LINE CONDITIONERS

P ROTECTORS
Although the LX20 can tolerate typical voltage variations, the AC line voltage may contain spikes or transients that can possibly stress your gear and, over time, cause a failure. There are three main ways to protect against this, listed in ascending order of cost and complexity: Line spike/surge protectors. Relatively inexpensive, these are designed to protect against strong surges and spikes, acting somewhat like fuses in that they need to be replaced if theyve been hit by an extremely strong spike. Line filters. These generally combine spike/surge protection with filters that remove some line noise (dimmer hash, transients from other appliances, etc.). Uninterruptible power supply (UPS). This is the most sophisticated option. A UPS provides power even if the AC power line fails completely. Intended for computer applications, a UPS allows you to complete an orderly shutdown of a computer system in the event of a power outage, and the isolation it provides from the power line minimizes all forms of interference spikes, noise, etc.
If your AC power is unstable or subject to occasional browns-outs or interruptions, use a professional power conditioner or uninterruptible power supply. Some people who have experienced problems with ADAT operation have had those problems disappear completely after installing proper power conditioning.
A NALOG A UDIO CONNECTIONS

ABOUT AUDIO CABLES

The connections between the LX20 and your studio are your musics lifeline, so use only high quality cables. These should be low-capacitance shielded cables with a stranded (not solid) internal conductor and a low-resistance shield. Although quality cables cost more, they do make a difference. Heres how to route cables to the LX20: Do not bundle audio cables with AC power cords. Avoid running audio cables near sources of electromagnetic interference such as transformers, monitors, computers, etc. Do not place cables where they can be stepped on. Stepping on a cable may not cause immediate damage, but it can compress the insulation between the center conductor and shield (degrading performance) or reduce the cables reliability. Avoid twisting the cable or having it make sharp, right angle turns. Never unplug a cable by pulling on the wire itself. Always unplug by firmly grasping the body of the plug and pulling directly outward.
When connecting audio cables and/or turning power on and off, make sure that all devices in your system are turned off and the volume controls are turned down.

REAR PANEL INPUT

OUTPUT L AYOUT
The LX20s rear panel has 8 unbalanced phono jack inputs, and 8 unbalanced phono jack outputs.

RECORD ENABLE BUTTONS

Each recording enable button corresponds to its like-numbered track, and controls the tracks record status. They are also sometimes used in combination with other buttons to select more advanced options.

TRANSPORT CONTROLS

These control tape movement (REWIND, FFWD, STOP, PLAY, and RECORD).

EJECT BUTTON

If you guessed this ejects the cassette, youre right. ADAT LX20 Reference Manual 21

INPUT SELECT BUTTONS

These determine how signals, both analog and digital, are routed to the LX20.

PITCH CONTROL BUTTONS

These increase or slow down the playback and record speeds to change pitch.

LOCATION BUTTONS

The LX20 can find particular places on tape. Example: You might want to shuttle rapidly between a chorus and verse while overdubbing; by storing these locations, you can push the corresponding button to tell the tape to go fetch, and park the tape at the desired location.

E DIT, FORMAT ,

SELECT BUTTONS
These are really individual functions grouped in the same general area. They will be described in detail as needed.
AUTO LOOP /AUTO RECORD BUTTONS
The LX20 can automate certain tape movement procedures, such as automatically returning to a particular point after overdubbing, playing a section repeatedly, automated punching to record over a specific section of a track (e.g., a bad phrase in an otherwise perfect vocal), and so on. The Auto Play, Auto Return and Auto Record buttons, in conjunction with the Location buttons, control the auto functions.

D IFFERENCES COMPARED

A NALOG R ECORDING
Recording on the LX20 is very similar to most multitrack tape machines. With a formatted tape loaded, put one or more tracks into record-ready, adjust record levels on your mixer, set the input monitor mode, locate to where you want to begin recording, and engage record. However, there are two main differences, described next.

THREADED

UNTHREADED TAPE
The LX20 uses a rotating head drum which records and plays back digital audio signals from tape. Even when the tape is stopped, it remains threaded or engaged against the spinning head drum for a period of time. This allows for going into play or record faster, as well as provides cue and review functions that let you monitor the tape audio at faster-than-normal play speeds. When threaded and stopped, the STOP button LED is lit steadily. When the tape is unthreaded (the STOP LED flashes), it takes a little bit of time for the tape to wrap around the head drum before it can go into play or record. Cue and review functions are not possible while the tape is unthreaded. When the tape is threaded and stopped, you can manually unthread it by pressing the STOP button. The STOP LED will flash, indicating the tape is now unthreaded. Pressing either PLAY or STOP, or PLAY and RECORD to engage recording, rethreads the tape. If the tape is threaded, and no transport activity (play, record, rewind, etc.) occurs for 4 minutes, the tape will automatically unthread itself to minimize tape wear.

TAPE FORMATTING ?

