VC ADSR (was Pulse VCO Help)

[tomg]

> Anyway, I had a lot of fun figuring this one out and I am hoping someone
> will have suggestions, improvements, can point out areas of bad design,
> etc.  :-)
> 
> 
> Thanks,
> 
> Chris MacDonald


Actually, it inspired me so much I started messing around with it and before
long I had completely butchered your design...I though you might like to
look it over. The 4052 is really very clever Chris. Thank you for your effort.
Maybe you can find something here to help you with your idea.

btw this works really well!

Changes to Chris's design...

I used a transistor/cap to trigger the 555 - removed the opamp trigger.
I added a pnp  transistor to reset the 555 when the gate is removed.
I used a 3080/fet as a sample & hold - removed the 4066
I used a pnp exp-converter instead of the pulse vco
I added a opamp mixer to the sustain cv in 
I added a opamp comparator in the threshold loop
I added a opamp inverter for inverted out


http://www.mindspring.com/~vco/cbook/pics/vcadsr1.gif

-tg