Owner`s manual
page 6
• Pin 9 is connected to the tip of the 1/4” TRS connector labeled “OMNIPORT” on the Radial
Workhorse or “OPT IN” on the Purple Sweet Ten Rack for stereo linking or side chain signal input.
• Pin 11 is connected to send an unbalanced audio output to the Radial Workhorse “BUSS FEED”.
If you are using either of these racks, please refer to their documentation for operating with these
connections. Also, please refer to the ‘Card Edge Connector’ and ‘Jumper and DIP switch locations’
diagrams on pages 9-10 of this manual.
Operation
The compressor circuit is based on an optical attenuator - the purest, high delity gain control
mechanism available. It provides gentle to fairly heavy compression, while remaining neutral and
transparent. This compressor is not designed for “brick wall” limiting.
Similar to an eq, dynamic range compression is a subjective tool – there is no wrong way to use it.
However, using a compressor in a way that produces the best results can be tricky, and the more you
know, the better it will work. If you are unsure about how a compressor works, we highly recommend
some preliminary reading:
http://en.wikipedia.org/wiki/Dynamic_range_compression
It will pay greatly to understand the mechanism of dynamic range compression BEFORE you begin to
record keeper tracks with the compressor on.
SETTING THE INPUT TRIM
This switch selects between three input levels: -10, 0, and +10dB. Select the setting which best suits
the level of the incoming line signal and how much compression you require. This setting is interactive
with the threshold control, as a higher input level setting will result in a relatively higher threshold
setting to achieve the same amount of gain reduction. This control eectively sets how hard you drive
the compressor circuit.
SETTING THE THRESHOLD
The threshold is the level at which the compressor begins to attenuate the incoming signal. A high
threshold setting (counterclockwise) will result in only the dynamically highest passages of the signal
being attenuated, while everything below that threshold is unaected by the circuit. Conversely, a
lower threshold means more of the signal at the input of the circuit will be attenuated resulting in
more compression.
Begin with the knob fully counterclockwise and the compressor switched ON, then slowly begin
turning clockwise until you begin to compress the signal. You will hear the signal compress, and you
will begin to see the GR meter light up. The lower the threshold setting, the more the incoming signal
will be attenuated and the more lights will light up on the GR meter.
SETTING THE ATTACK RATE
The rate at which you want the compressor to start the attenuation of the signal (attack phase)
depends on the character, or envelope, of the signal entering the compressor. If the signal has sharp or
fast attack (percussive sounds, snare drum) that you wish to attenuate, select a fast attack rate to sense
the initial impulse of the signal and attenuate it in time. If you want the compressor to react slower and