Envelopes (was: Need help!)

[Haible Juergen]

	>VCAs: can be linear or exponential. Most are linear, because
the envelope generators are >outputting exponential
	>waveshapes. The ear has a more exponential response to relative
volume (the "Fletcher->Munson" curve). Linear
	>envelopes are easier to generate in software (just a counter),
so an exponential response >VCA makes sense. In
	>reality neither is "correct", its that a exponential EG feeding
a linear VCA is easy to do >from a hardware standpoint,
	>and the 'natural-ness" of the result seems OK.

In all this speaking of the ear's response, and the resulting
combinations
[exponential envelope + linear VCA]   or  [linear envelope + exponential
VCA],
one thing is generally overlooked: These two combinations may be
interchangeable for the release part of the envelope, but not at all for
the
attack part. Your ordinary exponential shaped attack follows an expo
function,
but it has the "wrong" orientation, and is more or less truncated.
Nevertheless,
it "feels" quite right, and certainly better that the other option, for
most
applications.

JH.