PageF-5
X-Rack Master Module
F.5 Calibration Information
The X-Rack Master module is factory calibrated and should only need calibration if a potentiometer or
other component has been replaced or if it is suspected that thereis a problem with calibration.
In each of the following instructions it is assumed that the lid of the X-Rack has been removed and that
power has been applied. It is also assumed that, unless otherwise specified, all switches are released and
allfront panel potentiometers are at unity or minimum position as appropriate. The required accuracy for
each adjustment will be specified along with the target value. All level and distortion measurements
should be made with audio-band 20Hz to 20kHz filters unless otherwise specified.
All presets areaccessible from the top of the unit.
F.5.1 Mix Level Tracking
Equipment Required: Calibrated audio oscillator and audio level meter
TestSignal: 1kHz sinewave @ +24dBu
Input and Output: Oscillator to Insert Return Left
Output to the audio level meter from Mix Bus Output (use Left or Right
as instructed below)
Unit Setup: Select‘INS’ and set ‘MIX LEVEL’to centre.
Adjustment: 1. MeasureMix Bus Output Left and note the reading.
2. Connectthe oscillator to Insert Return Right.
3. MeasureMix Bus Output Right and adjust VR6 (‘TRACKING’) for a level
which matches that measured in step 1.
F.5.2 Meter Level
Equipment Required: Calibrated audio oscillator and audio level meter
TestSignal: 1kHz sinewave @ +24dBu
Input and Output: Oscillator to Insert Return Left
Output to the audio level meter from Follow Mon Output (use Left or
Right as instructed below)
Unit Setup: 1. Select‘INS’ and set ‘MIX LEVEL’ to maximum.
2. Select
Adjustment: 1. Measure the Left ‘Follow Mon’ Output. Adjust the oscillator level to
obtain +24dBu, if necessary.
2. AdjustVR5 (‘0dB LEFT’) so that that the top left hand ‘red’ LED on the
bargraph meter just illuminates.
3. Connectthe oscillator to Insert Return Right.
4. Measure the Right ‘Follow Mon’ Output. Adjust the oscillator level to
obtain +24dBu, if necessary.
5. AdjustVR4 (‘0dB RIGHT’) so that that the top right hand ‘red’LED on the
bargraph meter just illuminates.