This is my first Axoloti project!
Couldn't wait for the new Volca FM to come out so I made my own.
The Volca Keys has a modded MIDI out (simple soldering job) which is connected to the Axoloti running an FM synth patch based on the ones made by MartijnVerhallen (https://sebiik.github.io/community.axoloti.com.backup/t/frequency-modulation-patches-pack1/205) with some modifications (3-voice polyphony, flanger, LFO and LP filter), the beats are coming from the PO-12.
Good response for this and the Axo on reddit.
https://www.reddit.com/r/synthesizers/comments/43gd3x/diy_volca_fm_with_axoloti/
Cool! Thx for sharing to reddit! I don't have a reddit account myself so I can't answer any of the guys questions.
Here's a guide how to mod the Volca: http://blog.utopianlabs.com/2013/09/korg-volca-beats-midi-out/ Every knob except the resonance/peak and volume knobs output CC, sequencer outputs polyphonic MIDI note data, sync and parameter changes.
Here's the subpatch for a voice, just drag it into a fresh patch and set polyphony to 3.
volcaFM-voice.axp (6.6 KB)
This little ARM processor managing 3 voices with 6 fm-operators each? Awesome! Too bad it can't do proper fm-feedback (operator modulating its own frequency) with only one sample latency, because of the current design. Try generating white noise.
It's only 2 operators, but there is feedback and it's only about 26% DSP load (so some more operators should fit in easily). I don't know much about FM synthesis though and I'm still just making baby steps with the patcher.