CA3046 exponential converter

[Michael B. Irwin]

The Moog Prodigy, Multimoog and Micromoog all use the "CA3046
Thermostat" circuit with no temperature compensating resistor (similar
to the AN-299 VCO). The rest of the VCO uses inexpensive dual BIFET op
amps (TL072 or LF353) with an LM393 dual comparator and a JFET for
capacitor reset. I duplicated and modified the Prodigy VCO design and it
works well-however I have never built a "Q81" thermistor compensated VCO
to compare it with.