Module A-138f contains two identical crossfaders with three inputs and one output each. Three different signals are connected to the inputs A, B and C. In the ccw position of the corresponding control only signal A appears at the output. Between ccw and center position a mix of the signals A and B appears at the output. In the center position only signal B appears at the output. Between center and cw position a mix of signals B and C appears at the output. In the cw position only signal C appears at the output.
The module is DC coupled and can be used for both audio and control voltage processing.