3 blocks of 2-channel attenuverting mixers, using dual concentric pots. Each channel can be switched to mix with the subsequent channel, allowing for 2-2-2, 4-2, 6 mix configurations.

With nothing plugged into an input, an offset is normalled to that channel. The inner knobs control the A inputs, while the outer knobs control the B inputs.

DC coupled, so it can be used for audio, CV, or both at the same time.