A 100% analog old-school compressor from the days where colouring was an important factor to the sound. The four controls (from left to right) are the Gain, which controls the ‘pre-glow’ of the optical circuit (the more you turn this up, the fatter the sound); Level, which controls the overall volume of the compressor; Compression, which controls how hard or soft the compression is, and the Attack control which takes the signal from transparent to outright total squeeze.