Gain Controls - QSC CX168 User Manual

OPERATION:

Gain Controls

The gain controls are located on the right side of the front
panel. They are operated by rotating the control clockwise to
increase gain or counterclockwise to decrease gain. When
turned fully counterclockwise, gain is fully reduced and no
output signal will be present. When turned fully clockwise,
the voltage gain of the amplifier is +26dB and the output
signal will potentially be full strength (provided the input is
fully driven).
The gain controls are detented in 21 steps for repeatable
adjustment. Surrounding the Gain control, the power
attenuation level is shown in dB. Each detent is approxi-
mately 1dB change in amplifier gain.
To operate the gain control, rotate the control's knob so that
the desired level is achieved. A small, flat-tipped screw-
driver (#1 blade size) is typically used. Be sure not to use
large screwdrivers as it is possible to damage the gain
control by applying excessive torque. Gain controls are
sensitive, electronic components and should be treated with
care.
Each channel pair's gain controls and indicator LED's are
grouped together as shown, right. The channels are paired
in the following manner:
Channel Pair #1-
Channel Pair #2-
Channel Pair #3-
Channel Pair #4-
As detailed in the 'Setup' section of this manual, channels
can only be paralleled and bridged within their channel pair.
Example- Channel 3 can be bridged with channel 4 only; it
can not be bridged with any other channel.
The dB markings around the gain controls are attenuation.
They show attenuation from full gain. At 0db attenuation,
the voltage gain of the amplifier is 26dB. If the gain control
is set at the 7dB attenuation position, then the voltage gain
of the amplifier is 19dB (26dB - 7 dB).
18
GAIN CONTROLS
Ch. 1 and Ch. 2
Ch. 3 and Ch. 4
Ch. 5 and Ch. 6
Ch. 7 and Ch. 8
Location of gain controls on the front panel of the CX168
Typical channel-pair control and indicator group on the CX168
Typical gain control showing attenuation level
markings and LED's for the channel. Note that
there is only one BRDG (bridge) and one PAR
(parallel) indicator per channel pair.