AMX AutoPatch Modula, Instruction Manual, Page: 117 / 191

Mono Audio Boards
111 Modula Instruction Manual
Adjusting Input Gain
For mono audio boards that support input gain, adjustments (within the gain range for the specific audio
inputs) are normally made during system setup; however, they can be made at any time during normal
operation. When audio is adjusted for a device, the adjustment applies to all levels switching audio
signals. Mono input boards are set to unity gain at the factory.
Caution: We strongly recommend that input gain adjustment be made only by a qualified installer or
dealer.
Purpose and Uses of Input Gain
The purpose of controlling input gain (the nominal level of the signal from the source device) is to allow
source signals of various amplitudes to be equalized before they are routed and the volume is adjusted.
Equalizing source levels provides a consistent reference for volume adjustments and eliminates jumps
when routing a new source to a destination.Typical uses for input gain include switching consumer and
professional grade audio equipment (whose levels can vary noticeably) in the same matrix switcher.
Input gain adjustment is also used for equalizing amplitudes between balanced and unbalanced sources.
To equalize input levels by adjusting input gain:
1.
Route a source (input) to the first destination (output).
2.
Adjust the input gain for the source to the desired dB level (see below).
3. Repeat for all sources that will be routed to the same destination.
Potentiometer Input Boards
Mono audio input boards are set to unity gain at the factory.
To use potentiometer input gain to equalize input levels:
1.
Route a source (input) to the first destination (output).
2. Adjust the input gain for the source to the desired dB level by turning the corresponding
potentiometer (FIG. 70) clockwise (to the right) to decrease gain, counterclockwise (to the left) to
increase gain.
3.
Repeat for all sources that will be routed to the same destination.
FIG. 70
Input gain adjustment pots
Channel 1
Channel 2
Channel 3
Channel 4