Alesis ADAT-XT manual Setting Up

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Chapter 1: Setting Up

buzzes, or sometimes radio reception and can occur if a piece of equipment “sees” two or more different paths to ground, as shown below.

Device A

shielded

cable

path 1

Device B

path 2

To AC power service

One path goes from device A to ground via the ground terminal of the three- conductor AC power cord, but A also sees a path to ground through the shielded cable and AC ground of device B. Because ground wires have a small amount of resistance, small amounts of current can flow through ground and generate a voltage along the cable shield. This signal may end up getting induced into the hot conductor.

The loop can also act like an antenna into which hum is induced, or can even pick up radio frequencies. Furthermore, many components in a circuit connect to ground. If that ground is “dirty” and contains noise, it might get picked up by the circuit. Ground loops cause the most problems with high-gain circuits, since massive amplification of even a couple millivolts of noise can give an audible signal.

Most ground loop problems can be solved by plugging all equipment into the same grounded AC source. However, it is important to make sure that the AC source is not overloaded and is properly rated to handle the gear plugged into it.

For really tough cases, you may need to break the connection that causes the loop condition. One way to do this is to simply break the shield of the shielded audio cable at some point, usually by disconnecting it from ground at one jack. (The other end should remain connected so that the shielding properties are retained, even if there is no direct path for ground.)

Please note that not all hums and buzzes are caused by ground loops; your cables must be of very high quality, particularly with -10 dBV setups. Refer to section 2.1 for more information.

8	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 Chapter Setting UPAC Power Hookup Unpacking and InspectionSetting Up Line Conditioners and Protectors About Audio CablesInput Normaling Basic Audio HookupWord on ADAT’S S-VHS Cassette Tape Threaded VS. UnthreadedAvoiding Electromagnetic Interference Operating EnvironmentThermal Considerations in Rack Mounting Mounting on a Shelf or NON-RACK EnclosureABS n0 F0 POWER-UP,AND Tape InsertionYour First Session ABS 0H 15M 48SRecording While Formatting Formatting a Tape a MustSample Rate Selection Formatting a NEW TapeMaking a Recording Track Selection and Setting LevelsTo record-enable a track REL 0H 01M 29SRecord LED turns off, while the Play LED remains lit Transport ButtonsRecording To make a recordingReviewing and Cueing To engage Review modeTo engage Cue mode PlaybackLocating REL 0H 00M 00SPage To loop a section of tape Creating a LoopMeasure twice or more, and cut only once Automated RecordingRehearsing To automatically punch in and outPitch Control Track DelayABS 00 % 00 C 70 mSTo bounce audio from one track to another To adjust the display brightnessTrack Copy Display BrightnessAnalog Audio Unbalanced Outputs Input Jack CharacteristicsConnections Analog Audio Unbalanced InputsAdditional 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/OUTVersa FootswitchesRehearse and Auto Record features XT RemoteComplete Format Basic OperationsTape Formatting Formatting ConsiderationsBe sure the tape is completely rewound Format ExtendTo extend the format on a partially formatted tape ABS Pr 0t 0 FFABS Pr 0t 0 n Write Protect OverrideReading the Display Display Icons Basic Operations Selected 01M 29STime Counter & ABS/REL Button LocateEditing Individual Digits Basic EditingEdit Value Button Entering Numeric ValuesTrack Copy Input SelectAnalog Input Digital InputBasic Operations ALL Input Monitor Input MonitorAuto Input Monitor Recording a Benchmark T APE Peak Mode ButtonFine Meter Mode MetersSetting Levels Record EnableFast Forward /CUE Transport ControlsEject Rewind /REVIEWTo start recording RECORD/PUNCH in or OUTStop Whether the tape being played is formatted or notTo select the sample rate Sample Rate ClockRecord Crossfade Time Positions as beforeTo set the Crossfade Time FA dE 2Displaying Frames VS THS/SECONDS About Pitch Changing 10 mS To turn Track Delay on and offTo set the Track Delay amount To set multiple tracks to the same Track Delay valueLocate Autolocation ControlsAbsolute ABS Time VS . Relative Time To edit a Locate Point memory Setting Locate PointsLocating To store a Locate Point memory on the flyLoop Limit Auto LoopingAuto Return Auto PlayRehearsal Auto RecordTape Length Looped RecordingErroneously selected, to avoid damage to the tape To set the tape lengthEuropean equivalents and approximate recording times Footswitch Controlled Autolocating Footswitch ControlsFootswitch Controlled Punching Using the XT Remote Synchronizing Machines OperationOverview Achieving Lock Master /SLAVE InteractionFormatting Multiple Tapes Independent Slave ModeMaster Format ENABLED, Complete Format Master Format ENABLED, Format ExtendBefore punching into format record Master Format DisabledMaster Format DISABLED, Format Extend Reassigning Channels to Different Tracks Making Digital BackupsRecording Digital Audio Bouncing Tracks Between AdatsRecording Digital Audio from Other Sources To make a backup tapeDigital Clock Considerations Tape OffsetABS 0H 00M 00S Setting the Machine OffsetInput Monitoring Combining XTS and AdatsXT Transport Speed Sample Rate VS. Pitch ControlConnections Here are some possible solutionsPolarity Differences Multiple ADAT-XT Operation Chapter Multiple ADAT-XT Operation Adat XT Reference Manual Combined MULTITRACK/MASTERING Deck ApplicationsLIVE/LONG-TERM Recording Midi Systems Virtual Tracking Midi Machine Control Virtual Remote ControlLocking to Video Code only Master Computer ControlModular Recording Libraries and ArchivesCalculating Tape Offset Using the Locates Using Track Copy AS a Digital RouterPress Edit VALUE, then press Locate Appendix a Digital Recording ConceptsAnalog Recording Basics Digital Recording BasicsWHY S-VHS? Appendix B TroubleshootingTROUBLE-SHOOTING Index RE-INITIALIZINGABS d1 SP r E9 Error Rate DisplayAbout Error Rate Readings ABS d1 SP E rrAdat Head Maintenance Drum Time Display Tape Maintenance Safe TapeMAINTENANCE/SERVICE CleaningCustomers in the USA MaintenanceObtaining Repair Service Refer ALL Servicing to AlesisAppendix B Troubleshooting Appendix C Error CodesAutomatic Brake Calibration Procedure Appendix D SpecificationsSteps to Take Before Calling for Help Audio Digital Inputs/Outputs Or Analog-to-Digital Converter GlossaryDAT BusMMC MidiSMPTE/LTC OutputVitc VHSIndex Index Adat XT Reference Manual