Alesis ADAT-XT manual Record Enable, Setting Levels

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Basic Operations: Chapter 4

RECORD ENABLE

To record enable a track, press the track’s RECORD ENABLE button.

When you press a track’s RECORD ENABLE button for the first time, the track’s red REC LED will flash, indicating the track is in record-ready, and its INPUT LED will light (unless Auto Input is on and the transport is in play), indicating you will be able to monitor that track’s input. If the transport is put into record mode (see Transport Controls in this chapter), recording will begin on this track; the track’s REC LED will stop flashing and remain lit. To disable record-ready, press the track’s RECORD ENABLE button once again. The track’s REC LED will turn off.

RECORD ENABLE buttons can be turned on or off while you are in record mode.

SETTING LEVELS

Unlike analog tape recorders, where signals routinely exceed 0 dB with no apparent ill effects, 0 dB on the XT represents the maximum possible signal level . Signals above 0 dB will be clipped and lead to digital distortion.

Because of the limitations of analog tape, there is always a tradeoff between noise, level and distortion. More level improves the signal-to-noise ratio, but also increases distortion. This distortion increases linearly, which is why signal-to-noise is often specified for a certain amount of distortion (typically 3%). You can always record with hotter levels or softer levels, but either more distortion or more noise will result—with analog, you can’t have low noise, high levels and low distortion.

With digital recording, there is a much wider dynamic range, and distortion does not increase with increasing level. Yet once a digital system runs out of headroom and hits 0 dB, that’s it—the onset of distortion is immediate and very noticeable if the signal is sustained several dB above the limit. Even though very short peaks above 0 may not last long enough to cause audible distortion, you aren't capturing the signal in its original form. As a result, because of the XT’s signal to noise characteristics, it’s better to err on the side of setting levels not quite high enough rather than having them distort, especially during live recording when you don’t get a second chance. In the studio, where you have more control over levels or are using compressor/ limiters, it’s OK to light up the MAX LED on the meter on the very loudest peaks, as long as you're sure that signals aren't going beyond that point (by using the meters on your console, if they go beyond +15 dB).

 

However, since 0 dB on the XT equals the maximum level, the input reference level is

 

set below 0 VU. With the XT, a 0 VU signal on a +4 dBu mixer plugged into the XT’s

 

+4 dBu connectors (or a 0 VU signal on a -10 dBV mixer plugged into the XT’s -10

 

dBV connectors) will register -15 dB on the XT’s meters. Therefore, you can run the

 

mixer over 0 VU and still have 15 dB of headroom on the XT before distortion occurs.

 

Just remember that no matter what, if the XT’s meters indicate over 0 dB, distortion is

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occurring or is on the verge of occurring.

Be sure the output level of your mixer matches the inputs connected to the XT (+4 or

 

-10).

