One of my old friend working as a sound engineer once told me he was sick of pristine clean compressors. So I came with the idea of doing a compressor that can either be dirty (or say, with a fair amount of temper) or clean.
If you think of a compressor as an amp with automatic gain adjustment, it's audio qualities are defined by :
– The amp part : in this case it's a JFET amp with a fair amount of gain, which means that with high input values, you can get a bit of tube-like distortion. But with low values, the sound is clean and hot. I suggest you start by setting the comp at zero and play with the gain/volume knobs and the bad switch, to really hear were the pedal can go with your instrument... I know that with a guitar you could get nice crunch tones. With a bass it's a bit different...
– The automatic gain adjustment part : it is an optical compressor, meaning I used a photoresistance named “vactrol” to control the gain automatically. The vactrol is known to be a bit slow, especially for the release. So I tried to compensate by designing the fastest automatic control I could, achieving around 1ms attack time on the “fast” setting...
Compressors users should know that this one has a ration of about 6.