based ADAT stops just past the endof a song, it's very likely that the tape ADATwill try and locate the HD24 past the end ofits defined area. The HD24 will report"Location Out of Range", which is expected.

• On the HD24, if there is "No Drive Selected"or there are "No Songs on Disk", then theHD24 will report “No Tape” to the rest of theADAT chain.

• While a master tape ADAT is unthreaded andfast winding, the HD24 lights theFFWD/REW lights and its timecode displaywill not change until the master stops itsFFWD/REW operation and issues a locatecommand.

• Scrubbing: When the HD24 scrubs audioas a master, Slave units will not follow untilscrubbing is complete. When scrubbing iscomplete, attached slaves will be sent a locatecommand to position themselves to thetimecode of the HD24.

• Format command: On the HD24, Formatand Eject are not supported through the SyncIn or Sync Out ports. A format of an HD24Master, will not format hard drives on slaveHD24 units, nor will it format the tapes ontape-based ADAT slaves. Likewise, a formatof a tape on a Master tape ADAT will notformat a slave HD24 hard drive.

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Using the ADAT HD24 with theBRC Master Remote Control

The BRC Master Remote Control has been thestandard for controlling multi-ADAT systems sinceits introduction. It can control multiple transports,arm up to 128 tracks in a system, receive andgenerate SMPTE time code, and slave an ADATsystem to time code, video, and word clock.However, certain features of the BRC arespecifically designed for the original ADATs, andthe BRC is unable to control certain features ofType II ADATs and the HD24. Keep the followingin mind:

Matching start times forsynchronizationRemember that, unless you change it, each Song inthe ADAT HD24 starts at the 00:00:00:00 time codepoint. So, if the particular section of tape you wantto control also starts at 00:00, you’re all set for theADATs and the HD24 to synchronize. If not, you’llneed to create an offset, a new time reference so theSong Start time of the HD25 matches the locationwhere the song starts on the ADAT tapes.

Create a new Song Start reference on the HD24by changing the value of Location 00 “Start”in the current Song by pressing LOCATESELECT and following the instructions on page44 for editing a locate point.

Do not use the BRC’s TAPE OFFSETfeature to create the offset betweenthe HD24 and the ADATs unless you apply aBRC offset to the tape machines, not to the HD24.(The HD24 appears to the BRC as three differentmachines, but these cannot be offset from eachother for obvious reasons.)

Compatibility issuesDigital routingThe original ADAT system allowed copy-and-paste editing between different ADATs undercontrol of the BRC. To do this, it recommendedthat you connect the OPTICAL OUT of each ADATto the OPTICAL IN of the next. When you pressedthe DIGITAL I/O button on the BRC, and selectedsource tracks from one ADAT, all other ADATsin the system went into Digital Thru mode, wherethe signal from the source was automaticallypassed through each ADAT in the chain, creatingan optical loop. This Digital Routing(Optical Loop) is not supported bythe HD24. In a system combining tape andhard disk, do not connect the ADAT Opticalchain in a loop.

In particular, there is no need to connect theADAT Optical Out of the HD24’s tracks 1-8to the Optical In of Tracks 9-16, etc.because digital copying within the HD24 ishandled more efficiently by the HD24’sinternal Copy and Paste commands.

Arming non-existent tracksFor the purposes of arming tracks, the BRC“sees” an HD24 as being three 8-track ADATs.However, the current Song on the HD24 can be offewer tracks than 24. In this case, the BRC stillassumes that there are 24 tracks available. If theBRC attempts to arm tracks that do not exist forthe current song, the HD24 will not arm theselected tracks; however the BRC will show thosetracks as armed by flashing its REC READYLEDs.

ADAT SyncIn a studio with a BRC, controlling both tapeADATs and HD24s, there are reasons to connectthe tape ADAT(s) first in the sync chain:

• The BRC will listen to the first machine in thechain to check for ready. Here's an example:If you have a BRC->HD24->XT sync chain,bring up a song and play to the end. If youlocate to 0 and press play on the BRC, theHD24 will play almost immediately.However, the XT will not play until it’sfinished locating, which could be manyseconds later.

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• The BRC’s SAVE SETUP TO TAPE and LOAD SETUPFROM TAPE commands (which saves the BRC’sinternal data and song setups to the DATAsection at the head of an ADAT tape) are notsupported by the HD24. So, if an HD24 is firstin the Sync chain following the BRC, then theBRC’s song data cannot be saved or restored.

• No “search” command: On a tape-basedADAT, pressing both PLAY+FFWD or PLAY+REWwill put the ADAT into "Search" mode. Thismode is not supported by the HD24. TheHD24 will wait until the tape ADAT hascompleted its search and locate to the newtimecode once the Locate command is sent.

• No pre or post roll outside Songboundaries: On the HD24, Pre-Roll andPost-Roll are only supported if you havesufficient time in the song. That is, the pre-rollvalue cannot access points before sample 0, andthe post-roll value cannot go past the lastsample of the song.

If you require Pre-Roll and Post-Roll, create a newSong in the HD24 that contains the requiredadditional time, and copy/paste the old song in themiddle of the new song.

Other issues• No punching in on track buttons:

In a tape/HD system controlled by a BRC, iftracks are armed on the tape but not on theHD24, punching in on the BRC will put theHD24 in Record Pending mode (Record LEDflashing). Once in Record Pend, the HD24cannot dynamically arm tracks, nor can itextend the song length. You must arm tracksbefore entering RECORD on the BRC.

• High sampling rates: The BRC cannotcontrol an HD24 if the current Song is at the88.2 or 96 kHz sampling rate. The BRC isdesigned for 48 kHz operation primarily(although you can use the BRC’s PITCHcontrols to reach a 44.1 kHz sampling rate).

• Songs are separate: The BRC’s SETSONG command cannot select different Songson the HD24’s hard drive. (For one thing, theBRC has only 20 songs in memory, while theHD24 may have up to 64.) Nor can the BRCissue NEW SONG or DEL SONG commands to theHD24.

• Location points separate: While boththe HD24 and the BRC have 20 standard locatepoints, they will not be the same. The BRC’s

location points and names are in the BRC’smemory, and the HD24’s are in its memory.The only exception is that, once you performa punch-in from the BRC, the punch-in andout locations (L21 and L22) of both the BRCand the HD24 will be updated to the samevalues.

