UAD Powered Plug-Ins Manual v5.2 - Just Music

Stereo, coupled
mono/stereo
Modes Table
This mode, like stereo couple left/right, causes the two compressors to be
linked together so that they always compress the same amount. But here, the
inputs to the two compressors are fed with the mono and stereo components
of the signal. This means that in general a transient which occurs in both channels
will cause a bit more compression than a transient which only appears on
left or right. The attack and release behavior is determined by the average of
the settings for the two channels.
The mode in which the compressors operate is determined by the combination
of the AGC switch and the Sidechain Link switch. The switch positions required
for each mode is shown in Table 8 below.
Table 8. Fairchild Operating Modes
AGC Switch Sidechain Link Operating Mode
Left - Right Unlinked Dual Left -Right (Dual Mono)
Lat - Vert Unlinked Lateral - Vertical (Dual mono - stereo)
Left - Right Linked Stereo, couple left - right
Lat - Vert Linked Stereo, couple mono - stereo
Gratuitous
Question
Is there any reason I would want to link the two sidechains together and still
have the settings for the two channels different?
Yes. Linking the sidechains simply prevents left-right image shifting. Threshold
and input gains can be set independently to cause the compressor to be more
sensitive to instruments which are panned to one side or the other. Output controls
can be set separately in order to correct an overall image shift at the output.
Controls
Power Switch
Metering
This switch determines whether the plug-in is active. When the Power switch
is in the Off position, plug-in processing is disabled and UAD DSP usage is reduced.
VU Meters
There are two calibrated VU meters, one for each channel. What the Meter
displays is determined by the Meter Switch.
UAD Powered Plug-Ins Manual - 126 - Chapter 13: Fairchild 670