Standard blank S-VHS tapes must first be formatted in an ADAT-family machine before they can be used. Formatting prepares the tape for recording and synchronization, as described later.
Power-Up and Tape Formatting - Chapter 3

CHAPTER 3

P OWER-UP AND TAPE F ORMATTING

POWER-UP

TAPE INSERTION
Patch the LX20s power cord between the rear panel, three-prong power socket and a properly-wired AC outlet receptacle. Please take account of the grounding considerations mentioned in Chapter 1.
The LX20 can produce a transient audio signal during power up and power down. When turning the LX20 on or off, keep the monitor levels low. Turn the LX20s power on by pressing the POWER button. At power-up the display briefly looks like this:
In a few seconds, the display will change depending on the status of the tape in the transport. If a formatted tape is present, the TIME counter will show the elapsed time since the beginning of the tape (unless it is somewhere in the first two minutes of tape, called the lead and data sections):
0 H 15 M 48 S 21 n0 F0 -- -- -- --
If an unformatted tape is present, the FORMAT indicator will flash and the TIME counter will read:
If there is no tape, the display shows:
Insert the tape with the hinged door end first, label side up, until you encounter a slight bit of resistance. Push gently on the center of the tape cassette until the LX20 draws the tape inward. Never force the tape into the cassette door.
Chapter 3 - Power-Up and Tape Formatting

SETTING TAPE LENGTH

The LX20 can use tapes longer than the standard ST-120 length (an ST-180 tape gives over one hour of recording time, an ST-160 gives 53 minutes). The LX20 automatically recognizes ST-60 tapes and adjusts itself accordingly, but cannot tell apart ST-120, ST-160 or ST-180 tapes. The LX20 assumes you are using a ST-120 tape. Therefore, you need to set the tape length on the LX20 when using either ST-160 or ST-180 tapes. To do this, hold the SET LOCATE button and press the FORMAT button. Each press of the format button cycles through the following options: ST-60, ST-160, ST-180, and ST-120. When the display shows the correct tape length, release both buttons. Ejecting a tape does not reset the tape length, but powering down resets to T-120. If you insert a tape with Tape Length set to something other than ST-120, the display will briefly flash the selected length to remind you that you are using a non-standard setting. If using multiple LX20s/ADATs, all connected machines must use tapes of the same length.

DEFEATING THE WRITE P ROTECT T AB
To record on or erase/format a S-VHS cassette, the write protect tab (located on the cassettes spine) must be closed or taped over. If you try to record on a tape that has had the write protect tab broken off or is slid open, the PROT indicator in the display will light and the LX20 will not record on the tape. This prevents accidental erasure of valuable recordings. To record on a tape that has been protected, eject the tape and slide the write protect tab so that it is closed. If the tab has been broken off, it is still possible to defeat write protection. To defeat write protection: x Press and hold the SET LOCATE button. While holding the SET LOCATE button, press the Track 1 RECORD ENABLE button (located immediately to the right of the power switch). Each press of the Track 1 RECORD ENABLE button toggles between protect on and protect off (shown in the display as Prot On and Prot OFF respectively). The PROTECT indicator in the display turns on and off to confirm the setting. ADAT LX20 Reference Manual
GENERAL FORMATTING PROCEDURE
Formatting consists of inserting the tape, selecting the sample rate, selecting the audio resolution, then initiating formatting. Following are the steps needed to format a tape.
Operation Cassette insertion
You Do Insert a fresh, blank S-VHS tape into the tape well.
You see The displays FORMAT indicator lights while the counter display reads noFO.
If you are reformatting an existing tape, rewind to the beginning (display shows LeAD). When extending the format of a tape that was not completely formatted, locate the tape to about 30 seconds before the tape transitions from showing tine in the display to showing noFo (no format). If the tape is not formatted and not rewound, the LX20 will automatically rewind back to the beginning. the CLOCK SELECT button until the display shows 44.1 kHz, 48 kHz, or DIGital Audio Clock (44.1 or 48 kHz)

Select Sampling Rate

44.1 kHz is ideal for use with digital mixers. Keep the signal at 44.1 kHz through the mixer and master it at 44.1 kHz, which is the sample rate for CDs. 48 kHz would need to be sample-rate converted to the CDs rate, which can subtly alter the signal. However, with analog mixers, 48 kHz is recommended because it gives superior frequency response. DIGital Audio Clock is relevant only if the LX20 is recording from a digital source. See Chapter 8. 3. Select Audio Resolution the FORMAT button until the display shows 20-bit (best fidelity) or 16-bit (compatible with older, Type I-only ADAT and ADAT-XT). The RECORD LEDs for tracks 1 through 8 will flash.

RECORDING

BENCHMARK TAPE
Alesis recommends that during the first week of operation, you format and record a new tape with any signal, such as a test tone, in a single pass with no overdubs. Store this tape in a safe, dry location and dont use it for any other purpose. Such a benchmark tape can help determine if the error correction rate is increasing over time because the heads need to be cleaned, or if a tape is defective.
Chapter 4 - Record and Playback Basics

CHAPTER 4

RECORD AND P LAYBACK BASICS

UNDERSTANDING

Before recording, familiarize yourself with the TIME counter in the displays top left corner. This counter shows the time reference stamped on a formatted tape as hours:minutes: seconds.hundredths-of-a-second.

