Dieter-
Looks like he also made a "Euro" version that has multiple PCB's and
allows the polarity switching on each output column individually which
is even more useful at the expense of extra switches of course.

http://www.cgs.synth.net/modules/cgs33_matrix_mixer_euro.html

-James

On Dec 4, 2008, at 11:42 AM, James Husted wrote:

> Dieter-
> Ken Stone's Matrix mixer does the inversion thing without the multi-
> taped center terminal pots. His design is shown here:
> http://www.cgs.synth.net/modules/cgs33_matrix_mixer.html
>
> He has a switch to turn it from normal (off-on) to Bi-polar (full
> inverted-off-full non inverted) which is very nice. You may be able to
> avoid the expensive pots my using some of his ideas (in your own
> circuit of course). Maybe a taper can be found that would leave a wide
> "off" zone and then no detent would be needed either (especially if
> the mode can be switched from bi-polar to normal - the detent would be
> odd in the normal mode)
>
> I was wrong about the Buchla 205 - Looking at the schematics it
> appears to not do the inverting bit. That is a very nice function but
> if the cost/availability
> of the pots is a problem, the "normal" version is still quite usefull.
> -james
>
> On Dec 4, 2008, at 11:13 AM, yahoo@... wrote:
>
> > > I would like to see a 5x5 matrix mixer built around the Buchla 205
> > > design. Each crosspoint would go from off, to full on, to full
> > > inverted. Designed to pass audio or CVs. I know this module would
> > not
> > > be cheap because of the 25 pots, but it would be a very powerful
> > > module for performance and patch building. I have the schematic
> and
> > > parts kicking around but would love to see a true Doepfer unit and
> > not
> > > some DIY panel loudly sticking out of my rig like a sore thumb.
> > >
> > > -James
> >
> > Exactly this module will be released next year. Our only problem is
> > that we
> > could not find the potentiometers we want to use with center detent
> > and
> > center terminal (not the version used e.g. in the A-188-2 or A-138d
> > but the
> > horizontal version with the axis at right angle to the pcb). This is
> > why
> > it's not yet shown in the future modules list so far. Without center
> > detent
> > and center terminal it's hard to find the zero position and I think
> > that's
> > essential for a mixer with polarizer function. The simple version
> > (only
> > attenuators, no polarizers) could be released very soon as this is
> > already
> > available as a working prototype. But we want to try to find a
> > manufacturer
> > who is able to produce the desired potentiometer with center detent
> > and
> > center terminal. And the price will be not too much as all parts are
> > located
> > on one pcb only (that's why we need the horizontal version of the
> > potentiometers). I think it will be in the Euro 100...150 range.
> >
> > Best wishes
> > Dieter Doepfer
> >
> >
> >
>
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>
>
>



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