Modular recording. This is the feature that makes ADAT and the ADAT System perhaps the most flexible multitrack recorder ever designed. Because ADAT's SVHS tape format is so inexpensive, you can easily record alternate versions of vocals, solos, background accompaniments; whatever your creative urge dictates. Modular recording means you can build as many tracks as you desire while you're recording and do composite editing with the BRC and ADAT's Optical Digital Interface (see next section) before the final mixdown.
Optical digital interface. In addition to conventional analog inputs and outputs, a master digital I/O carries all eight tracks simultaneously via optical cable, allowing for perfect, degradation-free digital dubbing between ADATs. And with the addition of the optional BRC Remote Control, you can assign any part of any track to any other track in a multiple ADAT system. This means you can do complex composite editing. Like the chorus on track 2? Want to replace the chorus on track 15? Easy to do with the BRC carrying the timing and Sync
Information while the optical cable carries all the digital audio. The new chorus on track 15 will be an exact digital duplicate of the one on track 2. Feel particularly inspired one day, but can't make up your mind about which lead solo to go with? Fill five or six tracks of a single S-VHS cassette tape with your hottest playing. Take the best performance, or the best parts of each one and recompose the entire solo on a new track. All in perfect sync, all sample accurate, all in the digital domain. The popular recording practice of composite vocals is just as easy, and more effective than ever with ADAT to support your efforts.
AI-1 AES/EBU and S/PDIF Digital Interface with Sample Rate Converter. If you need to integrate your ADAT recordings with digital recording equipment from other manufacturers, an optional accessory box, the Alesis AI-1, can isolate the digital audio signal 2 tracks at a time from the optical interface's 8-track data stream, and assign that pair to the industry standard AES/EBU and S/PDIF interfaces. This allows for direct digital connection, with sample rate conversion, to and from other digital audio recorders, DAT recorders, CDs, hard disk recorders, synthesizers, and more. LRC Remote Control. Each ADAT is supplied with the LRC Remote. This handy device duplicates ADAT's front panel play, record, fast forward, rewind, stop and 3 point autolocate system. You can also control the monitor select functions. Highly sophisticated and comprehensive optional BRC Master Remote Control. The BRC is the brains of the ADAT System. It supplies sophisticated synchronization and overdubbing functions for multiple ADAT machines, remote control of virtually all recorder functions, reads and generates SMPTE time code, and generates MIDI Time Code (MTC) and MIDI clocks. The BRC can control up to 16 ADATs for a total of 128 tracks of digital audio. RMB Remote Meter bridge option. When using the BRC in a multi-ADAT system the RMB Remote Meter Bridge provides localized viewing of 32 channels of LED meters. It's designed to mount on top of the BRC (or be rack mounted) so that you can install your ADATs in a remote rack and control functions and view critical metering of the recorders directly from one location. Easy interfacing with professional, project and home studios. ADAT includes a balanced 56 pin ELCO connector for +4dBu interfacing, typical in professional studios. For the home and project studio using -10 signals, ADAT includes unbalanced -10dBV inputs and outputs on 1/4" jacks. For convenience, the balanced and unbalanced inputs and outputs work simultaneously. Voltage-tolerant power supply. ADAT accepts any AC voltage between 90 and 250 volts, without the need for external converters. Compatibility with multi-channel mixdown formats. ADAT is ideal for quadraphonic, surround, and theatrical sound applications that require more than two channels for the final master.

For more information on digital recording, see Appendix 1. Appendix 2 is a glossary of digital recording-related terms that may be helpful as you read this manual.
IMPORTANT NOTE ABOUT THIS MANUAL
ADATs transparent user interface may tempt you to just plug in and start recording. We can certainly understand your excitement, but please at least do the following:
Read section 1.4 on the difference between engaged and disengaged tapes, and section 3.1 on formatting tapes (with multiple ADAT systems, also refer to section 5.2). These important sections describe recording concepts that have no counterpart with analog recorders, and which must be understood before you start using ADAT. Please read the entire manual at some point to acquaint yourself with the many ADAT features that youll know about only if you read the manual.
OVERVIEW OF MAIN FUNCTIONS
Here is a brief rundown of ADATs main functions.