0 H 15 M 48 S 21

CHANGE DISPLAY FORMAT
You can change the displays last two digits to show Frames Per Second (FPS; one frame is 1/30th of a second) instead of 100ths of a second. This is useful for matching the display on the Alesis BRC.
To change the display format: x Press and hold the SET LOCATE button. While holding the SET LOCATE button, press the Track 4 RECORD ENABLE button. Each press of the Track 4 RECORD ENABLE button toggles between the display showing dISP FPS (for frames per second) or dISP rEg. When set to FPS, a small F lights to the right of the time display.

THE INPUT

A NALOG A UDIO
The LX20 lets you choose one of three Input Modes for the analog audio inputs: 2-Input Mode 4-Input Mode Input 1 feeds Tracks 1, 3, 5 and 7. Input 2 feeds Tracks 2, 4 , 6 and 8. Input 1 feeds Tracks 1 and 5. Input 2 feeds Tracks 2 and 6. Input 3 feeds tracks 3 and 7. Input 4 feeds tracks 4 and 8. Each Input feeds its own track.

8-Input Mode

Record and Playback Basics - Chapter 4 The reason for these three modes is to take equal advantage of 2, 4 and 8 bus mixing consoles. To select the appropriate Input Mode, hold the ANALOG INPUT button and press one of the RECORD ENABLE buttons (18). The blue INPUT indicators, located along the bottom of the display below the VU meters, will illuminate to indicate the selected Input Mode. While holding ANALOG INPUT Press 1 or 2 Press 3 or 4 Press 5, 6, 7 or 8 Result to select 2-Input Mode. to select 4-Input Mode. to select 8-Input Mode. INPUT indicators light for Tracks 1 and 2 Tracks 1 through 4 All Tracks (1 8)
When using a 2-bus mixer, connect its two outputs to the LX20s unbalanced inputs 1 and 2, and select 2-Input Mode. Any time you want to record on an odd-numbered track, route the signal(s) to bus #1 or left. Likewise, to record onto an even-numbered track, route the signal(s) to bus #2 or right. By simply putting the desired track into record, the proper signal will get there, even though it is not connected directly to the tracks input jack. When using a 4-bus mixer, connect its four outputs to the LX20s unbalanced inputs 1 through 4, and select 4-Input Mode. To record on track 1 or 5, route the signal(s) to bus #1. Likewise, to record onto tracks 2 or 6, route the signal(s) to bus #2, and so on. With an 8-bus mixer, connect each bus to its like-numbered input. To record on track 1, send the signal to mixer bus 1, to record on track 2 send the signal to mixer bus 2, etc. 8-input mode is also recommended when feeding the LX20 from a mixer channels direct outs.

CHOOSE ANALOG OR DIGITAL INPUT
This select whether the LX20 records from signals present at the analog inputs or the optical digital inputs. For more about digital inputs and outputs, see Chapter 8. Operation Record from the analog inputs Record from optical digital inputs You press The ANALOG INPUT button The DIGITAL INPUT button You see The Input Block shows ANALOG The Input Block shows DIGITAL
Choosing Digital Input may involve setting the Clock parameter as well, depending on whether the LX20 is the master or slave in a digital setup. See Chapter 10, Digital Clock Considerations.

DIGITAL INPUT RE-ROUTING

By holding the DIGITAL INPUT button, you may reroute incoming channels to record on different tracks. Example: Digital audio received on channels 1 and 2 can be rerouted and recorded onto tracks 3 and 4. For more information about recording from the digital input and re-routing, see Chapter 10. 34 ADAT LX20 Reference Manual

SELECT T RACK(S)

R ECORDING
A track can be in one of 3 states: Safe The track RECORD indicator (the red bar located right below the meter) is off. Record-ready The track RECORD indicator flashes Recording The track RECORD indicator is lit solid
Heres how to enable a track for recording, as well as place it in safe mode. Note that the Record Enable switch toggles between two possible states each time you press it. Operation Enable track for recording You press The tracks associated RECORD ENABLE button (18) until You see The selected tracks REC light flashes to indicate it is record-ready. The selected tracks REC indicator will turn off to indicate it cannot record

Place track in safe mode

The record-enabled tracks RECORD ENABLE button (18) until
TAPE M OTION CONTROL: THE TRANSPORT
The transport buttons include REWIND, FFWD (Fast Forward), STOP, PLAY, RECORD, and EJECT. All of the buttons except EJECT have associated lights.
Press to stop the tape transport (STOP button lights steadily). The tape is not moving, but is threaded around the drum. The tape will unthread automatically if no transport movement occurs within 4 minutes. STOP will flash. To re-thread the tape, press STOP again (it lights steadily). Note that entering play from the unthreaded mode takes longer than when the tape is already threaded due to the time required to wrap the tape around the head.
Record and Playback Basics - Chapter 4
Press to start playback from the current tape location. The PLAY button also has special functions in Record and Autolocation modes, as described in Chapter 5. The following chart summarizes all possible Play button options. If the tape is Stopped Playing Formatting Locating Pressing Play causes Playback No change (playback continues) No change (formatting continues) Playback after the locate is complete You see PLAY button lights steadily PLAY button lights steadily PLAY button lights steadily PLAY light flashes during locate, then stays lit when locate is complete PLAY button lights steadily PLAY button lights steadily