• Pressing All-Safe on the BRC very fast willsometimes miss a bank of track enables onthe HD24.

• Auto Return display: Setting Loopmode on the BRC will not engage the HD24’sAuto Return feature, only Auto Play.However, this is only a display issue, as theBRC handles the looping functionality.

• Track Delay, not advance: TheBRC’s TRACK DELAY feature can control theHD24’s track delay feature, but only in onedirection: it can delay a track up to 170 ms.,but can’t advance them (since tape-basedADATs were not capable of that).

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Using the HD24 with the M20The M20 and its remote control, the CADI, have themost advanced synchronization capabilities of anyADAT product. The M20 is designed to meet theneeds of video and film post production, includingSMPTE synchronization at 44.1 and 48 kHzsampling rates including pull-up and pull-downfor film transfer capabilities. Although the M20 hasa much faster transport than other ADATs, it stillneeds to be the master of the HD24 for reasonsalready covered.

Note the following if you slave an HD24 to an M20system:

• Jog/shuttle wheel: When you turn thejog wheel on the M20 or CADI the HD24 willnot respond until a locate command is receivedvia the Sync In. It will not “scrub”, althoughthe M20 will (if an Aux track has been created).

• Individual track input mode: Onlythe M20 can place individual tracks into inputmode while leaving the rest untouched.Pressing the white track input keys on a CADIthat correspond to HD24 tracks will have noeffect.

• No ALL SAFE: Pressing ALL SAFE on theCADI will NOT take tracks on the HD24 out ofrecord-ready mode.

• 88.2/96k sampling rates: T h eM20/CADI cannot synchronize an HD24 thatis using the high sampling rates.

• Force Master: It is possible to have notape in the M20 and leave it offline, using itonly as a synchronizer for the HD24. See theM20 documentation for information on the“force master” feature.

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Using EthernetWhen you'd use Ethernet and theHD24

Ethernet is a method for connecting multiplecomputers and peripherals (such as printers anddisk arrays) in a network. Most offices tie theircomputers together in a network so they can sharefiles and software between them, and all print to acentral, shared printer. This is referred to as aLocal Area Network, or LAN.

The largest network of all is the Internet. When acomputer is connected to the Internet (either by atelephone modem or through its local network) itcan contact and share files with millions of othercomputers worldwide.

The ADAT HD24 uses Ethernet technology to shareits audio files with either a single computer, acomputer network, or even the Internet. Since thistechnology is widely available and inexpensive,almost every currently-available computer canconnect to the HD24 with a minimum of hassle.

What you can doWhen you have the HD24 properly connected to acomputer you can:

• Export tracks as standard AIFF or .WAVfiles to a personal computer for editing,mixdown or playback

• Import tracks from a computer forplayback from the HD24

• Set an Internet address in the HD24, alongwith a password, so that anyone in theworld with Internet access who knows theaddress of your HD24 and its passwordcan download audio and work on itelsewhere

• Update the operating system of the HD24itself

LimitationsNote that using the HD24 as a network applianceis different from attaching it to other ADATs or acomputer card such as the ADAT/EDIT systemvia the SYNC and OPTICAL jacks. When theHD24 is in FTP Server Mode, it cannot record orplay back audio; it's busy being a network serverinstead of being a multitrack audio recorder.

Ethernet is not the fastest way to transfer audio.For example, even with a direct connection andfast software, it may take 16 minutes to transfer a4-minute, 24-track song. If you're transferringover the Internet, it may take much longer,depending upon the speed of your connectionand network demands. So, if speed is a concern,using the Optical ports is faster. If you haveseveral HD24s in different rooms of a studio,transferring audio by simply pulling out the harddrive caddy and copying the disk is even fasterthan that.

Having said that, once you have the connectionset up and know how to use it, transfers can takeplace without your having to be present, whileyou're not using your studio. If you share trackswith a studio in another city, you can leave theADAT HD24 in FTP server mode overnight whilethe other studio uploads or downloads.

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Materials you will needFirst, you need the hardware and cabling toconnect your ADAT HD24 via Ethernet. Yourcomputer may also need additional hardware andsoftware.

The HD24's Ethernet connection is designed to beused with 10Base-T systems, since these arethe type most commonly available. If yourcomputer card or network is 100Base-T only,speak to your system administrator orcomputer dealer to obtain hardware withdual 10/100Base-T capability.

CablesEthernet cables are commonly available. Theconnectors look like oversized modular telephonejacks, and are called "RJ-45" connectors. The cablesare often referred to as "twisted-pair CAT 5" cables,(although technically, CAT-3 cables would alsowork for the HD24).

If you are connecting to a singlecomputer without an Ethernet hub in-between, you will need to use a special type ofEthernet cable called a "crossover cable". Note thatnothing else can be on the Ethernet system in thiscase.

Here is a chart showing how the pins of one end ofthe cable are connected to the other:

PC To Hub orHD24 to Hub


PC to HD24 Wiring(crossover cable)

1 ---- 12 ---- 23 ---- 36 ---- 6

1 ---- 32 ---- 63 ---- 16 ---- 2

HubAn Ethernet hub is a special computer peripheralthat allows multiple devices to be on the network.If your computer network already exists, youalready have a hub. But if you're building anetwork for the first time and want to connectmultiple computers, printers, a high-speed modemetc., these hubs are readily available from computersuppliers. Just make sure that it supports 10Base-Tinterfaces.

Interface cardCheck to see if your computer already has a built-in Ethernet interface (most Apple Macintoshesdo). If not, you will need to obtain a card thatplugs into an empty PCI slot on your desktopcomputer, or a PC Card slot on a laptop.

SoftwareIf your computer can connect to the Internet, italready has browser software that will allow it toconnect to the HD24. The two most popular Webbrowsers, both available for free, are Microsoft'sInternet Explorer and Netscape's Navigator. Oneor both of these browsers is bundled with mostcomputer operating systems. Make sure youhave the latest version, and if not, download anupdated version from either

If you plan to do a lot of downloading, it will beworth your while to get specialized File TransferProtocol (FTP) software. These transfer files morequickly than either of the web browsers can.Here are some popular choices:

For PC:

WSFTPLE is freeware available at:

CuteFTP is available at:

For Macintosh:

Transmit, from Panic Software. Transmit isshareware ($24.95) and can be downloaded andtested for free from this website:

Anarchie is available at

Fetch is one of the originals, and is available viaD a r t m o u t h ' s w e b s i t e

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Setting the IP parameters of theADAT HD24

Before you can connect the ADAT HD24 to acomputer or network using its Ethernet port, youhave to set the IP (Internet Protocol) address andsubnet mask of the HD24 and tell it to start actingas an FTP server instead of as a multitrack recorderfor a while. All of these functions are found underthe UTILITY button on the front panel of the ADATHD24.

