Optimizing The Preamp For Lowest Noise - Art PRO CHANNEL II Service Manual

APPLICATIONS
Bypassing Components Of The Pro Channel II
To bypass the vacuum tube microphone preamp: Use the preamps INSERT INPUT jack instead
of the Instrument or Mic input jack.
To bypass the Compressor/Limiter: Use the COMP bypass switch.
To bypass the EQ: Use the EQ bypass switch.

Optimizing The Preamp For Lowest Noise

The preamp of the ART Pro Channel II can be optimized for low noise by combining use of the PAD
and Input GAIN control for mic and line level signals. NOTE: The PAD control has no effect on the
INSTRUMENT INPUT (Front panel 1/4-inch input of the INPUT combo jack).
First, bypass the Compressor/Limiter, Expander/Gate and EQ. Next center the OUTPUT LEVEL
control to "0" dB of gain. The OUTPUT LEVEL LED meter can now be used to correctly indicate the
clip level of the input stage.
Second, start with the PAD in the "OUT" position and the GAIN control centered. Refer to the
OUTPUT LEVEL LED meter's peak-hold function. Make sure that this meter never indicates clipping
(the red LED is held on after a transient). The peak-hold indicator can be in the "yellow" range or in
the –5dB range of levels.
If the signal level is too high, depress the PAD switch.
Third, adjust the GAIN control to keep the peak levels in the –5dB range of the OUTPUT LEVEL
LED meter.
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