The classic VCO

The VCO is based on a relaxation oscillator. The integration/relaxation circuit is build around discrete high quality components. Transistors/current sink with excellent log conformance, zero temperature dependence capacitors and very fast JFETs with superlow Gate capacity for fast switching. This delivers classic sounds over 6 octaves with 0 cents deviation (8 octaves within +-2cents). The shape of the sinewave output can be readjusted with trimmers in shape and symmetry, giving even more possibilities in timbre.
A selected passive temperature compensation circuit takes care of long term frequency stability in a reliable manner, 4h drift measurement = 0 cent deviation.
All I/O signals are accessible on an pinheader for prepatching when built in.

Tunable parameters:
TUNE COARSE
TUNE FINE
PULSEWIDTH

Inputs:
FM EXP
FM LIN
PW CV
SYNC

Outputs:
SAW
TRI
SQR
SINE

http://seismic.industries/vco