To set the HD24's address:

1. Press the UTILITY button until the top line of thedisplay reads:

Util06:IP Addr

2. Use the arrow keys under the display to placethe cursor under the number you want tochange. Then press the YES () or NO () keysto change the number.

If your existing network already requires aspecific number (obtained from your networkadministrator), use it. If not, use the default werecommend:

Util06:IP Addr

19 2 .168.001.100

Later we’ll explain how to set the IP address ofyour computer to so it cancommunicate with this address. But as aquick reference, here are the settings for boththe HD24 and your computer that werecommend unless you’re on a morecomplicated network:

HD24 IP Address:

HD24 Subnet Mask:

HD24 Gateway:

PC IP Address:

PC Subnet Mask:

3. Press the UTILITY button again to display thenext page:

Util07:Subnet Mk

25 5 .255.255.000

In most cases this setting should be left asshown above. In large networks, it may bechanged to (Only under veryspecialized circumstances will any number beanything except a 255 or a zero.)

4. Press the UTILITY button again to display thenext page:


00 0 .000.000.000

In most cases this setting should be left asshown above. If you intend to use yourHD24 on the Internet, you will need to setthis address. Please consult your networkadministrator or Internet Service Provider.

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To set the HD24's password:

1. Press the UTILITY button until the display reads:

Util09:FTP Login

U ser:"anonymous"

2. If you want to enter a user name, use the arrowkeys under the display to place the cursorunder the letter you want to change. Thenpress the YES () or NO () keys to change theletter.

If not, remember to enter "anonymous" as your username when the computer asks you for one.

3. To enter a password, use the arrow keys toplace the cursor under the word "User" in thedisplay. Then press the YES () key.

The display will show:

Util09:FTP Login

P ass:" "

Make sure you remember this password for futurereference.

4. Use the cursor keys to enter a password up tonine characters long.

Place the HD24 into FTP servermode:

1. Press the UTILITY button until you see thedisplay:

Util05:FTP Serv

Enable FTP? Y /N

2. Press the YES () key.

The display will show "FTP Server Init"briefly, then show "FTP Server Ready".

The ADAT HD24 is now ready to share files withother devices on the network. See page 88 forinstructions for quitting FTP Server mode.

About setting up your computerOnce the HD24's IP address has been set up, thecomputer needs to be set to a related address onthe network and configured to use Ethernet andTCP/IP as its communication standard.

Doing this is different for the two major types ofoperating system: the Microsoft Windows OSused by (mostly) Intel-based PCs, and the AppleMacintosh OS. While these instructions mayseem complex, in most cases you'll only have todo this once, and then you'll be set.

A word of cautionThese instructions cover the most commonsystem configurations. It's impossible to coverevery possible combination of software andcomputer in this manual. There are dozens ofpreference files, communication settings, etc. thatmay make things a little different from what wedescribe.

If you run into difficulties or something that isn'tcovered in the rest of this chapter, take a note ofevery screen message and setting if they'redifferent from what's shown. More informationregarding networking with your HD24 will beavailable in the support/FAQ area .

To learn more about general networking issues,open the manual for your computer, and checkweb sites such as:

The World of Windows Networking

And finally, nothing works as well as consultingwith someone familiar with networking and yourcomputer's operating system.

If you have an Apple Macintosh computer, turnto the next page.

If you have a Windows-based PC, skipahead to page 80.

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Apple Macintosh configuration instructions

The Apple Macintosh was designed from the outsetto be networked. Most current Macintosh modelshave Ethernet ports built right in; you don't need topurchase additional hardware unless you want tohave several devices on your Ethernet (AppleTalk)network.

Make Ethernet connections to your computerand HD24 only when the power is off toavoid damage.

Read the instructions that came with yourcomputer regarding Ethernet connectionsand operation. Alesis is not responsible fordamage to hardware or software caused byimproper connection or operation.

ConnectionWith the Macintosh (or hub, if applicable)completely shut down, connect either a crossovercable (if you're connecting an HD24 to a singleMacintosh) or a regular cable between the ETHERNETjack on the HD24's rear panel, and the Ethernet jackon the back of the Macintosh (noted with a"<•••>" symbol).

When the connection is properly made andthe computer and HD24 are powered up, agreen LED should light next to the ETHERNETjack on the HD24's rear panel. Once data isbeing transferred, a yellow LED will flashthere as well.

Setting up the AppleTalk, TCP/IPand Remote Access control panelsNext, you have to set up your Macintosh so itknows what language to speak to the ADATHD24. This involves changing several ControlPanel settings within your Macintosh.

Make a note of all these settings before youchange them, so you can go back to theway things were to use your system as itwas previously. Otherwise, you may findthat you're unable to use your printer, orget online to the Internet.

Better yet, use the Location Managerextension to make a copy of all thesesettings so you can easily switch betweenthe mode you use normally, and the modeyou use when exchanging files with theHD24. In the Apple menu, select ControlPanels/Location Manager. In the Filemenu, select Duplicate Location (assumingyou've already set up your current location),then rename it as something like "ADATTransfer". Set the "Current Location" tothat, and follow the following instructions toset AppleTalk properly.

Set Remote Access:

Under some circumstances, you may need tocreate a new "blank" configuration in the RemoteAccess control panel, so your Mac doesn't try touse your Internet service provider to reach theHD24. Simple go to Control Panels/RemoteAccess, duplicate the current setting and renameit (as "HD24"). Then make sure all fields forname, password, and phone number are blank.

An additional benefit of starting here is that theRemoteAccess menu contains links to bothAppleTalk and TCP/IP control panels, which youhave to set next.

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To change the TCP/IP settings:

These instructions assume that your Macintosh isNOT connected already to a network. If you'realready on a network, you may need to followspecial instructions from the person in charge of it.

