[sdiy] Korg Volca Bass service manual

[Andrey Salomatin]

Very interesting! Thank you for sharing!

Any ideas on what that input circuit for the VCO CV is and does? Looks like a summing amplifier and a filter, but it’s non-inverting? Is it doing some PWM conditioning magic?

Andrey
 
> On 26. Oct 2026, at 22:00, Sean Ellis via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
> https://cdn.hackaday.io/files/1698407266434560/korg_volca_bass_sm.pdf
> 
> Not sure if this has been shared but here's the manual, as usual some interesting circuits from Korg. Schmitt-trigger in the VCO and a very low parts count on the VCF, not a trimpot on board! Has anyone heard one of these? I'd be interested in how the filter sounds.  
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