The A-135-5V Polyphonic Mixer from Doepfer is an audio mixer that has been specially developed for polyphonic patches. The mixer has three rows with four inputs each. Each row (A/B/C) has a master level control with CV input and attenuator as well as a mute switch. If an input in row B is not connected, the signal of the frequency divider is automatically applied, which generates a square wave one octave below the signal applied in row A. Row C behaves like row A, but without the following sub-octave. The audio output is divided into four groups, each with three signals and the mix output, which outputs all twelve signals together. The module is designed for three polyphonic patches and can be used as a VC mixer for three signals with individual level control. For polyphonic patches, the Quad Oscillator A-111-4 is a good partner as it can be pre-wired to the A-135-5V at the rear, which saves a lot of cables.