AGC OPERATION
ENG
Page 13
6.4 SETTING IDLE COMP, IDLE SPEED AND GATE THRESHOLD PARAMETERS
The two parameters IDLE Comp and IDLESpeed set the behaviour of AGC stage when the input signal is
‘silent’ or it falls under the Gate Threshold (see GateThr parameter).
The Idle Comp sets the Compression rate the AGC will reach when no signal is provided at the input.
The Idle Speed sets the AGC speed to reach that point.
Whit IdleSpeed = locked, the AGC freezes at its current status as soon as the input signal is removed or
drops under threshold.
It is advisable to set IdleComp = Drive
The GateThr parameter indicates the threshold level under which the AGC system is frozen, and does not
amplify the signal. While operating without the signal, the look-up table on the software screen visualizes the
AGC GATED status.
NB: the AGC stage wait a fixed time of 0.5 sec before intervening when the signal varies.
6.5 SETTING CHANNEL LINKAGE AND BAND COUPLING
The AGC circuit may work with left/right channel completely correlated, uncorrelated or partially correlated
(with percentage user-definable).
With L/R Linkage = 100 % the overall circuit gain is controlled by the greater of the left or right channel
signals
With L/R Linkage = 0 % the AGC control is completely splitted over the two channels (i.e an indipendent
AGC control is applied to each channel).
As general rule, a percentage = 70 % may help in compensate for slight difference in levels (up to around 3
dB) between input L and R channels.
In the same way, the AGC circuit may work with two bands completely correlated, uncorrelated or partially
correlated (with percentage user-definable).
With L/R Linkage = 100 % the overall circuit gain is controlled by the greater level on the top or bottom
bands
With L/R Linkage = 0 % the AGC control is completely splitted over the two bands (i.e an indipendent AGC
control is applied to each band, thus resulting on a kind of audio equalization).
As general rule, a percentage = 70 % (in association with a Crossing frequency and Cross slope between
bands well tuned on the actual audio material to be processed) may help in controlling ‘drum beats’ or low
frequency ‘punch’ music components whch may alter AGC operation on higher frequencies.