[sdiy] 3310

[Scott Bernardi]

Try http://members.home.net/sbernardi/elec/og2/og2_cem3310_adsr.html
I don't have VC input jacks for each of the pots, but all you would have to do is
turn the U2 opamps into summing amps instead of buffers.
For example, on U2:D, put a 100K in the feedback loop (between pins 13 & 14), then
a 100K from the - input (pin 13) to your Attack control voltage jack. Ground pin
12 (+ input), and take the wiper of RV2 through a 300K to the - input (pin 13).
The top of the pot should be connected to V+, and the bottom to ground. Then
change R6 to 18K.   Repeat for U2:A and U2:B.
This will give a control voltage that is the sum of the pot position and the VC
input jack.
The Sustain input is a bit different. Here you need a summer without the
inversion. The easiest easy would be to add another opamp (say a TL072), configure
one as a summing amplifier that sums the pot voltage and a Sustain control
voltage, then runs it into a -1 inverter.


Gur Milstein wrote:

> Hi Guy's
> Any body know where I can find  schematic of a VC ADSR using the cem3310 chip.
>
> thanx
> Gur Milstein

--
Scott Bernardi
sbernardi at home.net