TL Audio C-1 - Manual (Page 12)

Ratio.
The ratio may be varied from 1:1.5 (very gentle compression) to 1:30 (near limiting).
The compressor normally operates with a “soft-knee”, i.e. the compression is
gradually introduced as the signal passes the threshold, in which case the ratio refers
to the compression eventually obtained.
Gain Make-Up.
Up to 20dB of gain make-up may be applied, to retain the subjective loudness of the
signal.
Stereo Operation.
In normal 2 channel operation, the controls operate independently for each channel.
The compressor may also be set for full stereo operation, where the Threshold, Attack,
Release and Ratio controls for channel A control both channels. The input gain and
gain make-up controls remain separate to allow relative input/output gain balance
adjustment.
In stereo mode, the control voltages are also linked, ensuring that the same amount of
gain reduction is applied to both channels (even if one signal is below the threshold).
This ensures that the stereo image is preserved.
VU Meters.
The compressor is equipped with twin, illuminated VU meters. These meters normally
monitor the audio output from the unit, and are calibrated for 0VU = +4dBu. The
reference point may be internally adjusted by your dealer if required.
The meters may be switched to indicate the amount of compression occurring. If the
signal is below the threshold, the meters will indicate 0dB: i.e. no gain reduction. As
the signal passes through the threshold, the meter will indicate the gain reduction
occurring at the compressor stage. Note that the gain reduction indicated is a measure
of the degree of compression, and does include any gain make-up applied.