X2 X2 manual Avoiding Ground Loops, To Eliminate HUM if the Above has Failed

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Connecting the X2

Avoiding Ground Loops

In today’s studio, where it seems every piece of equipment has its own computer chip inside, there are many opportunities for ground loop problems to occur. These show up as hums, buzzes or sometimes radio reception and can occur if a piece of equipment “sees” two or more different paths to ground. While there are methods to virtually eliminate ground loops and stray radio frequency interference, most of the professional methods are expensive and involve installing a separate power source just for the sound system. Alternatively, here are some easy helpful hints that a professional studio installer might use to keep those stray hums and buzzes to a minimum.

1KEEP ALL ELECTRONICS OF THE SOUND SYSTEM ON THE SAME AC ELECTRICAL CIRCUIT. Most stray hums and buzzes happen as a result of different parts of the sound system being plugged into outlets of different AC circuits. If any noise generating devices such as air conditioners, refrigerators, neon lights, etc., are already plugged into one of these circuits, you then have a perfect condition for stray buzzes. Since most electronic devices of a sound system don’t require a lot of current (except for power amplifiers), it’s usually safe to run a multi-outlet box or two from a SINGLE wall outlet and plug in all of the components of your system there.

2KEEP AUDIO WIRING AS FAR AWAY FROM AC WIRING AS POSSIBLE. Many hums come from audio cabling being too near AC wiring. If a hum occurs, try moving the audio wiring around to see if the hum ceases or diminishes. If it’s not possible to separate the audio and AC wiring in some instances, make sure that the audio wires don’t run parallel to any AC wire (they should only cross at right angles, if possible).

3TO ELIMINATE HUM IF THE ABOVE HAS FAILED:

A)Disconnect the power from all outboard devices and tape machines except for the X2 mixer and control room monitor power amp.

B)Plug in each tape machine and outboard effects device one at a time. If possible, flip the polarity of the plug of each device (turn it around in the socket) until the quietest position is found.

C)Make sure that all of the audio cables are in good working order. Cables with a detached ground wire will cause a very loud hum!!

D)Keep all cables as short as possible, especially in unbalanced circuits.

If the basic experiments don’t uncover the source of the problem, consult your dealer or technician trained in proper studio grounding techniques. In some cases, a “star grounding” scheme must be used, with the X2 at the center of the star providing the shield ground on telescoping shields, which do NOT connect to the chassis ground of other equipment in the system.