DEFERRED P LAY

R ECORD
To automatically enter play mode after locating, press PLAY before a locate completes. To cancel deferred play while the tape is moving, press STOP, REWIND, FFWD, or a LOCATE POINT button. To automatically enter Record mode after locating, press PLAY and RECORD before a locate completes. To cancel deferred recording while the tape is moving, press PLAY, STOP, REWIND, FFWD, or a LOCATE POINT button.
Chapter 6 - Punching and Automated Recording

CHAPTER 6

PUNCHING AND A UTOMATED R ECORDING
Punching is the process of recording over a section of tape (for example, to replace a bad note in an otherwise good performance). Punch-in is where recording begins, and punch-out is where it ends. There are several ways to punch into and out of recording, either manually or automatically. If youre used to punching with analog tape machines, note that punch-out is immediate; there is no brief, silent gap after punching out.

M ANUAL PUNCHING OPTIONS

To punch-in: Select a track to record, press and hold RECORD, then press PLAY at the punch-in point. To punch-out: Press STOP. The transport punches out of record, then stops. Press PLAY. Press and hold RECORD, then press PLAY.
If you press PLAY and RECORD with no tracks record-enabled, the Record light will flash. Pressing individual track RECORD ENABLE buttons (simultaneously or in any order) can punch individual tracks in or out independently. The Record light will remain lit (or flashing in Rehearse mode; see Rehearsing) until you punch out of Record, usually by pressing PLAY or any other transport key. Operation You press Punch in using RECORD ENABLE While in Record mode and the button tape is running, press RECORD ENABLE button Punch out using RECORD While recording, press RECORD ENABLE button ENABLE button You see Record Enable indicator lights solid Record Enable indicator turns off
Punching and Automated Recording - Chapter 6

F OOTSWITCH

Pressing the punch footswitch is equivalent to pressing RECORD and PLAY. If the LX20 is already recording, pressing the punch footswitch exits Record mode but the transport continues to play. Note: Footswitch-controlled recording also works in conjunction with Rehearse mode and Auto Record mode.

Using the LX20 LRC Remote - Chapter 9
Chapter 10 - Multiple LX20/ADAT Operation

CHAPTER 10

M ULTIPLE LX20/ADAT OPERATION

O VERVIEW

The LX20 can work together with up to 15 other ADAT-family machines to provide a total of 128 tracks. ADAT machines have a sync bus that provides timing information for all ADATs in a system. When linking multiple ADATs together, the first machine in the chain is the master, and the rest are slaves. Each slave locks to the master and synchronizes to the master machines time reference. Using the 8-channel ADAT Optical Interface, you can also bounce (copy) tracks between machines in the digital realm. The result is a perfect copy (ideal for safety backups and archives) that is synchronized to the original with single-sample accuracy. See the applications section for creative ways to use multiple ADATs.

SYNCHRONIZING M ACHINES

Each slave to be synchronized requires a dual male, 9-pin D connector cable. Use only Alesis cables, which are available in three different lengths: 8", 30", and 30'. Other cables may cause erratic sync performance. To connect the bus (power must be off), patch one 9-pin D connector cable from the master SYNC OUT to the slave SYNC IN. A slave will automatically detect a master and enter slave mode. With more slaves, connect slave 2s SYNC OUT to slave 3s SYNC IN, slave 3s SYNC OUT to slave 4s SYNC IN, etc.
Applications - Chapter 11
ALESIS CORPORATION, LOS ANGELES
U.S. Patents 5,297,181 5,321,561 5,541,781
POWER INPUT 90-250 V 50-60 Hz 80 W MAX
THIS DEVICE COMPLIES WITH PART 15 OF THE FCC RULES. OPERATION IS SUBJECT TO THE FOLLOWING TWO CONDITIONS: (1) THIS DEVICE MAY NOT CAUSE HARMFUL INTERFERENCE, AND (2) THIS DEVICE MUST ACCEPT ANY INTERFERENCE RECEIVED, INCLUDING INTERFERENCE THAT MAY CAUSE UNDESIRED OPERATION.

CAUTION

RISK OF ELECTRIC SHOCK DO NOT OPEN

ADAT OPTICAL

WARNING/AVIS:
SHOCK HAZARD DO NOT OPEN. RISQUE DE CHOC ELECTRIQUE NE PAS OUVRIR. TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE. TO REDUCE THE RISK OF ELECTRIC SHOCK DO NOT REMOVE COVER (OR BACK). NO USER SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.