1.3A Transport

The transport is like most standard multitrack recorder transports. Tape motion controls include play, fast forward, rewind, stop, record, and pause. The counter shows elapsed time from the beginning of the tape, or the time from where you last reset the zero counter.
1.3B Record/Monitor functions
ADAT does much of the recording/monitoring switching work for you. Generally, tracks monitor whats on tape until you initiate recording (typically by punching), at which point any tracks set to record monitor the inputs so you can hear whats being recorded. For live multitrack recording, a special mode lets you monitor all eight inputs regardless of record status. The input jacks are wired using innovative switching techniques to allow for fast track selection, patching, and track switching. Section 2.2C explains this in more detail.

1.3C Punching

Punch-in and punch-out are gapless and glitchless. Digital crossfades can be set to any of four different crossfade times.
A user-supplied momentary footswitch allows for no-hands punch-in and out. The BRC can do auto punch in and out referenced to sample-accurate location points.

1.3D Autolocation

You can set three autolocate points on the front panel or on the LRC Remote; simply pressing a button will cause ADAT to seek and find the desired point. Looping is also possible by shuttling between two locate points. An auto play feature can automatically put ADAT into play mode when the autolocation operation is complete.

To sync together two or more ADATs, connect the Sync Out from the master to the next ADATs Sync In. Its Sync Out can in turn feed a third ADATs Sync In, etc. This requires a shielded dual male, 9-pin D connector cable available at your Alesis dealer. For more information on syncing ADATs together, see Chapter 5.

METER BRIDGE

To connect ADAT to the Alesis RMB Remote Meter Bridge, run a dual male, 9-pin D connector cable from the ADAT Meter Bridge out connector to the RMB input connector.

FOOTSWITCHES

Any momentary single-pole/single-throw footswitch, normally open or normally closed, will work for the two footswitch functions. These should be plugged in prior to power-up so that ADAT can configure itself for the type of footswitch being used.
3.0 POWER-UP AND TAPE INSERTION
After all connections are made, turn on power. ADAT first checks whether a tape has been inserted.
If a formatted tape is present, the counter shows the elapsed time since the beginning of the tape. If an unformatted tape is present, the counter will show noFO, and the FORMAT LED will flash to indicate that the tape needs formatting. At this point you should format the tape (see next section). If there is no tape, the counter shows "----" to indicate no tape is present.
Insert the end with the hinged door first, label side up, until you encounter a slight bit of resistance. Push gently on the center of the cassette until ADAT draws the tape inward. Once ADAT has started to pull in the tape, do not keep pushing the tape in. Note: to record on a S-VHS cassette, the write protect tab (located on the spine of the cassette) must be intact. If you try to record on a tape that has had the write protect tab broken off, the display will read "Prot" and the ADAT will not record on the tape. This allows you to prevent accidental erasure of valuable recordings. To record on a tape that has had the tab broken off, simply use a piece of scotch tape, label, etc. in place of the write protect tab to completely cover the hole in the cassette's spine.

FORMATTING A TAPE

Just as formatting a floppy disk lets a computer know where to place data, formatting an ADAT tape time-stamps the tape to single-sample accuracy so that audio is referenced to an accurate time base. This allows for simplified synchronization, accurate tape counter readings, and intelligent autolocation with the BRC Remote Control. When formatting begins, ADAT writes some setup data during the first two minutes and 15 seconds of tape, then at time -00:05, writes the time in minutes and seconds onto a special sync track. This does not use up any of the eight audio tracks. Please note: The display shows timings with a period separating the hours and minutes (00.00), but this manual shows a colon instead of a period for clarity (00:00).