X2 Reference Manual

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Contents Alesis Conventions How To Use This ManualIntroduction Description of Controls. a dictionary of each controlX2 Reference Manual Contents Applications Description of Controls Trouble-Shooting Midi Implementation Chart Page Introduction AboutRecording/Tracking Basic Principles of Mixing & Multitrack RecordingMonitoring Mixdown Introduction X2 Reference Manual Guided Tour Recorder/Mix SystemsPage Aux Send/Return Systems Muting Automation Control Room SystemsMeter Bridge Page Page Connections PowerPower Supply Unpacking and InspectionTo connect the power supply to Avoiding Ground Loops To Eliminate HUM if the Above has FailedBalanced Mic Inputs Channel Inputs and OutputsUnbalanced Line Inputs Page Tape Send Direct Output +4/-10 SwitchTape Input InsertBalanced Tape I/O To connect an Elco cable toGroup Inserts Stereo Returns and GroupsGroup Outputs Aux a & B ReturnsMaster Inserts Master Inputs and OutputsMaster Outputs Control Room OutputsPage Adat Sync HeadphonesTo synchronize the X2 to an Adat system Input Connector Type Examples of ConnectionsInterfacing to an Unbalanced -10 dBV Multitrack Recorder To interface with a typical unbalanced multitrack recorderInterfacing to a Professional +4 dBu Multitrack Recorder Interfacing to the Mixdown Deck Interfacing to Adat Using Elco ConnectorsInterfacing to a Multitrack Recorder via a Patchbay To connect the mixdown deck toInterfacing to the Headphone Amp Interfacing to the Control RoomInterfacing to the Studio Interfacing Aux Sends and Returns to Outboard EffectsConnecting Simultaneously, if desired Interfacing with a Midi Sequencer Interfacing the InsertsTo interface a Midi sequencer with Recording Setting LevelsApplications II. Maintain Proper Fader LevelsRecording a Single Source to One Track To record a single source to a single trackRecording Multiple Sources to One Track To record two or more sources to a single trackRecording Multiple Sources to Two Tracks Stereo To record multiple sources to two tracks stereoRecording Tips To select the meter bridge modeAbout Metering To listen to tape tracks on the Monitor faders OverdubbingTo listen to tape tracks on the Channel faders Applications Previous section X2 Reference Manual Monitoring Midi Virtual Tracks Getting the Mix to the HeadphonesTo route the mix to a headphone amp Selecting an Aux Send Adding EffectsTo set the level going to the effects device To hear effects in the headphone/cue mix To hear effects in the monitorsTo record effects onto the multitrack To bounce one or more tracks to another track mono Bouncing TracksTo record effects onto the mixdown deck To bounce multiple tracks to two tracks stereoGetting the Mix to the Tape Deck Playback/Mix-DownMixdown Basics Here is a simplified step-by-step way to establish a mixCreating a Dependable Mix To create a dependable mixMute Automation Page Live Performance Using Group Faders as SubgroupsTo configure the X2 mixer in order to achieve a mono mix Creating a Monitor MixStage Monitor Mix Video Post-ProductionTo create two different stage monitor mixes Applications X2 Reference Manual Mute Automation OverviewDestructive Solo To enable destructive solo modeMute Groups Page Defining Mute Groups To define Mute GroupsTo recall a Mute Group Recalling Mute GroupsOverlay Button To return the console to its previous mute statusSelecting a Sync Source Display ModeSynchronization Getting On-line/LockingUndoing Mute Events Mute EventsRecording and Playing Back Mute Events OverdubbingPage Editing Songs ErasingTo erase all events on all channels Erase All MemoryTo erase all events on one or more channels To erase a Song including its mute events and 4 Mute GroupsCopy Song CopyingCopy Mute Events To copy mute events from one channel to anotherSelecting Songs via Midi Midi ChannelTo set the Midi channel Midi Map Receiving System Exclusive Memory BackupTransmitting System Exclusive Remaining MemoryDescription of Controls Input Channel ControlsHi and Lo EQ HPF SwitchTo MON Switch Hi Mid and Lo Mid EQAUX Source Switch EQ in SwitchSwitch Aux 3/4 AUX 1-2, AUX 1-2 PANMonitor Peak LED Switch Aux 5/6Monitor PAN Monitor Solo ButtonChannel PAN DIR SwitchGroup Assign Switches 1-2, 3-4, 5-6 Channel Peak LEDAux Master Controls Stereo Aux Return ControlsStereo Separation AUX a Assign Switches Aux a OnlyGroup Masters Switch Aux B Only BalanceSolo Button Group Master ControlsButton Mute ButtonGroup 1-8 Master Faders Solo LED and Level Master ControlsOscillator Frequency and Level Studio Level and AssignmentMaster Faders PhonesControl Room Level and Source Meter BridgePage Mute Automation Controls DisplayMute Groups Online Erase FWD and Erase BWD Buttons Memory RemainingErasing Memory Mute SoloDescription of Controls X2 Reference Manual Checking the Software Version TROUBLE-SHOOTINGTrouble-Shooting Index Re-initializingWarranty Information Maintenance/ServiceCleaning and Maintenance Obtaining Repair ServiceCustomers outside the USA Trouble-Shooting X2 Reference Manual Maps Midi Maps IndexMute Midi Note Number Map Mute Midi Controller NumberMap Number Interval Midi Implementation Chart Specifications Input Module Power SupplyMaximum Gain Group ModuleTotal Shipping Weight DimensionsWeight Dimensional DrawingsInternal Connector Pinouts Block Diagram Index SoloSong LED 102
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