ACHIEVING LOCK

In a multiple-ADAT system, the slaves will chase the master (CHASE indicator lights on the LX20) and can only enter record once they are locked. Audio will not appear at an ADATs outputs until it is locked, as shown by a lit LOCKED indicator. For the fastest chase-lock performance in a multi-ADAT system, when possible use the Locate points to go to different tape locations.

INDEPENDENT SLAVE M ODE

If the master LX20 is stopped, each slave functions independently. Example: Press PLAY on one of the slaves and it will play, but the other slaves and master 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 M ULTIPLE TAPES
Formatting multiple ADATs works similarly to formatting on a single LX20, however there are some considerations unique to formatting multiple tapes. (For basic information on formatting, see Chapter 3.) The following chart indicates the possibilities for various slave and master format combinations. Remember that any record-enabled tracks will start recording at 00:00:00 of the formatting process.

Format Mode Complete

To properly extend a format, the master and slaves should be locked before punching into format record. Master format ind. Lit Slave format ind. Lit Slave formatted? No Result What you see
Rewinds to tape start, formats along with master Rewinds to tape start and plays along with master Rewinds to tape start, formats along with master Rewinds to tape start and plays along with master Slave plays

Complete

Extend
Autolocates to same time as master and begins format extension Autolocates to same time as master and plays or records in sync Slave autolocates to master, then format extension begins at the slave Slave plays
Slave FORMAT indicator lit solid TIME counter reads noFO (no format) Slave FORMAT indicator lit solid TIME counter shows current time TIME counter reads noFO (no format) TIME counter shows current time TIME counter shows current time TIME counter shows current time TIME counter reads noFO (no format)

RECORDING DIGITAL AUDIO

BOUNCING TRACKS BETWEEN ADATS
Use the ADAT Optical Interface to bounce between machines in a multiple ADAT system. The digital bus connects similarly to the sync cables, and the machines should be patched together in the same order (e.g., digital output 1 goes to digital input 2, digital output 2 to digital input 3, etc.). Refer to Chapter 8 for more information on connecting the digital bus.
If DIGITAL IN is selected and there is no optical input, the DIGITAL indicator (located in the Clock Block) will flash. With DIGITAL INPUT selected, the LX20 will record from the DIGITAL IN connector, and ignore the analog inputs. The optical bus carries the 8 tracks, with ADAT LX20 Reference Manual

M AKING DIGITAL BACKUPS

You can (and should!) back up LX20 tapes by copying all eight tracks to another LX20 (or ADAT-compatible machine) via the digital bus. Alesis urges you to back up whenever you have material you dont want to lose. This is not yet a perfect world. Synchronizing two machines together via the 9-pin sync bus allows for making sample-accurate copies, referred to the internal time code. This is the preferred way to make copies. Otherwise, you can simply start recording on the slave and play back from the master. This faithfully copies the audio information, but in all likelihood there will be a timing offset between the two tapes since it is impossible to start them at the exact same time unless they are synchronized together. Heres the complete procedure for creating a backup tape. Action Synchronize the master and slave You do With power off, connect a male/male, 9-pin D connector cable between the master SYNC OUT and the slave SYNC IN Connect a fiber optic cable between the master DIGITAL OUT and the slave DIGITAL IN Insert the tape to be backed up into the master, and a blank or formatted tape into the slave You see The master becomes ID1 and the slave ID2 on power-up
Establish digital audio connection Load machines with tapes
No visible change on machine
Cassette inserted indicator lights in both machines displays
To make a 20-bit backup, both machines must be Type II with tapes formatted in 20-bit mode. If the tape is unformatted, put the slave into FORMAT mode. If the tape is partially formatted, the slave tape needs to have its format extended. For safetys sake, write-protect the tape to be copied by sliding open the tapes write protect tab. Press the LOCATE 0 button Press the DIGITAL INPUT button on both the master and slave LX20 Press all slave RECORD ENABLE buttons Both TIME counters read 0:00:00.00 The DIGITAL indicator lights on both machines The RECORD indicators for all slave tracks will flash.
Return both machines to a common start point Enable digital inputs
Enable all slave tracks for recording
Be sure the master LX20s RECORD ENABLE buttons are switched off for tracks 18. Initiate tape cloning Press PLAY and RECORD on the master Press STOP on the master after backup is complete Both machines start, RECORD ENABLE indicators on slave machine light solid Both machines stop