3.1D Record a "Benchmark" Tape
We recommend that you format and record a new tape with any signal, such as a test tone, in a single pass with no overdubs during the first week of operation. Store this tape in a safe, dry location and don't use it for any other purpose. Such a "benchmark" tape is useful to determine if the error correction rate is increasing over time because the heads need to be cleaned, or if a tape is defective. See Section 9.2.
TRACK RECORD/MONITOR CONTROLS
These controls determine which tracks will be recorded on in record mode, and whether tracks will monitor the input or taped signal.
3.2A Record Enable Buttons
To record enable a track, press the tracks associated record enable button. The track RECORD LED will flash to indicate the track is record-ready. Recording will begin, as indicated by the RECORD LED being lit steadily, if the transport is put into record mode (section 3.4F). To turn off record enable, press the tracks associated record enable button again. Its RECORD LED will turn off. Record enable buttons cannot be turned on or off while youre in record.

3.2B Auto Input Monitor

This switch toggles between two tape/input monitoring options. It determines what signal will appear at the ADAT's Output jacks when a track is record-enabled (red LED flashing). When a track monitors the input signal, its associated INPUT LED is lit.
With Auto Input OFF (AUTO INPUT LED off), all record-enabled tracks monitor the input signal and all other tracks monitor the taped signal. With Auto Input ON (AUTO INPUT LED lit), there are two selectable modes to choose from: Mode 1: This is the default mode and allows input monitoring of record enabled tracks in Record, Stop, Rewind, or Fast Forward; but not in Play. In Mode 1 you are always monitoring the input of record enabled tracks, except in Play. This allows the engineer to hear musicians even when the deck is stopped, without changing any console settings. Mode 2: This mode monitors the input of record enabled tracks ONLY in Record mode. In Mode 2 all tracks monitor the taped signal until ADAT enters Record, at which point the record-enabled tracks monitor the input signal. This means the
engineer will not hear the musicians "live" through the deck unless it is actually in record mode. To select Mode 2, press and hold SET LOCATE and press AUTO INPUT MONITOR. The counter will briefly display 'tAPE', indicating Mode 2. To switch back to Mode 1, press and hold SET LOCATE and press AUTO INPUT MONITOR. The counter will briefly display 'In', indicating Mode 1. The reason for having these two options is to accommodate different stages of the recording process. Auto Input Off is the normal option and is what you would use when first recording tracks. As you record, you want to monitor the input signal being recorded, as well as any signals from tracks youve already recorded on tape. However, when doing punch-ins and overdubs, Auto Input will probably be On so that you can hear what was recorded on tape for a given track right up to the point you want to punch in. As soon as ADAT punches into Record mode, the taped signal drops out as the monitor switches over to the input signal so you can hear whats being recorded to tape. After punch out, the track reverts to monitoring whats on tape.

3.2C All Input Monitor

With this function on (ALL INPUT MONITOR LED lit), the auto input monitor setting is overridden so that all tracks monitor their input signals regardless of their record enable status. All eight track INPUT LEDs will be lit. With All Input Monitor off, the Auto Input Monitor setting determines track monitoring.

3.2D Digital Input

This switch determines whether ADAT will record from its analog inputs (balanced or unbalanced) or digital input. To record from the digital input, press the switch; its LED will light. All eight channels will be received via the fiber optic connection (section 6.1) and the analog inputs will be ignored. DIGITAL IN can be turned on or off only when the ADAT is in STOP mode. When recording while DIGITAL IN is on, the ADAT's speed is slaved to the clock of the incoming digital signal. The PITCH controls will have no effect when recording from the digital inputs, although they will remain lit. Do not turn on DIGITAL IN if nothing is connected to the digital input, since the ADAT will "hunt" for a clock that isn't there, causing long sync times. (For the one exception to this rule, see Section 6.1A.)

