AW: Weird Envelopes??? [was RE: CS-80]

[Haible Juergen]

	>And perhaps the most spectacular EG-type design
	>is/was the Buchla Quad Function Generator. This device used two
pairs of
	>EG-like circuits which could be fired in a quadrature
relationship: A
	>fires, A reaches sustain then B fires, B reaches sustain then A
drops, A
	>goes to zero then B drops. You could hook up the pairs in
quadrature
	>relationships, as well, and set up cycling ASR-type envelopes
off of a
	>single input trigger, and even take this way up into AF range
if desired.

Sounds interesting !
Reminds me of the EMS "Trapezoid", where the "On" and "Off" times
are (of course) produced by capacitor charge / discharge slopes.
So in this case you'd just have to bring this internal voltage out, do
some
rescaling etc.
But it's hard to imagine this for ASR-type envelopes - at least for
their
common implementation where the sustain phase is just an asymptotic
tail of the (exponential) decay phase ...
Of course one could trigger the attack of a second ADS when the peak
voltage of the first one is reached, but I doubt that this is what you
tried
to describe.
More information about the Buchla Q F G would be great - schematics even
??

JH.