1. Under the Apple Menu, select ControlPanels, then TCP/IP.

2. In TCP/IP ' s F i l e menu, se lec tConfigurations.

3. Select any configuration, and duplicate it.When it asks you for a name, rename theconfiguration something like "ADAT Transfer".

4. Click on the new duplicate and then on "MakeActive" (or press the Return key).

5. At the top of the TCP/IP screen, change"Connect via:" to Ethernet.

6. Set "Configure" to Manually.

7. Set the IP Address to the number you intend touse for your computer.

We recommend "" if you intend to havea single connection between one Mac and theHD24. If you're connecting to a larger network,you'll have to contact the administrator of yournetwork to get the number for your computer, if itisn't there already. See "More about IP addresses"on page 86.

8. Set the Subnet mask to, or othernumber set by your network administrator.

9. If you're not on a network, erase all other fieldsfor Router address, Name server address,domain name server, etc. Otherwise, leavethem alone.

When you're done, the TCP/IP window shouldlook something like this:

One last step: click on the Options button andclick the Active button to make TCP/IP active.You can also check the "Load only when needed"box, and your web browser will automaticallyturn it on for you.

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To turn on AppleTalk:

To communicate with the ADAT HD24, theMacintosh must be set to use AppleTalk, via theEthernet port. If you're not already doing that:

1. Open up the AppleTalk control panel (Applemenu/Control Panels/AppleTalk).

2. As you did on the TCP/IP control panel, werecommend that you duplicate the currentconfiguration and rename it, so it's easy to goback to your previous settings. (In AppleTalk,select File/Configurations, and duplicate aconfiguration. Then rename it, and make thatconfiguration active by clicking the MakeActive button.)

3. Set "Connect via:" to "Ethernet" at the top of thepage.

If there is no connection to the Ethernet jack of thecomputer, you'll get an error message asking you tohook it up. If you haven't already, connect to theHD24, turn its power on, and set it to FTP Servermode (see page 76).

4. Click on the Options button. A screen comesup to turn AppleTalk on; click on the "Active"radio button and hit "OK".

If the screen doesn't look like the one above, go to theEdit menu and select "User mode…" Then set theUser Mode to "Advanced".

If you're using Apple's Control Strip feature, youcan also turn AppleTalk on and off by clicking on

the icon of the computer in the strip and selecting"AppleTalk Active".

In most cases, you will not set your ownAppleTalk address, so you won't check the "Userdefined" box, or care about the Node andNetwork numbers. If you're in a special situationwith zones, etc., contact the person who set upyour network.

Location manager tip: If you want to beable to switch back and forth betweensettings in the future, open the LocationManager and save a new location with theTCP/IP and AppleTalk configurations youjust set. Check them by selecting each inturn and making sure they're the new ones(i.e., "ADAT HD24" etc., not "Home" or"AOL").

Watch out for extension conflicts: Notethat you may have installed certain systemextensions that may conflict with Ethernetnetworking. For example, the sharewareutility "FreePPP" doesn't allow Apple's coreOpen Transport system to work. If youhave a problem, you might want to restartyour Mac with all extensions off (restartwhile holding the shift key down). If itworks then, use the Extensions Manager toturn individual extensions back on until theproblem reappears…then you know whichone is incompatible.

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Windows 95/98/ME PC configuration instructionsIf you own a PC, you must make sure it has anEthernet port first. If you’ve just purchased a networkcard, then you need to follow the manufacturer’sinstructions for installation. Please complete thenetwork card installation first, then install TCP/IPbefore proceeding, if it isn't already present. If it is,then skip to page 82.

To install the TCP/IP protocol in aWindows 95/98/ME PC:

1. Click the Start button. Choose Settings, thenControl Panel.

2. Double-click the Network icon. Your Networkwindow should pop up. Select the Configurationtab.

3. Click the Add button.

4. Double-click Protocol.

5. Highlight Microsoft under the list ofmanufacturers.

6. Find and double click TCP/IP in the list to theright.

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7. After a few seconds, you will be brought backto the main Network window. The TCP/IPProtocol should now be listed.

8. Click O K . Windows may ask for originalWindows installation files. Supply them asneeded. You may have to find your Windows95/98/ME install CD.

9. Windows will ask you to restart the PC. ClickYes.

TCP/IP Installation is complete. Now, you have toset the IP address of your PC so that it can accessthe IP address of the ADAT HD24.

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To set the IP address of a Windows95/98/ME PC:

1. Click the Start button. Choose Settings, thenControl Panel.

2. Double-click the Network icon. Your Networkwindow should pop up. Select theConfiguration tab.

3. In the Configuration window, select theTCP/IP protocol line that has been associatedwith your network card/adapter. Click theProperties button. If there is no TCP/IP linelisted, please follow the instructions for“Installing the TCP/IP Protocol” on theprevious pages.

4. Choose the IP Address tab. Select "Specify anIP address." For the IP Address use Subnet Mask, use

If you've already set up your network, you willleave these numbers unchanged. Write down the IPaddress of your computer; the first three numbers(and a different last number unique from everythingelse on the network) will be entered into a Utilitypage of the ADAT HD24.

5. Click OK. Windows may ask for originalWindows installation files. Supply them asneeded. You may have to find your Windows95/98/ME install CD.

6. Windows will ask you to restart the PC. ClickYes.

When the connection is properly made andthe computer and HD24 are powered up, agreen LED should light next to the ETHERNETjack on the HD24's rear panel. Once data isbeing transferred, a yellow LED will flashthere as well.

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Verifying a PC's connection to theHD24Now that you have your PC setup to talk to theHD24, shut the computer down and connect the PCto the HD24. You can do this with a hub, ordirectly using a crossover cable. Power up allequipment.

Make Ethernet connections to your computerand HD24 only when the power is off toavoid damage.

Read the instructions that came with yourcomputer regarding Ethernet connectionsand operation. Alesis is not responsible fordamage to hardware or software caused byimproper connection or operation.

To test the connection between aPC and the HD24 using Ping:

1. Click Start, then Run, and type “command”.This will bring up the DOS window.

2. At the DOS Prompt, type “ping”(the address of the HD24). Information similarto the screen below will be displayed:

Now that you've gotten your PC or Macintoshready to communicate, let's move on to actuallytransferring digital audio files between the HD24and the computer via Ethernet and a common Webbrowser.

