[sdiy] Adding CV jacks to a synth...

[harrybissell]

DTK wrote:

> One of the things I'm puzzling over -  the filter cutoff slider on my board
> has a voltage range of -12v to 12v.  I'm thinking that simply inserting an
> input on that circuit would cut out the bottom part of the range... it would
> only work from 0v to 12v. Is that right, or have I totally missed the mark?
>

That depends on exactly how the circuit works.  If you assume that the top of
the
pot is wired to +12... and the bottom to -12... if you break the connection to
-12 the whole pot is pulled UP to +12 and the input may not work at all.

Better would be to see where the wiper goes.  Assuming that it goes into some
series
resistor and then into the filter (maybe opamp?) control... you might ADD
another, equal
value resistor and run your external jack to that.  Then the slider will still
function AND the
added input will add or subtract from the filter CV... probably closer to what
you want
anyway.

what schematic you looking at ? isit online... we could chat more...   ;^P

H^) harry