SMR4 v0.5 oscillation mod?

v0.6, v0.7

Removed middle spacers holes.
Self-oscillation in 2-poles mode.
Increased hole sizes for audio and DC connectors.
Added pads for external CV sources on cutoff.

i haven’t seen that before. what will i have to change on the older SMR4 boards?

Yeah rosch, interesting question. Seems like we finally found a purpose for the 2nd switch of the mezzanine mod…

v0.5: what was fed back to the resonance path was the selected pole signal (ie, the same signal was sent to both the VCA and fed back to the filter)
v0.6, v0.7: what is fed back to the resonance path is always the 4th pole, which is 180° dephased with the original and thus allows self-oscillation.

Not sure how to do it easily…

I have an easy way - i need v0.7boards…