POLARITY DIFFERENCES

The original ADAT inverted the polarity of the signal being recorded on tape, then flipped polarity again before going to the output jacks. As a result, the output was the same polarity as the input, so no phase problems were possible when using a single ADAT or a multiple ADAT system. However, neither the digital input nor the digital output was inverted. Therefore, if you digitally transfer the ADATs digital audio data to a DAT machine or hard disk recording system, the audio output from the other device would likely be out of phase with the ADAT, since it probably does not invert the analog signal after its D/A converters. Although this is not usually a problem, it may cause some confusion when mixing multiple audio signals from multiple sources, since there is a possibility that signals could become out of phase. To prevent this from occurring, the LX20 design has been improved so that the polarity remains constant from the analog to digital, and back to analog, domain. Like the original ADAT, the result from one machine, or multiples of the same machine, is the same: The input to output phase is correct. However, if two cloned tapes (copied digitally either with ADATs, ADAT LX20s, or both) are played back in sync on both an ADAT and an LX20, the outputs of the two machines will be out of phase relative to each other. The only known situation where this could cause a problem is as follows: Suppose you had been using a multiple ADAT system and you recorded a stereo signal across two machines (e.g., a stereo drum recording on tracks 8 and 9), where there is a common element to each track (i.e. center signal). If you replace one of these machines with an LX20 but play back the same type, the track playing back from the LX20 will be out of phase from the track played on the ADAT, canceling the center signal.
Applications - Chapter 11 Here are some possible solutions: Use a phase switch on your mixer (if your mixing board provides this) to invert the phase of a problem track to compensate. Wire your patchbay to reverse the input and output polarity of the LX20s in the system, but use standard cables on the ADATs in the system. This is recommended only for studios where master tapes will be exchanged between units or sent out of house. Digitally bounce one of the stereo tracks to the other ADAT so that both sides play back from the same machine. Better yet, plan recording sessions so that stereo tracks reside on the same physical tape in a multiple ADAT system.

CONNECTIONS

If you are replacing one or more of your ADATs with LX20s and have been using the short, 8" sync cables, you will need to use 1 meter cables (or longer) to make the connection between ADATs and LX20s. This is because the SYNC IN and SYNC OUT connectors have been moved on the LX20 rear panel compared to the original ADAT.

LOCKING

V IDEO: CODE-ONLY M ASTER
A common application in audio post-production is locking to video using time code recorded on the video tape. This requires a synchronizer interface, such as the Alesis AI-2 or BRC. The connections are: Run a balanced 1/4" TRS cable between the VTRs SMPTE OUT connector and the AI-2s SMPTE IN (if time code is recorded onto the tapes left or right audio track, connect the cable to the proper channels output connector). Patch a BNC connector from the house sync feeding the VTR (such as a blackburst generator), or the VTRs video out, to the AI-2 VIDEO IN. Connect the AI-2s SYNC OUT to the LX20s SYNC IN connector.
When the LX20 detects an on-line AI-2 or BRC, it will ID itself as a slave (ID 1) and the Clock will automatically switch to External (the EXT indicator will light in the Clock block). The AI-2 and BRC Reference Manuals contain more information.

LIBRARIES

ARCHIVES
The LX20 is superb for archiving purposes, such as speeches and broadcasts, stereo mixes or libraries of stereo samples. The LX20 can record over eight hours of mono material by recording approx. 60 minutes on each track (using ST-180 tape). Over four hours of stereo mixes or samples can be recorded by mixing down to four sets of stereo pairs (1/2, 3/4, 5/6, and 7/8).

M ODULAR R ECORDING

Collaborations work particularly well with a system consisting of two or more LX20s (and/or ADATs). You can record your tracks onto the master machine, then do a premix onto two tracks of a slave machine, which is perfectly synchronized to the master. Send this tape to your partner, who adds parts on the other tracks. When the tape comes back, just pop it into one of your machines, and your partners parts will be in sync with the original tracks you laid down. Include documentation with your tape that indicates info such as sample rate and Locate Point positions. Or, if youre both using BRC remotes, save your setup to the data section of tape (this is called saving the Table of Contents, or TOC). This way, you partner can pick up right where you left off.

COMPUTER CONTROL

MIDI SYSTEMS: VIRTUAL TRACKING
Many sequencing software manufacturers now integrate digital audio hard disk recording and playback into their sequencers. However, these types of systems tax computers to their limits, and in many cases require an expensive upgrade (faster processor, more RAM, additional hard drives and cards, backup system for the digital audio data, etc.) to obtain adequate results. Synching your existing MIDI sequencer to an LX20 can offer much of the same flexibility, as you can add digital audio to an existing sequence by recording into the LX20 as you monitor the sequenced instruments. Conversely, you can record MIDI data into the sequencer while its synched to the LX20. Synchronizing the LX20 and sequencer requires a time code interface, such as the Alesis BRC, Steinberg ACI, or JLCooper DataSync 2, allof which can convert the LX20s SYNC OUT to SMPTE or MIDI Time Code (the most common time references for MIDI sequencers). Heres the general hookup procedure. Connect the LX20s SYNC OUT (or SYNC out from the last slave in a multiple ADAT system) to the time code interface SYNC IN. Connect the timecode interfaces MIDI OUT to your sequencers MIDI IN. Set your sequencer to synchronize to the MTC being received from the time code interface (usually by selecting the sequencers MTC sync mode). As you control the LX20s tape motion with the transport controls, the sequencer will automatically follow along, letting you mix digital recordings with virtual MIDI tracks recorded in a MIDI sequencer. However, virtual tracks also have limitations, such as the occasional stuck note or limited polyphony. 67

If the LX20 freezes up often, consider buying an uninterruptible power supply. Many users who experienced inconsistent ADAT operation reported that these problems disappeared after cleaning up the power feeding the ADATs.
CHECKING SOFTWARE VERSION
To show the current operating software version in the TIME counter, hold SET LOCATE and press FAST FWD.
Appendix B - Troubleshooting

TROUBLESHOOTING INDEX

If you experience problems while operating the LX20, please use the following table to locate possible causes and solutions before contacting Alesis customer service for assistance.

