Recasing of the Volca Modular to banana synth format.

Volca Modular is a poor man’s Buchla Music Easel, a modular synthesizer released by Korg. It’s a fun little synth with fiddly controls and simple but powerful sequencer. At some point I was annoyed by controls fiddliness enough that I decided to build a new better interface for it.

Bigger knobs and patch cables were obvious, but the challenging part was to keep the keyboard fully functional to be able to use it and the sequencer. I ended up with the idea to build a laser-etched plywood case with a precise slot for the keyboard. To my surprise, it worked right from the first try. I also added attenuators to oscillator CV ins (I missed it so much) and dropped a few extras like clock dividers, euclidean sequencers, and R2R DAC.


The process is straightforward but tedious:

  • screw new potentiometers and banana patch points to the panel
  • desolder all potentiometers and patchpoints from synth PCB, wire new ones
  • connect all ground and power planes

pcb_wiring

The front panel itself was also laser cut from plywood with laser engravings and then spray-painted. Engravings should be deep enough to be visible under paint coating.

Raw panel with an original volca case: pcb_wiring

Here is a final result with Pocket Operator for size comparison: pcb_wiring


This project was never fully finished, I didn't have time for a back panel with 3.5 jacks, audio cable was just sticking from the case, and the accu charging circuit was not integrated. Nevertheless, it was so much fun to play with!

In the end before moving to another city, I purchased a Make Noise 0-coast and donated my bananified Volca to the local hackspace. I’m sure she is in kind hands now.


Here is my last session with it (one go, no external effects):

Volca Modular is an engineering marvel, the PCB is so dense and good-looking, it’s portable and packs a lot of features, its reverb with CV control brings dynamics to the sound. The biggest weakness is triangle-only VCOs (it makes sound palette extremely limited), if at least one oscillator had a variable waveform, I’d never give it away.