[sdiy] VCA response - continously variable between linearand exponential

Tom Wiltshire tom at electricdruid.net
Sun Mar 3 11:53:40 CET 2013

On 3 Mar 2013, at 04:49, rsdio at sounds.wa.com wrote:

> In other words, I again ask: Why would you want anything besides linear or pure exponential? Something in between doesn't seem terribly useful. (not that a synth designer shouldn't create additional parameters for variation)
> Brian

We're talking about VCAs, so the reason is to do with amplitude envelopes. Although we might need a pure exponential response to get a smooth ramp-sounding envelope, that isn't remotely realistic. What sound has an envelope that rises smoothly and consistently?!  In reality, envelope shapes are pretty variable (some even have little wobbles in them). So whilst we might want a linear VCA to go with our expo envelope, we might want an expo VCA to go with our liner envelope, and when the envelopes get more interesting than that, the VCA response could get more interesting too. That would all provide realistic variety in the volume curves we're able to generate.

In some ways, though, I consider a linear VCA to be the ideal, and reckon all the messing around with the shapes should be done by the envelope generators. So I sort-of agree that expo and linear pretty much cover it, and even expo's a bit superfluous. If you want a bendy curve, use a bendy curve generator.


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