Symptom

The display does not light when the POWER switch is turned on. FORMAT indicator flashes. The record-enabled tracks meters do not indicate input levels. Cant change the sample rate/clock source.

No power.

Solution
Check that the power cable is plugged in properly. Format the tape, or reinsert. Check your audio cables. Press ANALOG INPUT. Set the sample rate/clock source on the master LX20.
Tape is not formatted. Cables are not connected properly or are shorted. DIGITAL INPUT is selected. If slave in a multiple ADAT system, EXT clock is selected automatically. Locate Point 3s position is before Locate Point 2. Locate Point 4s position is before Locate Point 1. No ADAT master is detected. Edit mode is turned on. One or more errors have been detected/corrected Tape was formatted at different sample rate than currently selected. Several possible
Pressing AUTO REC displays invALid. AUTO RETURN indicator flashes. When used as a slave in a multiple ADAT system, doesnt follow the master. TIME counter does not show tape position. Interpolation indicator ( ) lights/flashes. 48K or 44.1K indicator flashes. Error Message in display
Set Locate Point 3 past Locate Point 2. Set Locate Point 4 past Locate Point 1. Check sync cables. Power down the Master only, then restart. Press EDIT VALUE to turn Edit mode off. Clean the tape heads. Make a backup copy of your tape. If desired, press CLOCK SELECT to use original sample rate. See Appendix C: Error Codes

ERROR RATE DISPLAY

The TIME counter has a secondary mode which, when selected, will display only the minutes and seconds of the tape position, and the error rate while the transport is engaged in play or record. This error rate is viewed as a count of the number of sync block errors per 14 drum revolutions (every 280ms), up to a theoretical maximum of 6720 errors. Selecting this display mode during any other mode than play or record will always give a reading of 0000. To view the error rate display:
p Hold SET LOCATE and press RECORD ENABLE 3.
The TIME counter will briefly read:

d1 SP E rr

ADA8824 (ADAT) and ADA8824 (Sonic)
A perfectly transparent signal every time.
CONNECTING AT THE SPEED OF LIGHT.
Lightpipe, or fiber-optic, connections are becoming a popular standard for digital audio transfer. Its easy to understand why. Using multiple channels simultaneously is incredibly convenient, and the Alesis ADAToptical standard supports full 24-bit resolution. Alesis pioneered the use of fiberoptic connections for digital audio transfer through its proprietary format. The Alesis PCR card works on Macintosh and Windows computers and is compatible with products from a wide range of vendors. The growing popularity of ADAT-equipped gear and the introduction of Lucids ADA8824 (ADAT) make it even easier for you to stay in the digital domain throughout most of the production process.
Get the performance you need for leading-edge music production and post-production with an audio interface that provides an immaculate connection between your digital and analog gear. Two versions of the ADA8824 are available one for ADAT-optical lightpipe gear and one for SonicStudio workstations from Sonic Solutions. Both units transfer eight channels of I/O simultaneously with 24-bit resolution. And digitally controlled attenuation of analog inputs and outputs with high-resolution LED metering help you realize your maximum dynamic range.
Geared to your needs. Using the ADA8824, you can turn your computer into a full-blown professional recording workstation, regardless of which console or recorder you use. The ADAT version of the ADA8824 integrates seamlessly with all your ADAT lightpipe-equipped digital audio gear, including mixers, recorders, and computer interface cards, such as the Alesis ADAT-PCR. Using this fiber-optic connection, you can transfer multiple channels of data more easily and cleanly than ever before. If your studio uses SonicStudio workstations, you can get the same elegant interface using the Sonic version of the ADA8824. We designed this unit in close collaboration with Sonic Solutions engineers, so the box is fully compatible with their hardware and software.
ADA8824 (ADAT) Key Features
Eight analog I/O channels and eight digital I/O channels, with precision metering of analog and digital I/O Full 24-bit A/D and D/A resolution Digitally controlled, precision analog I/O gain control ADAT-optical I/O and ADAT-sync I/O connectors
ADA8824 CAPABILITIES Multiple channels for maximum flexibility. The ADA8824 provides eight channels of 24-bit A/D and D/A conversion, eight channels of AES/EBU I/O, and two channels of S/PDIF I/O. If you want more than eight channels of digital and analog I/O and you have the required software and computer speed, simply add more ADA8824s. Far-ranging dynamics. The ADA8824s 24-bit resolution provides the utmost in quality and clarity. Its over-sampling 24-bit A/D technology produces 113dBu (A-weighted) of dynamic range, providing the sonic detail required by leading producers and engineers. Remote control. The ADA8824 is the only product of its kind featuring digitally controlled analog attenuators on both inputs and outputs, so you can adjust operating levels from your computer screen via a graphical user interface. In addition, fifteen segment LED meters on the front panel of the ADA8824 provide multi-color level displays of analog and digital inputs and outputs. Flexible sync options. Your internal A/D sample rate can be set at either 48kHz or 44.1kHz. The ADA8824 can also be locked to an external AES reference signal or Word Clock. For D/A conversion, the ADA8824s circuitry automatically locks to the sample rate of the incoming digital bit stream. Use your connections. The ADA8824s balanced connectors provide the immunity to RFI that professionals demand. The analog and AES/EBU connections both use XLRs, and there are two USP ports for use with Sonic Solutions-compatible hardware. In addition, you can drive analog inputs of any impedance using the balanced XLR output jacks.