SETTING LEVELS

Unlike analog tape recorders, whose meters indicate 0 VU at the ideal nominal recording level, with 10 to 15dB headroom above the point, 0dB on ADAT represents
the maximum possible signal level. Signals above 0dB will be clipped and lead to digital distortionan ugly, splattering sort of sound. As on most digital recorders, O dB on the ADAT meter is referenced to full scale, the maximum signal that can be recorded in 16 bits. Reference-level signals plugged into ADAT are recorded 15 dB below full scale. For example, if your mixer has +4 dBu balanced outputs that are connected to ADAT's +4 dBu multipin ELCO connector (or it has -10 dBV unbalanced outputs connected to ADAT's 1/4" phone jacks), when your mixer's meter reads 0 VU, the ADAT meter will read -15 dB. Therefore, you can run your mixer levels "into the red" over 0 VU and still not distort the ADAT until the mixer's meter reads "+15". Just remember that no matter what, if ADAT's meters indicate 0 dB (highest red LED lit), distortion is on the verge of occurring. Theoretically, the lowest noise and distortion in an ADAT recording occurs just as the highest input peaks barely reach 0 dB full scale. Unlike analog recorders (which get more and more distorted with higher levels), an ADAT tape that is recorded "in the yellow" will sound great. However, in setting levels you must strike a balance between what you gain by recording at high levels, and what you might lose if the incoming signal hits the "digital brick wall" above 0 dB and distorts on a peak. This is especially true in live recording, where peak levels are hard to predict. You must also be careful when setting levels to make sure that the mixer isn't distorting. In critical situations, consider limiting the input signal using the Alesis 3630 Compressor/Limiter to ensure against overload and get a maximum level without distortion. The ADAT meters are the instantaneous peak reading type: any voltage, no matter how short, will be registered, because the peak level is all that matters to ADAT. Other meters (as on most mixing consoles) may have different ballistic characteristics or show average level instead of peak. It is normal for them not to match the ADAT meters exactly. The RMB Remote Meter Bridge provides peak metering for four ADATs in a rack-mountable package, and can be mounted above the console or the BRC Master Remote Control. The RMB also features peak-hold features that make it easier to avoid distortion.

TRANSPORT CONTROL OPERATION
The transport controls resemble those of a conventional tape recorder, although there are several extra features.

3.4A Eject

Press to eject the tape from ADAT. If the tape is moving, it will stop before ejecting. Note: This control does not operate while recording or formatting to avoid interrupting these processes.

3.4B Rewind

Press to rewind the tape, as confirmed by the REW LED. When fully rewound, the REW LED turns off and the STOP LED lights.
Pressing Rewind while recording punches out before rewinding. Engaged tapes rewind at about ten times normal speed. Disengaged tapes rewind at about twenty times normal speed. For the fastest rewind, press the Stop button twice, or until the Stop LED flashes, before pressing REW. Pressing Rewind while holding the Play button initiates review mode. The tape rewinds at about three times normal speed, and you can hear chunks of attenuated audio so you know where you are in the tape. The PLAY LED will be lit, and the REW LED will flash. Releasing the Rewind button returns to normal Play mode.

3.4C Fast Forward

Press to fast forward the tape, as confirmed by the FFW LED. Upon reaching the end, the FFW LED turns off and the STOP LED lights.
Pressing Fast Forward while recording punches out before fast forwarding. Engaged tapes fast forward at about ten times normal speed. Disengaged tapes fast forward much faster. For the fastest rewind, press the Stop button twice, or until the Stop LED flashes, before pressing REW. Pressing Fast Forward while holding the Play button initiates cue mode. The tape fast forwards at about three times normal speed, and you can hear chunks of attenuated audio so you know where you are in the tape. The PLAY LED will be lit, and the FFW LED will flash. Releasing the Fast Forward button returns to normal Play mode.

3.4D Stop

This button performs three functions.
Stop the transport. Push to stop any function involving tape motion. A lit STOP LED indicates that the tape is not moving and is engaged. A flashing STOP LED indicates that the tape is not moving and is disengaged. Disengage/engage the tape. While the STOP LED is lit, press STOP again to disengage the tape (STOP LED flashes). While the STOP LED is flashing, press
STOP again to engage the tape (STOP LED is lit). Entering Play or Record will also engage the tape.
Punch out. While recording, if you press and hold PLAY then press STOP, the tape continues to play but any tracks that were recording exit record mode.