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Transferring files with ExplorerOnce you're sure that:

• the computer has the correct networksettings

• the HD24's IP address and passwords areset, and

• the HD24 is in FTP server mode

you're ready to launch software in the computerthat can download files from the HD24. Note thatyou can't download audio using the digital audioediting software itself…you have to perform thisintermediate step of downloading audio into afolder first. Then, within your audio software, youplace or import the files into the editing window ofsoftware such as Emagic's Logic Audio,Digidesign's Pro Tools, Steinberg's Cubase orNuendo, MOTU's Digital Performer, or Cakewalk.

As mentioned on page 74, any web browsersoftware can "contact" an ADAT HD24 connectedto it. File transfer software can do this job morequickly, but as an example of how the processworks, the following example uses MicrosoftExplorer software.

To download a Song from theHD24 using Explorer:

1. Launch the browser software.

2. In the address line (URL) of the browser, enter"ftp://" followed by the IP address of theHD24 that you previously set on page 5 of theUtility menu. For example we used:

Hit the RETURN key.

If your computer starts to dial a modem, or if thenext screen doesn't appear in a few seconds, click onthe STOP icon of the browser and recheck thenetwork settings of the computer (see page 76).

3. A pop-up window may appear asking for yourUser ID and password. If so, enter the username and password you entered into theUtility menu of the HD24.

Within a few seconds you should see a screenthat looks like this:

The "Readme" pages are "web pages" built-in tothe HD24, and explain the structure of the files soother people can download and return files tothem.

4. Click on the name of the drive (Drive1, orDrive2, if present).

You'll see a list of the Songs currently on thedrive.

5. Click on the name of the Song you want todownload.

You'll see two folders, one with the name "AIFF"and the other with the name "WAV".

If you want to download all the tracks inthe Song:

6. Click, hold and drag either the AIFF or WAVfolder to your desktop, depending on thetype of file your computer software needs toimport.

Many programs can deal with either file format,but generally speaking, most PCs tend to use.WAV files, and most Apple Macintosh softwareuses AIFF files.

If you want to download only certaintracks of a Song:

6. Click once on either the AIFF or WAV folder.

A screen like this will appear:

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7. Click and hold on an individual track you wantto download. Drag it to the desktop (or to afolder). Tracks must be downloaded one at atime (or see Tip on Using File Helpers, below).

If you simply click on a file, your browser mayattempt to download and open the audio toplay it from within the browser. Simply clickon the STOP icon of Explorer to stop this.

During a download, the display of the HD24 willread:

FTP Transmitting

==== (XX%)

Whether you download an entire Song, orindividual tracks, open Explorer's DownloadManager window from the Tools menu. Thiswill show you the progress as files aredownloaded, and the current transfer speed.When the Download Manager says"Complete" and puts a checkmark next to thetrack name (for individual tracks) or the AIFFor WAV folder (for an entire Song), theprocess is complete and you're ready to usethose files in another audio program.

Tips and tricks about ExplorerTip on using File helpers: If you'rehaving problems with other applications (likeQuickTime) suddenly starting when you're tryingto download files, check Explorer’s File Helperssettings.

1. Pull down Explorer's Edit menu and selectPreferences.

2. Click on "File Helpers", under "ReceivingFiles". (You may have to click on the arrownext to "Receiving" to see this.)

3. Find the file helper for AIFF Sound, (theremay be several…try the one with theextension ".aif", and MIME type audio/x-aiff)and select it. If you're using WAV files, scrolldown the list to that (listed as "WindowsWAVF Sound").

4. Click the "Change" button.

5. At the bottom of the "Edit File Helper"window, where it says "How to Handle", itprobably says "View with Browser". Changethat to "Save To File", and you can click onmultiple AIF files at once to download them.

While you're in the Preferences window, youmay want to check your Download Options sothat you can set the location for the downloadsand set how many happen at once.

"Last Modified": Since the HD24 does nothave a date and time stamping function, all of itsfiles will carry a date of Monday, Jan. 1, 2001,regardless of when they were actually recorded.That's simply a default setting…don't freak out.When you download a file to the computer, itwill be stamped with the current date and time.

About using FTP downloadsoftwareOnce you've gotten your feet wet, be aware thatdownload speeds may be increased many timesby using dedicated FTP software (see page 74).The procedures for most software are similar tothat shown for the browser: simply click on a fileor folder and drag it to the destination.

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To upload files from thecomputer to the HD24

After you have edited audio in the computer, youcan send it back to the HD24, with certainlimitations:

• The file name must follow the format"TrackXX.aif" or "TrackXX.wav",where XX isthe number of the track.

• Files can only be dragged into a folder of thecorrect type (i.e., AIFF or WAV).

• The Song must already exist on the HD24'sdrive, and it must have the same number oftracks. So, if you've created a new song onyour computer, and you wish to transfer it tothe HD24, first create a new song on the HD24using the new song's sample rate and trackwidth first.

• If you have lengthened a file in the computer,the HD24 must lengthen the song before it goesahead and uploads the file. It will do thisautomatically, as long as there is availableempty disk space. If the HD24 doesn't haveenough free space to store the longer song, thefile transfer will be aborted.

To upload, drag the folder or individual files fromthe desktop of the computer into the Web browseror FTP software window, after a connection hasbeen established.

More about IP addressesAn IP address (such as "") is actuallyfour eight-byte numbers used to define a network;that's why each number can only be in the rangefrom 0 to 255. In a network that has up to 256different elements, the first three bytes will be thesame for every piece of equipment on the network,and each equipment will have a unique lastnumber.

Certain numbers are reserved for special uses. Forinstance, IP addresses ending in .0 or.255 are reserved, and should not beused.

The most important thing is that whatever IPaddresses you choose for your system, that theydon't conflict with or infringe upon other networksyou may need to access. We chose the prefix"192.168.1…" as the default because that has beendesignated as a prefix for local networks only.

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About the subnet maskThe subnet mask is a standard parameter used forTCP/IP networking. On the HD24, the subnetmask is used to determine how many computersare on your local network. For instance, if yourHD24 IP address is set to A.B.C.D, and your subnetmask is set to, then you are telling theHD24 to look for any computer from A.B.C.0 toA.B.C.255 on the local network. Similarly, if thesubnet mask is set to, then the HD24will look for any computer from A.B.0.0 toA.B.255.255.

