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Compressor parameters, Sidechain mainchain in- put out- put – Edelweiss GAMBIT DS1-MK3 User Manual

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OPERATING INSTRUCTIONS FOR GAMBIT DE-ESSER/COMPRESSOR DS1-MK3

OPERATION

Weiss Engineering Ltd., Florastr. 42, CH-8610 Uster

Page 9

+41 44 940 20 06 +41 44 940 22 14 http://www.weiss.ch

[email protected]

Compressor Parameters

Following is a detailed description of all parameters that can be adjusted in the compressor stage. Guide-
lines are given for settings (see also the factory presets), but optimal settings are usually programme
dependent, so experimenting and listening is inevitable for satisfying results.

Graphic 5 shows schematic and parameters of the DS1-MK3 compressor stage:

Delay

A typical compressor/limiter circuit measures
the audio signal and then generates the gain
reduction control signal. At the time the control
signal changes the gain, the programme materi-
al is already there, so the gain change occurs
too late. The result is overshoot and possible
subsequent distortion.

The DS1-MK3 uses a different method to gener-
ate the gain control signal: The audio passing
through the mainchain is delayed by a fixed
amount of time, determined by the „overall de-
lay“. By branching the signal out of the delay
line, the sidechain „sees“ the signal before it
reaches the output, thus allowing look-ahead
compared to the mainchain. The resulting cor-
rected output signal has no overshoots, no lead-
ing edge distortion or other side effects due to
timing lags in the sidechain.

The preview (the time the signal reaches the
sidechain ahead of the multiplier) cannot, of
course, exceed the overall delay.

The overall delay is the sum of the maximum
overall delay („Delay“ box in Graphic 5) and the
delay required for other signal processing (line-
ar-phase filtering for up- and downsamplers).
Any snapshot value of the preview delay which
exceeds this maximum, is clipped to the maxi-
mum, because the overall delay is not stored in
the snapshots and therefore the preview delay in
any snapshot can exceed the currently selected
overall delay.

Setting overall delay: The overall delay is

adjusted by pressing the „menu“ key (

) then

selecting the „system“ and then the „overall
delay“ option. Use the gain / data controller

(

) to change the delay value. Maximum con-

sequential preview time and delay in frames is
also displayed. Please note that during delay

Delay

overall
delay

preview

Envelope
Detection

attack

release
delay

release
fast

average

RMS

release
slow

Non-Linear
Transfer Curve

soft-knee

threshold

ratio

gain
makeup

x

Sidechain

Mainchain

In-
put

Out-
put

audio signal

gain control
signal

Graphic 5: Compressor schematic