3.4E Play

Press to play the tape (PLAY LED is lit). The Play button by itself has no effect while playing, recording, or formatting. While locating, pressing Play will cause ADAT to start playing after finding the location (PLAY LED will flash); pressing Play twice stops the locate procedure and ADAT immediately goes into play mode. Pressing Play in any mode other than locating causes the transport to enter play mode, and the PLAY LED lights. Note: What happens when you press Play after inserting a tape into ADAT depends on whether the tape being played is formatted or not:
Formatted. The tape plays normally and the counter shows the elapsed time since the beginning of the tape. Unformatted tape. ADAT will detect the lack of a format and flash the Format LED while displaying "noFO". Tape transitions from a formatted to unformatted section while playing back. ADAT will detect the lack of a format and flash the Format LED while displaying "noFO". Tape transitions from a formatted to unformatted section while recording. ADAT will detect the lack of a format and stop.
3.4F Record/Punch In or Out
Use Record to enter or exit record mode, and to format a tape. To start recording:
Press and hold Play, then press Record, to cause any recordenabled track to enter record mode. This is recommended for punching on the fly. Press and hold Record, then press Play, to cause any recordenabled track to enter record mode. This is recommended for initiating recording when the tape is stopped, or for punching on the fly.
To punch out and stop the transport, simply press Stop. There are three ways to exit record mode (punch out) yet have the transport continue to play; use whichever one is most natural to you.
Press and hold Play, then press Record. Press and hold Record, then press Play. Press and hold Play, then press Stop.
Caution: If the FORMAT LED is lit, entering record will format the tape (see sections 3.1 and 5.2). This will ERASE any audio previously recorded.

5.0 MULTIPLE ADAT BASICS

Two ADATs, with one serving as the master recorder and the other serving as the slave, provide additional possibilities:
16 tracks of synchronized digital audio storage. Simplified backup (see Chapter 6). Easy musical collaboration with other ADAT-equipped musicians. Easy creation of safeties and archives of parts. Example: Suppose your rhythm section is in four tracks of one ADAT. You can then do eight tracks worth of guitar, vocal, brass, or other overdubs in the other ADAT, and bounce the keeper parts over to empty tracks in the original tape. Once these tracks are filled up, you can then do a premix to the second ADAT, and continue recording on empty tracks in the second ADAT.
It is also possible to synchronize up to 16 ADATs for 128 tracks. One ADAT serves as the master and all the others as slaves. Therefore, operating procedures are similar to using two ADATs, just that there are more slaves. Important: In a multi-ADAT system, all ADATs should be of the same software version for best performance. To check the software version, hold Set Locate and press Fast Forward on each machine. The software version of the ADAT will show in its display for a moment. If you must mix software versions temporarily, the latest software version should be the master machine. Software upgrades are available through Alesis to make sure all machines are compatible. Contact Alesis Product Support for assistance.
SYNCHRONIZING MULTIPLE ADATS
5.1A Hooking Up Multiple ADATs
Synchronization requires a dual male, 9-pin D cable for each pair of ADATs to be synchronized. This connection can be made while power is on or off, and ADATs do not need to be turned on in any particular order in a multiple ADAT system. Use the correct cables: Most problems in multi-ADAT systems are the result of using the wrong cables. The 9-pin cable must be shielded, and wired pin-to-pin. Alesis Sync Cables that meet this specification are available from your ADAT dealer. Use the shortest length practical for your arrangement.
Connect one end of the cable to the master ADATs Sync Out jack. Push the connection in firmly, then tighten the screws at each side of the connector. Connect the other end of the cable to the slave ADATs Sync In jack and tighten it as above. If there are additional slaves, connect one end of an Alesis Sync Cable to the first slaves Sync Out jack, and the other end to the second slaves Sync In jack. Its Sync Out jack then connects to the third slaves Sync In jack, and so on.