About the gateway addressThe gateway address is used to let the HD24 knowhow to get to another network. By default, thegateway address is set to, which means thatit is disabled. However, if the gateway address isset to a non-zero value, then it can respond toaddresses outside its local network.

Gateway Hint:The gateway address must be part of the localnetwork. For instance, if the HD24 IP address is192.168.1.1, and the HD24 subnet mask is255.255.255.0, then the gateway must be in therange of to

Connecting the HD24 directly toa cable or DSL modem

It is possible to connect the HD24 to the Internetdirectly, but unless your ISP (Internet ServiceProvider) assigns you a permanent, specific IPaddress that your modem will always use, it maybe tricky.

In most cases when your computer connects tothe Internet, its IP address is given to it by thehost computer at the ISP. This is called adynamic address. When you log off, that addressmay be reassigned to a different user.

The HD24 doesn't have the capability of havingits IP address set by the host. It must be setmanually in the Utility pages.

Check with your ISP to find out if they can assignyour modem a static address, which can beentered manually to the ADAT HD24.Otherwise, see page 89.

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To quit FTP server modeOnce your transfers are complete, you must leaveFTP server mode in order to resume normalrecording and playback from the ADAT HD24.

1. Make sure that all downloads are complete andall users have logged off the system.

The ADAT's display should read

FTP Server Ready

2. Press the STOP transport key on the front panel.

The ADAT's display will show

Disable FTP? Y /N

3. Press the YES () cursor key. The unit willreturn to normal operation, and inquiries to theFTP address will go unanswered.

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An Example NetworkThe following network diagram can be used aguide to help you setup your internal network. Inthis scenario, the internal network consists of sevendifferent elements: The Router, the PC, the Mac,three HD24s and the Hub. The Router is assignedthe internal address of Any item onthe internal network (Mac/PC/HD24) that needsto connect to the outside world will send messagesto the Router, a.k.a. the Gateway. All othermessages will be contained to the internal network.Note that each device (except the Hub, which is a"dumb" device) has a unique address on theinternal network.

In this network, the PC or the Mac can connect toany or all of the HD24 machines. Since each HD24has its own unique address, they can co-exist. Infact, a user on the Mac can be working with HD24

#1, while a user on the PC can be working withHD24 #2.

If an outside or Internet-based request comes in,then it is the router’s job to forward the messageto the correct internal IP address. For instance, ifthe Router is configured to send FTP messages to192.168.1.100, then HD24 #1 will available via theInternet.On a side note, if a user from the PC and the Macattempt to access the same machinesimultaneously, then commands will be queuedon a first come, first serve basis. Two commandscannot be handled by a single HD24simultaneously.

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TroubleshootingTroubleshooting Index

If you experience problems while operating your ADAT HD24, please use the following table to locate possiblecauses and solutions before contacting Alesis Product Support for assistance.

Symptom Cause SolutionNo input audio Test with a known good

input.Bad cables Replace the cables.Destination is turneddown

Check the connectionsand the level of the mixeror amp that the ADATHD24 is connected to.

No audio from outputs

Track width is restricted(i.e., when the Song isdefined as a 12-tracksong, there is no outputfrom tracks 13-24)

Copy all tracks, and pasteinto a new song definedas having more tracks.

Trying to record onto atrack higher than thecurrent Song allows

Copy all tracks, and pasteinto a new song definedas having more tracks.

INPUT SELECT is set to2, 4, 8 or 12- input mode

Reset INPUT SELECT for24 input mode

No audio input or outputon certain channels

EDIT PREVIEW playsback only tracksselected for editing

To hear all tracks, de-select any tracks armedfor editing using TRACKEDIT.

Power is not connected Time for a coffee break.No powerRear panel powerswitch is off

Turn it on; (STOP LEDwill always remain lit)

No power (STOP LEDwon't go on when rearpanel power switch is on).

Blown fuse Correct any problem thatmay have caused the fuseto blow, and replace thefuse with the proper type.

Cables are crossing apower cable

Make sure that the ADATHD24 and its audio cablesare kept away from powercables, other powertransformers and wallwarts.

Bad cables Replace the cable with anew, high-quality cable.

Buzz from outputs

Problem with the source Try bypassing the ADATHD24 by connecting theinput cables to the outputcables and see if theproblem remains.

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Symptom Cause SolutionEmpty caddy Install an IDE drive in the

caddyDrive improperlyinserted

Remove the drive andreinsert, firmly pushingon the edges of the handle

Foreign material indrive socket

Power down unit, and trycaddy in other drive bay

Drive is in slave mode Remove drive from caddyand change jumper from“slave” to “master” or“single” mode

Drive file system wascorrupted by installingthe drive in a computer

Use Utility 3 to scan diskfor errors and recoverdata

Drive will not mount

Connectors in caddyloose

Open the drive caddy andre-attach connectors

“Blips” are heard at theedit points after pastingaudio

Several PASTEoperations at the samepoints

Use PASTE UNDO whendoing repetitive editing.See page 64.

Noise induced inunbalanced lines

Use only balancedconnections in the studio

AC hum

Ground differencestraveling through cables

Place all equipment in thestudio on a commonground (see next page)

Cannot select ANALOGinput

Song is initialized at88.2 or 96 k sample rate

Obtain 96k Analog boardto record at high rates, oruse a 44.1/48k song.

Song shows incorrect dataon screen

Errors on hard drive Use Utility 3 to scan diskfor errors and recoverdata

HD24 will notsynchronize to SYNC IN

Song is less than 10seconds long

Record at least 10 secondsin a song beforesynchronizing

Cannot find any spoon There is no spoon

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Avoiding ground loop noiseIn today’s studio, where it seems every piece ofequipment has its own computer chip inside, thereare many opportunities for ground loop problemsto occur. These show up as hums, buzzes orsometimes radio reception and can occur if a pieceof equipment “sees” two or more different paths toground. While there are methods to virtuallyeliminate ground loops and stray radio frequencyinterference, most of the professional methods areexpensive and involve installing a separate powersource just for the sound system. Alternatively,here are some helpful hints that professional studioinstallers use to keep those stray hums and buzzesto a minimum.


