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.

Application examples:

• Crossfading of VCO waveforms (e.g. saw - rectangle - triangle)
• Crossfading of VCF outputs of multimode filters (e.g. lowpass - notch - highpass - bandpass)
• Crossfading of control voltage signals (e.g. envelope - LFO - random)