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2. FUNCTIONS
From left to right, the first stage of the Variable Gm is the Remote cut-off preamp.
The available controls are:
a) INPUT
It is a continuously variable pad which levels the incoming audio signal from the
Input XLR connector located at the back panel. In conjunction with the OUTPUT
control, it imparts the colour of the compression. The more signal you feed to the
remote cut-off stage (input stage), the more coloured and ‘saturated’ the
processed audio will be. It’s an attenuator from –inf. To 0 dB, and is active only in
LIMIT mode.
OUTPUT
It is 9 dB variable attenuator (pad), it will serve you to trim the output signal if you
need gain on the INPUT selector. It works in conjunction with it to determine the
compression action. 0dB point: input at -18, output at -9 (full CCW).
METER FUNCTION SWITCH
Toggles between IN, GR, OUT. In the first position (In), the VU meter indicates the
average (very similar to RMS) level of the signal present at the Input XLR connector
for that channel. A 0VU indication lets you know that a +8 dBu (1.947Vrms) signal
is present. Consequently, the +4dBu indication is found at the 50% on the percentage
scale.
GR: Indicates the amount of gain reduction. The movement deals with the current
variation of the remote cut-off tubes during the peak reduction action. The needle
stands at the 0 with no compression. Even if the current variation has a relationship
with the dB’s of compression, the scale is not read in dB directly. You will have to
learn the correct dB indication by ear. Usually when the needle is at -1, you’re having
about -2.5/-3dB of Peak Reduction.
OUT : Applies the same spec’s as in the IN position, but the meter is actually
monitoring the signal present at the Output XLR connector.
ATTACK
This controls the Attack time, the time when the compression action starts. The span
is from 25 ms, fastest, in full cw position, and 100 ms, slowest, full ccw position. The
time indication refers to the first time constant, i.e. when the reduction reaches 63%
of it’s final value.