Most stray hums and buzzes happen as a result ofdifferent parts of the sound system being pluggedinto outlets of different AC circuits. If any noisegenerating devices such as air conditioners,refrigerators, neon lights, etc., are already pluggedinto one of these circuits, you then have a perfectcondition for stray buzzes. Since most electronicdevices of a sound system don’t require a lot ofcurrent (except for power amplifiers), it’s usuallysafe to run a multi-outlet box or two from aSINGLE wall outlet and plug in all of thecomponents of your system there.


Many hums come from audio cabling being toonear AC wiring. If a hum occurs, try moving theaudio wiring around to see if the hum ceases ordiminishes. If it’s not possible to separate the audioand AC wiring in some instances, make sure thatthe audio wires don’t run parallel to any AC wire(they should only cross at right angles, if possible).


A) Disconnect the power from all outboarddevices and tape machines except for theADAT HD24, the mixer and control roommonitor power amp.

B) Plug in each tape machine and outboard effectsdevice one at a time. If possible, flip thepolarity of the plug of each device (turn it

around in the socket) until the quietestposition is found.

C) Make sure that all of the audio cables are ingood working order. Cables with a detachedground wire will cause a very loud hum!!

D) Keep all cables as short as possible, especiallyin unbalanced circuits.

If the basic experiments don’t uncover the sourceof the problem, consult your dealer or techniciantrained in proper studio grounding techniques. Insome cases, a “star grounding” scheme must beused, with the mixer at the center of the starproviding the shield ground on telescopingshields, which do NOT connect to the chassisground of other equipment in the system.

Line Conditioners and ProtectorsAlthough the HD24 is designed to tolerate typicalvoltage variations, in today’s world the voltagecoming from the AC line may contain spikes ortransients. These can cause audible noises, andthey can stress your gear and, over time, possiblycause a failure. There are three main ways toprotect against this, listed in ascending order ofcost and complexity:

• Line spike/surge protectors. Relativelyinexpensive, these are designed to protectagainst strong surges and spikes, actingsomewhat like fuses in that they need to bereplaced if they’ve been hit by an extremelystrong spike.

• Line filters. These generally combinespike/surge protection with filters thatremove some line noise (dimmer hash,transients from other appliances, etc.). Agood example is the Isobar™ series fromTripp Lite.

• Uninterruptible power supply (UPS). This isthe most sophisticated option. A UPSprovides power even if the AC power linefails completely. Intended for computerapplications, a UPS allows you to completean orderly shutdown of a computer system inthe event of a power outage. In addition, theisolation it provides from the power lineminimizes all forms of interference—spikes,noise, etc.

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Care and MaintenanceCleaningDisconnect the AC cord, then use a damp cloth toclean the ADAT HD24’s metal and plastic surfaces.For heavy dirt, use a non-abrasive householdcleaner such as Formula 409™ or Fantastik™. DONOT SPRAY THE CLEANER DIRECTLY ONTOTHE FRONT OF THE UNIT AS IT MAY DESTROYTHE LUBRICANTS USED IN THE SWITCHESAND CONTROLS! Spray onto a cloth, then usecloth to clean the unit.

Refer All Servicing to AlesisWe believe that the ADAT HD24 is one of the bestmultitrack recorders that can be made usingcurrent technology, and should provide years oftrouble-free use. However, should problems occur,DO NOT attempt to service the unit yourself unlessyou have training and experience. Service on thisproduct should be performed only by qualifiedtechnicians. NO USER-SERVICEABLE PARTSINSIDE.

The unit must be totally disconnected from allsources of AC power before the unit isopened. HAZARDOUS VOLTAGES EXISTWITHIN THE CHASSIS THAT MAY BE FATAL..HAVE THE UNIT PROFESSIONALLY SERVICEDif needed!

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Obtaining Repair ServiceBefore contacting Alesis, check over all yourconnections, and make sure you’ve read themanual.

Customers in the USA and Canada: If the problempersists, call Alesis USA at 1-800-5-ALESIS andrequest the Product Support department. Makesure you have the unit’s serial number with you.Talk the problem over with one of our technicians;if necessary, you will be given a return order (RO)number and instructions on how and where toreturn the unit. All units must be shipped prepaidand COD shipments will not be accepted.

For prompt service, indicate the RO number on theshipping label. Units without an RO will not beaccepted. If you do not have the original packing,wrap the unit in a plastic bag and ship it in a sturdycarton, with shock-absorbing materials such asStyrofoam pellets (the kind without CFCs, please)or “bubble-pack” surrounding the unit. Shippingdamage caused by inadequate packing is notcovered by the Alesis warranty.

Tape a note to the top of the unit describing theproblem, include your name and a phone numberwhere Alesis can contact you if necessary, as wellas instructions on where you want the productreturned. Alesis will pay for standard one-wayshipping back to you on any repair covered underthe terms of this warranty. Next day service isavailable for a surcharge. Field repairs are notauthorized during the warranty period, and repairattempts by unqualified personnel may invalidatethe warranty.

Customers outside the USA and Canada:Contact your local Alesis distributor for anywarranty assistance. The Alesis LimitedWarranty applies only to products sold to usersin the USA and Canada. Customers outside ofthe USA and Canada are not covered by thisLimited Warranty and may or may not becovered by an independent distributor warrantyin the country of sale. Do not return products tothe factory unless you have been given specificinstructions to do so.

Internet Address: Important information andadvice is available on our web site:

Email may be addressed to:

[email protected]

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SpecificationsAUDIO INPUT

Input Connectors: 24 Balanced 1/4" TRS jacksNominal Input Level: +4 dBu (1.23 VRMS) = -15 dBFSMaximum Input Level: +19 dBu (6.9 VRMS) = -0 dBFSInput impedance: 10 kΩ

AUDIO OUTPUTOutput Connectors: 24 Pseudo-Balanced 1/4" TRS jacksNominal Output Level: +4 dBu (1.23 VRMS) = -15 dBFSMaximum Output Level: +19 dBu (6.9 VRMS) = -0 dBFSOutput impedance: 220 Ω

AUDIO PERFORMANCESignal to Noise Ratio: 103 dB A-Weighted, Analog In to Analog OutTHD+N: < 0.003%, Analog In to Analog OutFrequency Response: 22-22 kHz ±0.50 dB, Analog In to Analog OutPower consumption: 60 Watts Max (100-240 VAC / 50-60 Hz)

20 Watts Max in Stand-By Mode

MECHANICALSize: 5.24" H x 19.0" W x 13.5" D

133mm H x 483mm W x 342mm DRack spaces: 3 spacesWeight: 21 lbs (9.6 kg)

All measurements done over a 22 Hz - 22 kHz range with 1 kHz sine wave at 18dBu (-1dBFS) input. Impedancesare measured at 1 kHz.

