Nonlinearcircuits – Kareishuu VCO
This VCO was mainly designed as an upgrade for the dual OTA VCO. It is a traditional triangle core VCO with a built in VCA for the FM control section. The design draws on sections of the Electronotes EN1, EN2 and EN3 VCOs along with some NLC injected in there for good measure.
It has much better tracking, a sine output and attenuators for all inputs. The self modulation control via the FM VCA enables voltage controlled waveshaping, the sine and tri waves can morph between their original shape to a pulse.
The pot spacing is quite tight, so I suggest using T18 knurled shaft pots along with the micro knobs. Other than the 1k tempco, no rare parts and a fairly easy build.