5.1E Independent Slave Mode
If the master ADAT is stopped, then each of the slaves will function independently. For example, you can press Play on one of the slaves (or change the auto input monitor, etc.) and it will go into play; the other slaves will not respond. However, any time you press Play on the master or initiate any transport function, it will take over and control the slaves.
FORMATTING WITH MULTIPLE ADAT SYSTEMS
Formatting works similarly to formatting on a single ADAT. However, it is necessary to consider what the slave does when formatting is initiated on the master.
5.2A Master Format Enabled and Performing a Complete, Start-toFinish Format
If the master format is enabled, performing a complete start-to-finish format, and the slave tape is not formatted:
If the slave format function is on, the slave rewinds to the start of the tape and does a complete format. If the slave format function is off, the slave rewinds to the start of the tape and plays, but displays noFO (no format) while flashing the format LED.
If the master format is enabled, performing a complete start-to-finish format, and the slave tape is formatted:
If the slave format function is off, the slave rewinds to the start of the tape and plays in sync with the master.
If the slave format function is on, the slave rewinds to the start of the tape and does a complete format.
Note that if any channels are record-enabled, they will start recording at time 00:00.
5.2B Master Format Enabled and Extending the Format
If the master format is enabled, extending the format, and the slave tape is not formatted:
The slave plays, but displays noFO (no format) while flashing the format LED.
If the master format is enabled, extending the format, and the slave tape is formatted:
If the slave format function is off, the slave autolocates to the same time as the master and plays or records in sync. If the slave format function is on, the slave autolocates to the same time as the master, then format extension begins.
Note that to properly extend the format, the master and slaves should be playing in sync before punching into format record.
5.2C Master Format Disabled
This assumes that the master initiates the record/play function. If no master channels are in record mode, the master will play, but send record commands to the slaves if the master tape is rewound to the very beginning, or in the audio portion of the tape (i.e., past time 00:00). If the master initiates recording from anywhere in the tape and the slave format function is off:

7.0 COMBINED MULTITRACK/ MASTERING DECK
ADAT can serve as a combination 6-track multitrack recorder and 2-track mastering deck. Record your audio into tracks 1-6, then run them through a mixer into tracks 7 and 8. Tracks 7 and 8 then contain the stereo master recording. An alternative is to record 5 tracks of audio, and dedicate one track to SMPTE time code or some other synchronization protocol. MIDI sequencers can be synched to the tape, and used to drive virtual instruments that also feed the mixer.

ARCHIVING

ADAT is superb for archiving applications.
Archive speeches and broadcasts. ADAT can record over five hours of mono material by recording 40 minutes on each track. Record over 2-1/2 hours of stereo mixes. Archive them by mixing down to four sets of stereo pairs. Record libraries of stereo samples into ADAT. Again, this gives over 2-1/2 hours of recording time.

BOUNCING

Although ADAT requires the BRC to do digital bouncing, standard bouncing using the analog outputs results in virtually imperceptible loss of fidelity. Tracks can be bounced within ADAT, as well as to other machines.

LIVE RECORDING

ADAT is excellent for live recording because of its compact size and easy operation. Eight tracks allow for recording audience sounds, ambience, and individual soloists as well as a stereo mix off the PA.
USING ADAT WITH MIDI SEQUENCERS:VIRTUAL TRACKING
There is a trend for hard disk recording and playback to occur within a software MIDI sequencer environment, however ADAT can offer much of the same flexibility without the added expense of a new program or hard disk recording system.
Stripe one ADAT track with SMPTE, and sync your sequencer to this SMPTE signal by whatever means you normally use. As you control ADATs tape motion with the transport controls, the sequencer will automatically follow along, letting you mix digital recording with any sequencer.

VIDEO LOCATION RECORDING

With ADAT, there are enough tracks to stripe SMPTE and record seven tracks of dialog/sound effects on location. ADAT also makes an excellent mixdown deck for new multichannel formats (such as surround sound) that require more than two tracks.

