This is a strictly utilitarian module. The holes are extra uneven on this one because I reused an old LFO module when putting together this module, and it has been updated at least twice since then.
This is a confusing module as the mixer portion is just the top chunk of gray jacks plus the rotary controls and jacks below the controls. The collection of 10 jacks in the middle have nothing to do with the mixer, but are just simple converters for 1/4" cables, and 1 BNC jack for use with oscilloscopes, function generators, or other test equipment that use the BNC as the standard connector. Two of the 1/4" jacks normally connect the returns from my computer, and a third connects my Peterson virtual strobe tuner for tuning up the VCOs. The forth is often unoccupied, but useful for adding external sources like keyboards, radios, guitars, etc.
There are two separate and identical mixers available. Each has 4 inputs that sum together and the summed output is mult'd across three jacks. The lowest blue jack is an unattenuated output, meant to patch into the master mixer module (which has a fader and pan control for each input). The other jacks can be attenuated, and are meant to be effects/aux sends. The upper blue output is fed from the attenuator above it. This is meant to feed the modular effects like the Dual Delay and the Boss Phaser (or it could feed another VCF, the Ring Mod, or whatever). The 1/4" output is fed from the other attenuator, and this is meant to be sent to the outside world for recording or processing. These are normally sent out to my computer.