Saturday, 29 November 2014

A mini mixer for my lovely Volcas

I heart the Korg Volca range! If you don't know them already then, chances are you never will, however - they are a set of self-contained, affordable and  (mostly) analog synth/sequencer modules. There is a drum machine, 303-ish bassline synth, and a versatile 3-voice synth (they tease us with a currently unavailable sampler unit too). I love 'em .... but this isn't a review of them so Google as required..!

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?)


  1. Love the project! Where did you source the two layer laminate? That is an awesome way to do graphics, so simple!

  2. Thanks - I got the laminate from ebay seller buzzastral_2005.

  3. Hi...for make 6ch mini passive mixer are necessari change resistor value??

  4. Hi...for make 6ch mini passive mixer are necessari change resistor value??

    1. Hi - no I think the same values should be ok

  5. This is really awesome and exactly what I'm looking for to mix a Volca Sample, 3 Teenage Engineering POs and a LittleBits Synth kit. Thanks for publishing. BTW is there a reason this isn't on Tindie? Reckon you might get some buyers there, well 1 at least! :)

  6. Thanks! I have been considering making a little mixer like this for sale on Tindie – it is in the to-do list! Cheers/Jason

  7. Yes please! I'll buy one on Tindie for sure…

  8. One thing I've noticed on this circuit is that the output is quite low, any chance of adding a little headphone amp? :)