Front Panel Controls And Jacks; Mic Preamp Controls; Instrument Input; Gain Control - Art PRO CHANNEL II Service Manual

FRONT PANEL CONTROLS and JACKS

Mic Preamp Controls

The Pro Channel II input consists of a discrete Class-A differential preamp. The circuit is optimized
for low impedance microphones as well as line level signals. Up to 56dB of gain is available from this
stage. The output can be inverted using the INVERT switch.
The impedance of the rear XLR input is continuously variable for fine-tuning the preamp to a wide
variety of mics. Phantom power is available on the XLR input as well.
A selectable low-cut filter removes rumble, wind noise, and pops, thereby increasing clarity.

Instrument Input

The 1/4-inch T/S jack on the front panel provides a high impedance unbalanced input, and when
used, automatically switches off the mic pre-amp. (The rear XLR balanced input is lower impedance
and is part of the mic pre-amp. The rear jack is not intended to be used with high impedance
microphones or instruments.)

Gain Control

This control adjusts both the mic pre-amp gain as well as the instrument input gain. The gain
marked applies to the mic pre-amp without the GAIN switch depressed. Refer to the APPLICATIONS
section to learn how to optimize the gain control for low noise operation.

Impedance Control

This knob sets the load impedance at the rear panel XLR input of the Pro Channel II. Use the
IMPEDANCE CONTROL to subtly tune the sound of your microphone. Various microphones will
change their sound at differing load impedances. The correct setting is subjective. Adjust this control
to personal taste.
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