The DoepferA-135-5V Polyphonic Mixer is a specialized audio mixer designed specifically for polyphonic Eurorack patches. It features three rows (A, B, C) with four inputs each, tailored to handle up to three independent polyphonic voices. Each row includes a master level control with CV input with attenuator and a mute switch, offering dynamic control over complex patches. Row B includes a clever feature: If no input is connected, it automatically receives a square wave sub-octave generated by a frequency divider from the signal in row A. Row C functions identically to Row A but without sub-octave generation. The mixer provides four grouped outputs (each combining three signals), as well as a globalmix output that sums all twelve inputs. Ideal for setups with modules like the Quad Oscillator A-111-4, the A-135-5V can be directly pre-wired to it on the rear panel, significantly reducing cable clutter and streamlining patching. Beyond polyphonic use, the module also works as a voltage-controlled mixer for three mono signals with independent level control.