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Dimensional drawing

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Index16-bit, 2520-bit, 2588.2 kHz, 6596 kHz, 6596kHz converter board option, 66AC power

and noise, 93ADAT, 24

synchronization with, 69ADAT FST™, 3ADAT Optical, 25, 70

and 96 kHz, 66ADAT Sync, 17, 39, 70AIFF files, 73ALL INPUT, 39ALL INPUT button, 40ANALOG, 39audio cables, 23AUTO INPUT button, 40Auto Play, 45Auto record, 47Auto Return, 45, 71backup drive, 54BRC, 70CD, 33CLIP, 37Clock Source, 39Compact Disc, 65computer

connected via Ethernet, 73Connections, 21COPY, 15, 55, 58

song, 54crossfade regions, 64CURSOR, 15CUT, 15, 55, 58DB 9, 24DEL SONG, 33DIGITAL, 39digital input, 39Digital routing, 70drive

dismounting, 50drive

about, 31info, 53installation in caddy, 53

scanning for errors, 52Drive button, 49Edit End, 55Edit Start, 55Error messages

LoopStart > LoopEnd, 46PunchIn>PunchOut, 47

Ethernet, 73cables, 74hub, 74

Explorer, 84FCC Information, 10FFWD, 35file transfer, 4, 73footswitches


Formatin ADAT system, 69

format drives, 49Formatting disks, 51FTP Server Mode, 73, 76

quitting, 88FTP software, 74fuse, 91Ground Loops, 93grounding, 7, 20HD FREE SPACE indicator, 16,


analog, 22digital, 25

Input Modes, 22input normalling, 22, 39INPUT SELECT, 39Internal, 39Internet, 73Invalid Format, 49IP Address, 75LOCATE, 35, 43LOCATE 0, 34, 43LOCATE SELECT, 70Location points, 71loop, 45Loop Start and End, 46LRC remote, 29M20, 72

Macintosh, 77Maintenance, 94media cost chart, 5meters, 36, 37MIDI, 68MIDI time code, 43, 68Mixer

hookup, 22Mounting, 49Name, 33network, 89New Song, 13, 32noise, 93offset, 70optical cables, 25outputs

analog, 21password, 76PASTE, 15, 55, 60

between songs, 61PASTE UNDO, 64Peak Clear, 37PEAK MODE, 38Pitch, 42PLAY, 35play, 41Power, 20Power cable, 7Power switch, 17Pre-Roll and Post-Roll, 71punching in, 35rack mounting, 19RECORD, 35RECORD ENABLE buttons, 36Recording, 35recording level, 38recording time, 51

at high sample rates, 65REW, 35Router, 89Safety, 7sample rate, 32, 33, 35

and location points, 43compatibility in PASTE

operations, 61compatibility w. BRC, 71high (88.2 & 96 kHz), 65

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scan, 41scrub, 35

for edit points, 57scrubbing, 41, 69

from M20/CADI, 72selecting drives, 49SET LOCATE, 44, 55shock, 7slave, 69SMPTE time code, 70, 72Snakes, 21software

updating code, 68SONG SEL, 32Songs, 31Specifications, 97STOP, 35SYNC, 24synchronization, 70

by redefining Locate 0, 34TIME counter, 34Track Delay, 71Track Edit, 55, 58, 59Track Slip, 63tracks

setting number of, 32transport, 34UNDO, 15, 55, 62user name, 76Utility, 63Voltage conversion, 20WAV files, 73Windows, 80WORD CLOCK IN, 17WORD IN jack, 39XLR

to TRS adapter, 21

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Alesis Limited WarrantyALESIS CORPORATION ("ALESIS") warrants this product to be free of defects in material and workmanship for a

period of one (1) year for parts and for a period of one (1) year for labor from the date of original retail purchase. Thiswarranty is enforceable only by the original retail purchaser and cannot be transferred or assigned.

The purchaser should complete and return the enclosed warranty card within 14 days of purchase.

During the warranty period ALESIS shall, at its sole and absolute option, either repair or replace free of charge anyproduct that proves to be defective on inspection by ALESIS or its authorized service representative. In all cases disputesconcerning this warranty shall be resolved as prescribed by law.

To obtain warranty service, the purchaser must first call or write ALESIS at the address and telephone numberprinted below to obtain a Return Authorization Number and instructions concerning where to return the unit for service.All inquiries must be accompanied by a description of the problem. All authorized returns must be sent to ALESIS or anauthorized ALESIS repair facility postage prepaid, insured and properly packaged. Proof of purchase must be presented inthe form of a bill of sale, canceled check or some other positive proof that the product is within the warranty period.ALESIS reserves the right to update any unit returned for repair. ALESIS reserves the right to change or improve design ofthe product at any time without prior notice.

This warranty does not cover claims for damage due to abuse, neglect, alteration or attempted repair byunauthorized personnel, and is limited to failures arising during normal use that are due to defects in material orworkmanship in the product.



THIS CONTRACT SHALL BE GOVERNED BY THE INTERNAL LAWS OF THE STATE OF CALIFORNIAWITHOUT REFERENCE TO CONFLICTS OF LAWS. This warranty gives you specific legal rights, and you may also haveother rights required by law which vary from state to state.

This warranty only applies to products sold to purchasers in the United States of America or Canada. The terms ofthis warranty and any obligations of Alesis under this warranty shall apply only within the country of sale. Withoutlimiting the foregoing, repairs under this warranty shall be made only by a duly authorized Alesis service representative inthe country of sale. For warranty information in all other countries please refer to your local distributor.


12509 Beatrice Street

Los Angeles, CA 90066



for more effective service and product update notices

© 2001 Alesis Corporation Specifications Subject To Change Without Notice

7-51-0096 8/01