SM Pro Audio OC8E: 8 channel optical Compressor User Manual

Page 7

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Installation - Front Panel Controls

Analog outputs
8 x ¼” TS analog output connectors are provided for each of the eight (8) compressor channels.
Individual output levels can be controlled via the associated channels rotary output gain control
encoder on the front panel.


4.1 Independent (8x) comp on/off bypass switches
The COMP switch toggles the channel bypass functions for each compressor module on or off.

* This is very handy for comparing compressed audio with your original non-compressed audio pro-
gram material.

4.2 Independent (8x) peak led indicators
Each channel features a peak light LED indicator. This momentarily indicates when the input sig-
nal strength has reached optimum input level.

* A continuously illuminated peak LED indicates you have surpassed optimum input level and dis-
tortion of the respective channels audio signal will occur. It’s time to adjust your input gain structure!

4.3 Independent (8x) rotary compression threshold encoders & tri-state led indicator
Each compressor modules COMPRESS encoder acts as a threshold adjustment. When input level
is below the threshold the signal is unaffected. When input level exceeds the threshold attenuation
of the output signal occurs.

A tri-state LED is available which indicates the following:

Green – Compressor module active,
Yellow/Orange – mild compression, input signal has exceeded the threshold level
Red – heavy compression, signal level has exceeded the threshold setting considerably

4.4 Independent (8x) rotary attack encoders
The rotary attack controls allow for adjustment in milliseconds the time it takes each compressor
module to respond to the corresponding input signals before gain reduction occurs. Short attack
times quickly bring down the level of the loud, fast transients in the audio signal; long attack times
let more sound through before the compressor engages, resulting in a punchier sound.

4.5 Independent (8x) rotary release encoders
The release controls set the time in seconds it takes for each compressor modules gain to return to the
point of no gain reduction in the absence of audio program material. Short release times create a more
exaggerated effect ("breathing"), whereas long release times have a more gradual, natural sound.

4.6 Independent (8x) rotary output encoders
The rotary output controls set the output level of each compressor module. Often after reducing the sig-
nals dynamic range with processing such as compression, you require a process to ‘make-up’ the lost

OC8E front panel