[sdiy] Figureing out Buchla timbre waveshaper

[Titus Anderson]

> in----R1--+------------------+---R3---- out
>           |                  |
>           |   \              |
>           |   |\             |
>           +---|-\            |
>               |  \           |
>               |   \          |
>               |    |---R2----+
>               |   /
>               |  /
>  gnd-resistor-|+/
>               |/
>               /

I'm pretty new to this, but it seems to me that as long as the op-amp hasn't
saturated to -6 or +6V, the output current is 0.  When it does saturate,
however, the input current isn't completely cancelled and so some of it
makes it to the output.  With resistor R3 (which I added to the diagram),
you'll end up with a small peak 180 degrees out of phase of the input.
So, for a triangle input, you might end up with something like this at the
output:

input:
\      /\      /\      /
 \    /  \    /  \    /
  \  /    \  /    \  /
   \/      \/      \/

output:
 __/\__  __/\__  __/\__
/      \/      \/      \

Can anyone confirm this?
-- 
Titus Anderson