Mackie Ultra-34, Руководство по обслуживанию

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VCA / DAC and Meter Test: VCA / DAC and Meter Test:
( Tests the voltage controlled amps. , their digital to analog converters and the meter circuitry) ( Tests the voltage controlled amps. , their digital to analog converters and the meter circuitry)
Action: Response:
This is a continuation of the IO Port Test.
Simultaneously depress the Local Mode and
Bypass switches.
This test ramps all of the VCAs up and down and runs the
meter multiplexer.
The local mode and bypass LEDs indicate the direction that
the VCAs are being ramped, with the Bypass LED indicating an
upward ramp and the Local Mode LED indicating a downward
ramp. The VCAs can be held at full gain by depressing the Bypass
switch or at full attenuation by depressing the Local Mode switch.
The VCAs will return to ramp mode when the switch is disengaged.
This test will also allow you to check the meter circuitry by
probing pin 3 of any 4051 IC on the VCA board. As long as the VCA
test is active, the meter multiplexer is running.
End of Test: End of Test:
(Good Bye) (Good Bye)
Action: Response:
This is a continuation of the VCA / DAC and
Meter Test.
Simultaneously depress the Local Mode and
Bypass switches.
Ends test and returns DUT to its normal operating mode.