User Guide

Figure 3.4: UltraChannel O-Pressor Section
3.4.3 Threshold
The threshold control sets the knee level of the O-Pressor’s compression circuit. This control ranges from
-50 dB to 0 dB.
3.4.4 Ratio
This sets the O-Pressor’s ratio from 1:1 (off) to 100:1 compression.
3.4.5 Attack Time
This control allows you to adjust how quickly the O-Pressor reacts to signals above the selected thresh-
old. Values range from 100 us to 50 ms. The attack value displays numerically beneath the Attack
control.
3.4.6 Release Time
The Release control determines how fast the O-Pressor responds to decreasing signal levels. Release values
range from 1 ms to 500 ms. The release value displays numerically beneath the Release control. At very
fast attack and release times the O-Pressor works more like a distortion circuit than a compressor.
3.4.7 Make-Up Gain
The Make-Up Gain control for the O-Pressor module allows you to apply make-up gain to the O-Pressor’s
output. The O-Pressor supports gain values from -30 dB to +30 db. The gain value displays numerically
beneath the Gain control. The gains in these sections also allow you to overdrive any elements that come
after them
3.4.8 Bass Cut
The Bass Cut knobs allows you to set the corner frequency of a high pass filter in the O-Pressor’s side
chain. The O-Pressor’s level detection circuit can be particularly sensitive to low frequencies, so this can
be very helpful when applying compression to kick drums or bass heavy instruments.
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