ADAT XT Reference Manual

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Contents Alesis ADAT-XT Introduction Adat XT Reference Manual Conventions Adat XT Reference Manual Contents Basic Operations Analog Recording Basics Digital Recording Basics Why S-VHS? Index Maintenance/Service Cleaning Obtaining Repair Service AC Power Hookup Setting UPUnpacking and Inspection ChapterSetting Up Line Conditioners and Protectors About Audio CablesInput Normaling Basic Audio HookupWord on ADAT’S S-VHS Cassette Tape Threaded VS. UnthreadedThermal Considerations in Rack Mounting Operating EnvironmentMounting on a Shelf or NON-RACK Enclosure Avoiding Electromagnetic InterferenceYour First Session POWER-UP,AND Tape InsertionABS 0H 15M 48S ABS n0 F0Sample Rate Selection Formatting a Tape a MustFormatting a NEW Tape Recording While FormattingTo record-enable a track Track Selection and Setting LevelsREL 0H 01M 29S Making a RecordingRecording Transport ButtonsTo make a recording Record LED turns off, while the Play LED remains litTo engage Cue mode To engage Review modePlayback Reviewing and CueingLocating REL 0H 00M 00SPage To loop a section of tape Creating a LoopRehearsing Automated RecordingTo automatically punch in and out Measure twice or more, and cut only onceABS 00 % 00 C Track Delay70 mS Pitch ControlTrack Copy To adjust the display brightnessDisplay Brightness To bounce audio from one track to anotherConnections Input Jack CharacteristicsAnalog Audio Unbalanced Inputs Analog Audio Unbalanced OutputsAdditional grounds Analog Audio Balanced Inputs and OutputsInput Mode Analog Audio Input ModeTo synchronize multiple XTs and/or ADATs Sync IN/OUTTo connect the digital optical network Digital Audio IN/OUTRehearse and Auto Record features FootswitchesXT Remote VersaTape Formatting Basic OperationsFormatting Considerations Complete FormatBe sure the tape is completely rewound Format ExtendABS Pr 0t 0 n ABS Pr 0t 0 FFWrite Protect Override To extend the format on a partially formatted tapeReading the Display Display Icons Basic Operations Time Counter & ABS/REL Button 01M 29SLocate SelectedEdit Value Button Basic EditingEntering Numeric Values Editing Individual DigitsAnalog Input Input SelectDigital Input Track CopyBasic Operations Input Monitor Auto Input MonitorALL Input Monitor Fine Meter Mode Peak Mode ButtonMeters Recording a Benchmark T APESetting Levels Record EnableEject Transport ControlsRewind /REVIEW Fast Forward /CUEStop RECORD/PUNCH in or OUTWhether the tape being played is formatted or not To start recordingRecord Crossfade Time Sample Rate ClockPositions as before To select the sample rateFA dE 2 Displaying Frames VS THS/SECONDSTo set the Crossfade Time About Pitch Changing To set the Track Delay amount To turn Track Delay on and offTo set multiple tracks to the same Track Delay value 10 mSAutolocation Controls Absolute ABS Time VS . Relative TimeLocate Locating Setting Locate PointsTo store a Locate Point memory on the fly To edit a Locate Point memoryAuto Return Auto LoopingAuto Play Loop LimitTape Length Auto RecordLooped Recording RehearsalTo set the tape length European equivalents and approximate recording timesErroneously selected, to avoid damage to the tape Footswitch Controls Footswitch Controlled PunchingFootswitch Controlled Autolocating Using the XT Remote Operation OverviewSynchronizing Machines Achieving Lock Master /SLAVE InteractionMaster Format ENABLED, Complete Format Independent Slave ModeMaster Format ENABLED, Format Extend Formatting Multiple TapesMaster Format Disabled Master Format DISABLED, Format ExtendBefore punching into format record Recording Digital Audio Making Digital BackupsBouncing Tracks Between Adats Reassigning Channels to Different TracksRecording Digital Audio from Other Sources To make a backup tapeDigital Clock Considerations Tape OffsetABS 0H 00M 00S Setting the Machine OffsetXT Transport Speed Combining XTS and AdatsSample Rate VS. Pitch Control Input MonitoringHere are some possible solutions Polarity DifferencesConnections Multiple ADAT-XT Operation Chapter Multiple ADAT-XT Operation Adat XT Reference Manual Combined MULTITRACK/MASTERING Deck ApplicationsLIVE/LONG-TERM Recording Locking to Video Code only Master Midi Machine Control Virtual Remote ControlComputer Control Midi Systems Virtual TrackingModular Recording Libraries and ArchivesCalculating Tape Offset Using the Locates Using Track Copy AS a Digital RouterPress Edit VALUE, then press Locate Analog Recording Basics Digital Recording ConceptsDigital Recording Basics Appendix aWHY S-VHS? TROUBLE-SHOOTING Index TroubleshootingRE-INITIALIZING Appendix BAbout Error Rate Readings Error Rate DisplayABS d1 SP E rr ABS d1 SP r E9Adat Head Maintenance MAINTENANCE/SERVICE Tape Maintenance Safe TapeCleaning Drum Time DisplayObtaining Repair Service MaintenanceRefer ALL Servicing to Alesis Customers in the USAAppendix B Troubleshooting Appendix C Error CodesAutomatic Brake Calibration Procedure Specifications Steps to Take Before Calling for HelpAppendix D Audio Digital Inputs/Outputs Or Analog-to-Digital Converter GlossaryDAT BusMMC MidiSMPTE/LTC OutputVitc VHSIndex Index Adat XT Reference Manual