AW: VC envelopes

[Joachim Verghese]

> Now I see what you meant by replacing some transistors with a 3080. You
> still need switching of the various time CV inputs if you build an ADSR
> around this circuit. For a Minimmog- or SEM-like ADS, maybe
> the "sign" signal can take this part ...

That's right. Switching is inevitable for multi-segment envelopes,
I guess.

> Do you see any oscillation of the rectifier opamp when the slope reaches its
> steady state? It would be filtered out by the integrator,
> but I'd expect some internal oscillation with a loop around a sign /
> polarity circuit ...

I too feared oscillation, but none was detectable -- the circuit behaved
surprisingly well. I'll do some more experimentation with different
op-amp types, etc.

-joachim