From MMM Wiki
4-input mixer capable of handling audio or CV signals.
Simultaneously available inverted and non-inverted outputs.
Independent attenuation for each channel
"Punch-in" toggle switch on each channel to allow for "pre-setting" an audio or CV source on the channel, then "punching" it into the mix for realtime dynamic CV or audio control. Or simply, a channel on-off switch.
This module is currently available. $190.00
PCB board dimensions:
3.125" (3-1/8") 79.38mm X 2.625" (2-5/8") 66.68mm
Mounting holes: 0.125" (1/8") 3.18mm (for 4-40 screw) 4 holes, one in each corner
Mounting hole spacing; Length: C-C= 2.925" 74.3mm, Width: C-C= 2.425" 61.6mm