[sdiy] new schematic posted

[Ingo Debus]

Am Freitag, 04.06.04 um 02:29 Uhr schrieb harrybissell:

>  Its called the MorphLag...   It is a lag circuit with separate
>
> attack and decay controls... and a shape control that varies the 
> response
> between linear and log.
>
> Its built and tested, enjoy.
>
> http://www.wiseguysynth.com/larry/schm.htm
>
>

Nice circuit. I must confess, it took me a while to find out why the 
output of AR3 is tapped off *after* the diodes and not directly from 
the opamp's output. This is to compensate for the diode voltage drop, 
right?
But doesn't this cause some interaction between the attack and the 
decay pot if the shape pot is not in one of its end positions? As I 
understand it, one one of the diodes conducts at a time. Say, the 
attack diode conducts and the attack pot is set to some high 
resistance. Isn't there some voltage fed into the integrator via R9 and 
R10 and the decay pot? Unless the shape pot is in an end position, in 
this case this path would be shorted to ground or virtual ground. But 
if the shape pot is in center position, R9 and the two halves of this 
pot form a voltage divider. So the decay pot would have an influence on 
attack too.

Another question, as I see it, in linear mode (wiper of shape pot at 
ground) AR3 is overdriven (no local feedback). Can't it latch up?

Ingo