Alto PBM4 SISTEMA, Руководство по обслуживанию

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MAIN OUT: –7dBu(±3dBu), distortion <0.05%.
MONTOR OUT LEFT: -2dBu(±3dBu), distortion <0.05%
FX SEND: –7dBu(±3dBu), distortion <0.003%
TAPE OUT: –7dBu(±3dBu), distortion <0.05%
(4) Test the output signal of CH5/6, when input mono signal to LEFT IN.
A. Set the LEVEL knobs of CH5~CH6 to the middle position
MAIN OUT: –21dBu(±3dBu), distortion <0.1%.
MONTOR OUT LEFT: -16dBu(±3dBu), distortion <0.1%
FX SEND: About -70dBu(±3dBu)
TAPE OUT: –21dBu(±3dBu), distortion <0.1%
B. Set LEVEL knobs of CH5~CH6 to the minimum.
MAIN OUT: About -60dBu(±3dBu), it should be no signal output.
MONTOR OUT LEFT: About –70dBu(±3dBu), it should be no signal output.
FX SEND: About -70dBu(±3dBu), it should be no signal output.
TAPE OUT: About –70dBu(±3dBu), it should be no signal output.
(5) Test the function of FX RETURN input and AUX/DFX RET knob.
A. Switch on DSP, set the AUX/DFX RET to the maximum
MAIN OUT: -29dBu(±3dBu), distortion <0.2%. Adjusting LEVEL knob, the output should be
changed accordingly
MONTOR OUT LEFT: -23dBu(±3dBu), distortion <0.2%. Adjusting MONITOR knob, the output
should be changed accordingly.
FX SEND: About -72dBu(±3dBu)
APE OUT: -29dBu(±3dBu), distortion <0.2%.
B. Switch on DSP, set the AUX/DFX RET to the minimum
No signal output on each channel
C. Switch on DSP, set the AUX/DFX RET to the middle position
MAIN OUT: -34dBu(±3dBu), distortion <0.3%.
MONTOR OUT LEFT: -29dBu(±3dBu), distortion <0.3%.
FX SEND: About -72dBu(±3dBu)
TAPE OUT: -35dBu(±3dBu), distortion <0.3%.
(6) Test the indicator of output level for MAIN OUT
Set the level of output signal for AP TO 10dBu. Connect the signal input of AP with MAIN OUT.
Set MAIN LEVEL from the minimum to the maximum. Inspect the output level on the computer during test,
the level that displays on the indicator of unit is in accordance with the level that displays on the computer.
The error is ±2dBu, the indicators light up in sequence from low to high. Don’t make mistake.
(7) Test the function of PAD switch, MIC jack, DSP switch, FOOT SW and DSP.
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