VC envelopes

[Christian Hofmann]

On Thu, 4 Jun 1998 16:05:00 +0300 (EET DST)
Joachim Verghese <jocke at netcontrol.fi> wrote:

> Yes, I noticed that. Those VCAs are probably a lot better than
> the 3080. And the env "logic" chip probably includes expo converters
> for the time parameter inputs too.

I don't know too much of them, but isn't any VCA better than the 3080?


> Juergen wrote:
> > Special Award for "most different" VCADSR solution goes to Roland's
> > JP-4. Variable resistors are emulated by analogue switches and smoothing
> > capacitors, and each switch is controlled by a little expo VCO.

That reminds me of switched capacitors. Wouldn't that be usable for ADSRs?
Having a quasi-variable capacitor, with a moderately high operating
frequency (compared to audio). Time constants would be controlled from a
reference voltage by PWMing a fixed saw osc. Or is this just what is done
in the JP-4?

cu
Christian