optocouplers (was:RE: Re[4] ...)

[Haible_Juergen#Tel2743]

>     So first I
>     wanted to see if there was anything I already had lying around so some 

>     gut instinct led me to the parts drawers here at work (shhhhhh...) and 

>     into the optocouplers. I picked one at random (4N37) and tried it out. 

>     It worked!

Gene, you're truely a Genius !
Would be even better than with OTAs (my preferred method so far,
but only tried with ADR, not full ADSR) !

One question, though:

With OTAs you always have to apply a feedback loop to get
"RC-type" exponential slopes.
With Photocouplers (LDR ...) you have a true variable resistor,
so exponential slopes.
But the Optocouplers ... wouldn't they be quite *linear* (i.e. nearly
constant current charge/discharge) ?

I hope this will not ruin the whole thing ... If you have to add feedback
as well, the major advantages would be gone (ease of use and
potential-free action).

Please tell us when you have first results !

JH.