Anyway, if you have Volcas you'll need some kind of mixer to combine their audio output for your listening pleasure, Even if you do have one (and I do own a Mackie mini mixer) the spontaneous mini-scratchpad style of the Volca's really needs something simple and lightweight that does not take a lot of setting up, so I decided to make my own passive mini mixer that I could keep set up with my Volcas. I keep my Volcas set up on a guitar pedalboard case so I wanted something I can keep, ready to roll, in there too.
A simple passive mixer would do trick (i.e. just a bunch of sockets and resistors with no power needed) and a Hammond diecast aluminium stompbox enclosure would fit nicely in my setup.
I used stereo sockets, pots and wiring - although I think the Volcas are all mono, so maybe I overdid it there, still - it keeps options open. My design has 4 stereo input channels which are combined into a single stereo output. The passive design works pretty well with the Volcas (the outputs are for headphones so they are pretty hot, an active mixer would be wasting time I think)
I jazzed up the enclosure using a piece of yellow/black 2-layer acrylic laminate which I laser-etched with a lo-fi pic of a good old C-60 (mix tape / mixer, geddit?)
