adat hd24 manual 1 - virginia tech...introduction/safety instructions adat hd24 reference manual 3...

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

Rehearsing..............................................48

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

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

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.



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.



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)

SONIC PERFORMANCE:

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

COMPARING MEDIA COST @48kHz:

Recording CostMEDIAUNITPRICE

Recordingtime permedia unit

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

Per trackminute

Per 24-trackminute

Perproject

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



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.


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.



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.



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.



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:

www.alesis.com

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.

chapter 1


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.

quick start guide • chapter 1


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.

chapter 1 • quick start guide


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 >).



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.

Drivecaddies:

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.



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.



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.



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”). SeeChapter 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. SeeChapter 8: Synchronization and MIDIand Chapter 2: Connections.

chapter 2


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.

connections • chapter 2


Power

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.

chapter 2 • connections


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:

AAAAAAAAAAAA

Tip

Sleeve

Signal

Ground

Tip

Sleeve

Unbalanced Line Input

AAAAAAAAA

Tip

Sleeve

Hot

Ground

Tip

Sleeve

Balanced Line Input

Ring

Ring

Cold

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.



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).



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:

Example:

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



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.



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".



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.



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.



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.



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".

chapter 3


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.

basic recording and playback • chapter 3


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

chapter 3 • basic recording and playback


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.



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 FThe 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.



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.



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”.



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.



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):

Momentary

Peak Hold

Continuous

Peak Hold

No

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 ma

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