MODULAR RECORDING

Collaborations work particularly well with dual-ADAT systems. You can record your tracks into one machine, then do a premix into two tracks of the second machine, which is of course synchronized to the first. Send this tape to your partner, who adds parts in the other tracks. When the tape comes back, just pop it in the second deck, and your partners parts will be in sync with what you laid down originally.
8.0 ABOUT THE ADVANCED FEATURES
There are some extra functions built into each ADAT that are not listed in the main text of your ADAT manual which we will discuss here. While holding the SET LOCATE switch and pressing certain specified switches, these extra functions can be accessed. These extra functions are divided into two sections: 1 Those that you may need one day. Accessing these functions is safe and easy to do. We have listed these below. Those that are purely for diagnostic and service purposes which should NOT be accessed. They could put your ADAT out of alignment and even possibly damage your tapes.

wrong direction, will destroy them. Opening the case of your ADAT will void the warranty. Maintenance of the ADAT should be based on the Advanced Information Indicator or if the unit begins to behave erratically. To determine if these symptoms are caused by dirty heads, (not a defective or worn tape), keep a "benchmark" tape from the first weeks of operation set aside in a safe place (See Section 3.1B). If the ADAT Advanced Information Indicator lights frequently when playing back this tape, it is likely that head cleaning is needed, particularly if several hundred drum-on hours have elapsed since the last cleaning. To display the number of hours the heads have been in use, press SET LOCATE and STOP. Call Alesis Product Support for more information about head cleaning and authorized Alesis Service Centers.
TAPE MAINTENANCE - SAFE TAPE
ADAT tapes are no different than any standard tape: they must be treated with care. Never expose ADAT tapes to temperature extremes, strong magnetic fields (such as speakers), high humidity, dust and so on. You should always practice SAFE TAPE.
Don't leave your tapes near speakers, power amps or other potential magnetic fields such as televisions or electrical devices. Don't subject your tapes to extreme temperatures or wild temperature fluctuations. Don't expose your tapes to high humidity, moisture or high dust levels. Don't leave your tapes on the dashboard of your car. (In fact, never leave ADAT tapes in a car EVER. Keep them with you at all times!) Certainly, no matter how tempted you are to open the shutter to see what is inside, NEVER TOUCH THE TAPE. The magnetic particles on your ADAT tape need to be preserved in the condition in which they were recorded. The oils from your fingers WILL damage your tapes as well as get on the heads and damage them. Never turn off the ADAT power while the tape is threaded. This leaves the tape bent around the rollers and head. Press STOP until the tape is disengaged before turning off power.
At the end of every session you should rewind the tape all the way to the leader, stop, eject the tape, remove it from the ADAT and place it in its protective case. This cuts down on the amount of dust that can enter the transport and keeps wear on the tape at a minimum.
Practice "safe tape" at all times because you can never retrieve lost data. If you are archiving your tapes, make sure they are stored in environmentally stable conditions, i.e. a cool dry place. If you do archive your tapes, you need to check them once a year. Run each tape through your ADAT from end to end. This will prevent buildup that can occur when a tape is left simply "sitting". Of course, for your super sensitive or important material, nothing beats making multiple digital backups. Every year or so, simply do another digital backup onto a brand new tape.

