[sdiy] Source for center tapped pots? Anyone?

[john mahoney]

> > Me too!  I'd love to find some center-tapped linear pots that also have
> > mechanical center detent.  Preferably in 50K or 100K values.  These
would be great
> > for +/- modulation amount controls.  The center tap would allow you to
get a
> > true zero point in the center.
>
>  Exactly, I got the idea from the env intensity control on the VCF of the
> PolySix which I think is a brilliant and powerful single knob control, so
I want
> at least one of these on my EG module and would need another dozen or
> so elsewhere in the synth.
[snip]
>  I really only wonder about the price. If there's interest among other
> listmembers maybe we could agree on a "standard type" and get a bigger
> order volume for a better price. I was thinking about 200K lin pots with
> the center tap so each half turn would function like a 100K lin pot.


Follow the clicking mouse...

Peter Grenader designed a tiny little circuit for adding this
inverting/attenuating function wherever you wish:
http://www.buzzclick-music.com/gizmotron.html.
Peter says, "The Gizmotron PCB was designed specifically for the same 50k
linear Panasonic pots used by Blacet (Digikey part number P3T9503-ND)."

So, off to Digikey for more info... Okay, here it is:

Only 5K thru 50K values are available for these pots. 503 in the part number
means 50K. Note that "-ND" does not mean "no detent."

Digikey part P3T9503-ND has no detent.
Digikey part P3R7503-ND is the same pot with a center detent.

Hope this helps!
--
john

P.S. The Mono/Poly has an "invertenuator" on it's VCF EG input, too. Yes,
it's a great feature!