This 12HP Eurorack module provides four separate VCAs, for which each has an input, CV and output jack.The VCAs are able to amplify the inputted signal using either the knob, or the inputted signal to define the amount of amplification.Whenever some CV is plugged in, the knob can be used to offset the CV.Each of the VCAs can also be used for distortion.Whenever the knob passes the midway point, or enough CV is inputted, the VCA has reached its maximum amplification level, when surpassing this amount, the signal starts to clip/ distort.This may add a nice rough edge to your sounds.