10.0B Digital Tape Recording Basics
With digital tape recording, the technology is very similartape moves past a record head, and plays back through a playback head. However, the signal recorded on tape is very different. Audio signals entering each channel of ADAT first pass through an analog-to-digital converter (ADC), a device that takes 48,000 snapshots of the signal level every second. Each snapshot is assigned a specific numeric value that corresponds to its level. These numbers, which represent coded audio, are then converted into an audio signal that can be recorded on tape. Fortunately, recording a number on tape doesnt degrade the signal. During playback, a digital-to-analog converter (DAC) reads the numbers from tape and outputs a corresponding level. This creates a stairstep reconstruction of the
original signal, which is close to (but not exactly) the same as the original signal. To complete the process, this stairstep signal is smoothed by a low pass filter. The result is natural-sounding audio that sounds virtually unchanged from what was originally recorded.
10.0C Why Does ADAT Use S-VHS Cassettes?
Alesis has built its reputation on providing professional levels of quality and innovation at prices associated with consumer gear. When it was time to produce a digital tape recorder that would be suitable for any application from home/project studios to pro-level audio studios and video dubbing suites, our design team decided to use existing, mass-production technology wherever possible to cut costs without sacrificing performance; and the wide tape width of S-VHS tape allows ADAT to use wider track width for more reliable digital recording. It's especially well suited to ADAT's 8 track format. S-VHS recording technology offers more than enough bandwidth to record eight tracks of audio, low cost, and field-proven engineering. S-VHS tapes are built to higher standards than standard VHS tapes, and can take the tape shuttling required by professional audio applications. Theres also a matter of convenience. S-VHS tape cassettes are inexpensive compared to reel-to-reel tape, readily available, compact, and easy to transport and store.
10.1 APPENDIX 2: GLOSSARY AES/EBU Interface
A two-channel, digital audio hardware/software standard. The AES/EBU interface allows for data communication between professionally-oriented digital devices (such as CD players, digital signal processors, hard disk recording systems, synthesizers with AES/EBU outputs, digital audio workstations, etc.).
Analog-to-Digital Converter

10.3 APPENDIX 4: SCHEMATICS
Wiring Diagram for ELCO Connector
Pin out letters are referenced to the alphabetical designation on a standard 56-pin ELCO connector. Channel In 1 In 2 In 3 In 4 In 5 In 6 In 7 In 8 Out Out Out Out Out Out Out Out GND NN CC t FF w KK z p Z P D T H W L A NEG JJ y n MM BB EE v l c U J M B a R E POS HH x m LL AA DD u k d V K N C b S F r,s,h,j,e,f,X,Y

Additional GNDs:

Note: The larger of the two key notches is on the bottom.
ELCO is a registered trademark of Elco Corporation - a Kyocera Group Company
Addendum to the ADAT reference manual: Version 4.0 software
This document describes the changes/additions to ADAT version 4.0 software.
Write Protect Tab Check Override
If you want to record on a tape which has had its write-protect tab removed or damaged, you can now override it from the ADATs front panel and allow recording to take place. Normally, the write-protect tab is an essential component to remove when you want to retain the information on an important tape. ADAT scans for the presence of a write-protect tab when a tape is inserted. If no tab exists, recording is prevented. However, once the tab is gone, it's gone. Now, you can tell ADAT to ignore the absence of a write-protect tab, and permit recording to take place anyway. Heres how you do it: 1 Hold the [SET LOCATE] button and press RECORD ENABLE [2]; The display will momentarily read PrOf, indicating that the Write-Protect tab is not being checked. Repeat step 1 to switch Write-Protect Tab Check back on; The display will momentarily read PrOn.
Note: This override will automatically be deactivated whenever you eject a tape, or turn the power off. You must re-enter the override each time you use a new tape or start a new session.
Setting Tape Length and ST-180 Compatibility
The ADAT has been optimized to take advantage of the extra recording time on tapes longer than the standard ST-120. You can now use ST-180 tapes, for over one full hour of recording time. ST-60 tapes can also be used for shorter projects; ADAT automatically recognizes the shorter length of the ST-60 because the hubs are large. However, there is no way for ADAT to tell apart a ST-120, ST-160 or ST-180 tape, since these all use the same, smaller size hubs. Therefore, you must set the tape length on the ADAT. To do this: 1 Hold the [SET LOCATE] button and press the [FORMAT] button; This display will read t60. Repeat step 1 to advance through the available tape length choices. The display will briefly read either t120, t60, t160 or t180. The tape length setting is not reset when a tape is ejected. However, if you power down and up again, the tape length setting will revert to T-120. If connected to a BRC, and you set the tape length from the BRC, the individual ADATs will retain their tape length setting after power down.