A VITAL PART OF YOUR SONICSTUDIO SYSTEM.
The ADA8824 is a required component of SonicStudio digital audio workstations using the SonicStudio 1624 card. These workstations are the product of choice for major recording labels, mastering studios, and CD plants around the world. Their unique combination of sound quality, precision, and productivity makes it easy for you to achieve exceptional, distinctive sound. The ADA8824 is compatible with SonicStudio software accessories and add-on application modules, such as Studio Suite, CD Mastering Suite, Audio Post Suite, and NoNOISE Production Suite.
ADA8824 (Sonic) Key Features
Eight analog I/O channels and eight digital I/O channels, with precision metering of analog and digital I/O Full 24-bit A/D and D/A resolution Digitally controlled, precision analog I/O gain control Works with Sonic Solutions digital audio workstations using the SonicStudio 1624 card
S P E C I F I C A T I O N S
ADAT SYNC IN CONFIGURATION
REFER TO USER'S GUIDE FOR OPTIONS 7 8
AES/EBU DIGITAL INPUTS OUT MIDI

ANALOG INPUTS

ADAT OPTICAL

INPUT OUTPUT

OUT/THRU

ADA8824

AC INPUT 40 WATTS MAXIMUM

WORD CLOCK

S/P DIF AES/EBU DIGITAL OUTPUTS ANALOG OUTPUTS
MANUFACTURED IN LYNNWOOD, WA, USA NO USER SERVICABLE PARTS INSIDE

OUTPUT

ADA8824 (ADAT) Multi-Channel Audio Interface
Analog-to-digital performance
THD+Noise: <0.005% Frequency response: 20Hz 20kHz (+/-0.5dB) Dynamic range: >105dB, A-weighted Analog output impedance: 320 balanced Maximum analog output level: +25dBu balanced

Connectors

MIDI connectors: 2 x DIN5 Word Clock connector: BNC

Physical

Conversion: 24-bit delta/sigma Signal-to-noise ratio: >113dBFS, A-weighted THD+Noise: <0.005% Frequency response: 20Hz 20kHz (+/-0.5dB) Dynamic range: >113dB, A-weighted Analog input impedance: 20k balanced Maximum analog input level: +25dBu balanced (+/-1dB)
Digital-to-analog performance
2U chassis: 3.469(H) x 19(W) x 8.5(D)
ADAT-optical compatible hardware
Alesis ADAT Type II Systems: XT20, LX20, M20 Fostex D160 Hardisk Recorder Yamaha 02R Digital Mixer
ADAT-optical compatible audio cards
Analog input and output connectors: 8 x balanced XLR Digital input and output connectors: 4 x AES/EBU XLR and 1 x S/PDIF RCA/coaxial ADAT connectors: 2 x ADAT-optical, 2 x ADAT sync (DB9)
Conversion: 24-bit delta/sigma Signal-to-noise ratio: >105dBFS, A-weighted
Alesis-PCR Sonorus STUDI/O Korg 1212 I/O SEKD ProDif Gold Frontier Designs Montana, Dakota
SONIC SOLUTIONS INTERFACE MODULE CONFIGURATION
POS. 1-1 FUNCTION UP DOWN UNIT# 1 O S RATE 48K 44.1K M TYPE ANA DIG IN OUT M SEL 8

AES/EBU DIGITAL INPUTS

SONIC I/O

S/P DIF

AES/EBU DIGITAL OUTPUTS

ANALOG OUTPUTS

ADA8824 (Sonic) Multi-Channel Audio Interface
Analog-to-digital performance Digital-to-analog performance Connectors
Conversion: 24-bit delta/sigma Signal-to-noise ratio: >105dBFS, A-weighted THD+Noise: <0.005% Frequency response: 20Hz 20kHz (+/-0.5dB) Dynamic range: >105dB, A-weighted Analog output impedance: 320 balanced Maximum analog output level: +25dBu balanced
Analog input and output connectors: 8 x balanced XLR Digital input and output connectors: 4 x AES/EBU XLR and 1 x S/PDIF RCA/coaxial Sonic USP connector: 2 x 68-pin SCSI-3 Word Clock connector: BNC
Compatible digital audio I/O card

SonicStudio 1624