Fuzzpilz Oppressor

Oppressor is a compressor/gate/thingy.

Parameter	Explanation
Track Mode	Whether the signal is to be passed through all the tracks at once (parallel) or one after the other (series).
Level L/R	Where to get the level for the left/right channel: the normal input or an aux channel.
Pregain	Preamp gain.
Output	Oppressor can output either the processed signal or its level; the latter is useful in combination with a ringmod.
Mode	Compress/limit - the signal is attenuated if its level is above the threshold. Gate - the signal is attenuated if its level is below the threshold. Unlevel - The signal's level is set to 0 dB if it's above the threshold.
Level	Oppressor can react logarithmically (usually better) or linearly. The difference should be quite clear when looking at the graph.
Threshold	Threshold level.
Ratio	Compression/gating ratio. Has no effect in unlevel mode.
Attack	How quickly Oppressor reacts to increases in the input level.
Decay	How quickly Oppressor reacts to decreases in the input level.
Knee	Higher values generally result in a smoother response.
Knee type	Oppressor knows various ways of applying the knee value.
Postgain	Postamp gain.

For easier fun, Oppressor has a builtin magic level response graph thingy. Right click on it in the machine view and click "Show" to see it.