VC ADSR

[jorgen.bergfors at idg.se]

>After a lot of struggling I have come up with a circuit for a voltage
>controlled linear ADSR.  I have breadboarded it only, no module yet. The >voltage control is done with OTAs (LM13700), the rest is based
>loosely around my previous ADSR.  I borrowed a bit from Juergen Haible's
>AD circuit (thanks!).  It is not a perfect circuit by any means, I had
>trouble getting the sustain level to go entirely to 0V (minimum seems to
>be 5 to 10% of max envelope magnitude) and the transition from the decay
>to the sustain is a bit rounded, but overall it works okay.  I would
>really appreciate any comments or suggestions on improving this circuit.

>http://www.evenfall.com/diy/vcadsr.gif

>I plan to use this with an expo converted LM13700 VCA.

>-Chris MacDonald

Why reinvent the wheel? Why not build Juergen Haible's new VCHADSR instead? I have made a version with my punch feature added, and designed a board for it. Works like a charm!
Right now I'm working on a quad module, utilizing this board. 

/Jorgen