Modular Synth Panels

On 3/1/08, Grant Richter put forth:
>  > Also, I took a look at the schematic.  According to the above
>  > website, this module uses 0 - 10V, and I wanted to see how easily it
>  > could be adapted to the -5V/+5V that MOTM generally uses.  It looks
>  > like all the op-amp outputs are wired as comparators (ie. with
>  > positive feedback).  If that is a mistake, perhaps it should be
>  > corrected.
>
>Orcad library op-amp symbols have the minus input on the bottom, and
>the positive input  on the top, don't ask me why. Don't assume
>op-amp symbols are always drawn with the negative input on top, it
>has become conventional recently, but different schematic software
>may not follow that convention, and there are no regulatory bodies.

These are drawn according to that convention, with the negative input
on top.  It's labeled with a "-" and the number 2 (which is an
inverting input on a TL072).   The feedback goes from the output
(labeled 1, which is an output pin on a TL072), along the bottom, to
a an input labeled with a "+" and the number 3 (which is a
non-inverting input on a TL072).   So I don't think I'm assuming
anything in suggesting that if it isn't meant to be a comparator,
then perhaps the schematic should be corrected.

http://diy.czmok.de/mod/gbuy/wogglebug-schem.pdf