JBL 260 User Manual

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.

                           

Turns the AGC module On and Off.
 

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.
 

This adjusts the maximum amount of gain that can be added by the AGC.
 

This adjusts the amount of variation in the output 
 

The Low Threshold sets a lower limit to the AGC. This prevents the AGC from adding gain to 
low level signals or noise.

This adjusts how fast the AGC will increase gain.

This adjusts how fast the AGC will reduce gain.