PageK-6
X-Rack Owner’sManual
4. Switch BLK in and re-adjust LMF Frequencyfor maximum level.
5. Adjust VR16 for +18dBu ±0.25dB.
6. Reset LMF Gain to its centre indent position and releasethe BLK switch.
Re-check the audio level meter for 0dBu.
LF EQ – Maximum Gain
Adjustment: 1. Ensure that the BLK switch is released.
2. Set LF Gain to maximum and select LF BELL. Set the audio oscillator for
80Hz and adjust LF Frequency to find the maximum level on the audio
level meter.
3. Adjust VR17 for +15dBu ±0.25dB.
4. Switch BLK in and re-adjust LF Frequencyfor maximum level.
5. Adjust VR18 for +18dBu ±0.25dB.
6. ResetLF Gain to its centre indent position, release the BLK switch and de-
select LF BELL. Re-check the audio level meter for 0dBu.
K.4.2 OutputBalance
Equipment Required: Calibratedaudio oscillator, audio level meter and a ‘balance’ adaptor (see
below).
TestSignal: 1kHz sine wave at +24dBu.
Input andOutput: Oscillator to the Input of the channel being tested, Output to the level
meter via the ‘balance’ adaptor.
Unit Setup: Ensure that all front panel switches are off and all controls areset fully
anti-clockwise.
Adjustment: Connect the test equipment to the each channel in turn and adjust VR19
(BAL) for minimum level (< 55dBr).
K.4.3 ‘Balance’Adaptor
For the output balance adjustment, a ‘balance’
adaptor such as that illustrated here will be
required. This adaptor consists of a pair of
close tolerance resistors in an in-line cable and
is used to sum together a balanced output in
orderto correctly adjust the level balance of the
measuredoutput; perfect balance should result
in complete signal cancellation.
5K01**
5K01**
2
3
1
2
3
1
0V
+
–
0V
+
–
To measuring
equipment
From unit
under test
1
2
1
Resistor tolerance should ideally be 0.01%
Absolute level measured will depend upon the input
impedence of the measuring equipment.
1.
2.
Note