[sdiy] 3080/13700 OTA question

[Brock Russell]

I built this back in '76, my first significant synth project, and 
from looking at the vca boards and my lack of notes of any errors, I 
think the circuit is correct as drawn. I used the pwm attack/decay 
driver circuits too. The circuit might be correct but the performance 
was poor, very noisy and lots of feed through. Hope you have better results.

Brock


At 10:03 AM 1/2/2009, Tim Ressel wrote:
> > Clearly an error on the drawing.  My guess would be that
> > the 10k and 2.2M resistors are swapped.  this would give you
> > envelope time up to a few seconds and 1.5 mA of Iabc.
> >
> > Ian
>
>Interesting! I dug up a copy of the June '76 Popular Electronics 
>article and it has the same values. Of course they both could be 
>incorrect. I will try swapping the 10K and 2.2M right away.
>
>--TimR
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