What is a compressor and what does it do?
Basically, a compressor is a form of AGC (Automatic Gain Control) circuit. As a signal goes through it, the compressor adjusts the rate of level change of the signal. This change is measured in a ratio, from as little as 2:1, which is a very minor change, to as much as 100 to one, which will act as a “brick wall” limiter that won’t allow any increase in level. For most bassists, a ratio of 2:1 to 4:1 is the sweet spot that will level the signal without being objectionable.
