dbx DriveRack 260, User Manual

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DriveRack
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DriveRack® 260 User Manual
31
Detailed Parameters
Section 4
4.5 Automatic Gain Control (AGC)
The AGC is used to keep the average level of a signal at a constant level. This is done by selecting a desired Target
output level and Window. The AGC keeps the signal within the Window about the selected Target by slowly adjusting
the gain. The maximum gain that can be applied to the signal is selected by the Gain parameter. When the input signal
falls below the Low Threshold the AGC releases the gain and returns to unity. This prevents the AGC from adding gain
when there is no signal present and raising the system noise floor. High level signals are reduced by a fast limiter to
prevent distortion by clipping. The AGC Threshold meters show what region of the AGC the input signal is in. The T
(yellow) indicates the signal is within the Window. A + (red) indicates the signal is going into the Limiter. A – (green)
indicates the AGC is adding maximum Gain and is at or below the Window. When the Threshold meter is off the signal
is below the Low Threshold.
AGC: On/Off
Turns the AGC module On and Off.
Target: (Targ) -20 to 20 dB
The Target parameter defines where you would like the average level of the AGC output to be. If the average level of
the signal rises above the Target the gain will be reduced. For signals with an average level below the Target the gain
will be increased.
Gain: 1 to 20dB
This adjusts the maximum amount of gain that can be added by the AGC.
Window: 1 to 10dB
This adjusts the amount of variation in the output
Low Threshold: -60 to -30dB
The Low Threshold sets a lower limit to the AGC. This prevents the AGC from adding gain to low level signals or noise.
Attack: 0.20 to 5 Seconds
Adjusts how fast AGC will reduce gain when the signal level is above target.
Release: 30.0 to 1 dB/Second
Adjusts the rate of gain increase when the signal level drops below target.