Buzz Audio soc-20 mid side optical compressor - Manual (Page 6)

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S/C INSERT
The SOC-20 is fitted with a side chain insert point. This allows you to place
another device between the audio LINE input and the SOC side chain circuits. (If
you are unfamiliar with the term “side chain” it is the circuit in a compressor
which takes the audio signal and generates a suitable signal to control the
gain reduction element, whatever that may be).
A device can be connect to the S/C INSERT rear panel connectors and engaged
by placing the S/C INSERT switch down (IN). If no device is connected, the
compressor will stop working when switched to IN.
You can also monitor the S/C INSERT RETURN signal by placing the S/C INSERT
switch to the up (MON) position. Note that if nothing is connected to the insert
return input, the monitor function will not work. To allow monitoring of the side
chain in MS mode, use a patch cable to connect S/C Insert Send to the S/C
Insert Return.
Typical uses for the side chain insert point are inserting an equalizer so
complex frequency dependant compression can be accomplished, for example,
de-essing. Using the sound of an instrument to compress another instrument
(often called keying) using the insert return as the key input.
PK LED
This red led will light when the internal operating level has reached +22dB
peak level indicating a possible clipping situation. It monitors the input and
output circuits of the SOC-20.
LDR LED
This led is driven by the SOC side chain control signal and is provided to give
an indication of attack and release settings and how they are applied to the
audio. It can be mesmerising to watch – you have been warned!
SEPARATE-LINK A/B
In SEPARATE mode, the SOC-20
operates as two completely
individual mono channels. When
switched to LINK A/B, the
compressor side chains are
linked to provide stereo tracking.
This mode is used to prevent the
stereo “image” shifting if a loud
sound appears only in one
channel of a stereo mix. For
example, if this mode is not
selected, a loud floor tom panned hard left in a mix may cause the output
stereo image to move towards the right as more gain reduction occurs in the
left channel than the right (when used in Stereo Mode of course).