Envelope gen operation

[Byron G. Jacquot]

> I have decided to make my ADSR dual-function. If a gate arrives then an ADSR
>cycle will be done. If a lone trigger occurs, then an AR cycle is done. Its
>almost like I have two gates: one for ADSR and one for AR. 

I've got an old EG design that's something like that.

It's really a coupled AD generator, with a parallel AR generator, bith
driven from the same gate.  The outputs are summed together to make the ADSR
shape, and the attack pot is a dual-ganged one.

With a little work, this module could be a lot more flexible, if I'd broken
out the individual AD/AR shapes, and had both attack times on their own
pots...then up to 2 trigger inputs as well...I might as well just build two
seperate modules!

Byron Jacquot