Carl Martin CompressorLimiter has been specially developed to incorporate the same features and sonic clarity found in high quality professional studio compressors. To achieve this we incorporated a variable threshold, -variable compression ratio, -variable attack and release controls and of course, a gain level. Threshold Working anti clockwise, determines how much of the signal will be compressed. This is also dependent on how much signal is fed from the instrument. Comp Working clockwise, determines how much compression is applied to the signal allowed by the threshold setting. Resp Working clockwise, determines the attackrelease times, going from slow to fast. In general, if you want to hear the compressor working with a crisp attack you should use slow times. If you require just a silent limiting you should use fast times. Gain Working clockwise, sets the overall gain. Busy Indicates the amount of compression being applied, even in bypass mode. The brighter it gets, the more compression is being applied.