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X-Rack Owner’sManual
E.5 Calibration Information
The X-Rack Line Return 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 an X-Rack Master module is also fitted to the
X-Rack and that power has been applied. It is also assumed that unless otherwise specified, all switches
are released and all front 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.
These presets are not accessible fromthe top of the unit, access to the right-hand side of the module will
be requiredfor adjustment.
E.5.1 Line Input
Equipment Required: Calibrated audio oscillator and audio level meter
TestSignal: 1kHz sinewave @ 0dBu
Input and Output: Oscillator to Line Input
Outputto the audio level meter from Master module Mix Bus Insert Send
(use Left or Right as instructed below)
Unit Setup: 1. Seteach Level control to indent (0dB).
2. Seteach Pan control Left.
E.5.2 Line 1
Adjustment: 1. MeasureInsert Send Left and adjust VR9 for 0dBu ±0.1dB.
2. Setthe Pan control to Centre and adjust VR14 for –4.5dBu ± 0.1dB.
3. MeasureInsert Send Right and adjust VR13 for –4.5dBu ± 0.1dB.
4. Repeateach step until correct.
E.5.3 Line 2
Adjustment: 1. MeasureInsert Send Left and adjust VR10 for 0dBu ± 0.1dB.
2. Setthe Pan control to Centre and adjust VR16 for –4.5dBu ± 0.1dB.
3. MeasureInsert Send Right and adjust VR15 for –4.5dBu ± 0.1dB.
4. Repeateach step until correct.
E.5.4 Line 3
Adjustment: 1. MeasureInsert Send Left and adjust VR11 for 0dBu ± 0.1dB.
2. Setthe Pan control to Centre and adjust VR17 for –4.5dBu ± 0.1dB.
3. MeasureInsert Send Right and adjust VR18 for –4.5dBu ± 0.1dB.
4. Repeateach step until correct.
E.5.5 Line 4
Adjustment: 1. MeasureInsert Send Left and adjust VR12 for 0dBu ± 0.1dB.
2. Setthe Pan control to Centre and adjust VR19 for –4.5dBu ± 0.1dB.
3. MeasureInsert Send Right and adjust VR20 for –4.5dBu ± 0.1dB.
4. Repeateach step until correct.