Thanks for that Dave,
The problem I'm having right now is choosing the right digital
potentiometer for the job. The versions that I got as samples from
Maxim are only 5Volt operation. No good for the Poly because the audio
is 10V (-5<->+5).
Analog devices does one that is 10-30V but then the logic control is
difficult because it would "see" logic zero only at -5 volts which
doesn't match up the Poly either.
I have the same problem with the FM mod too because you want to be
able vary the amount of DCO that is injected into the VCF. Once again,
the range is -5<->+5.
So I am kinda scratching my head right now.
Mike.
--- In korgpolyex@yahoogroups.com, "David Mochen" <davidmochen@...> wrote:
>
> Hi
>
> Just a small note... Atom's great design has been tweaked a bit by
this guy Olaf, who replaced the 50k cutoff pot with a 100k pot for a
broader response. I am using 100k on my Poly and the sweeping range is
very very sweet. You might want to try 50k and 100k for your aTomaHawk
board :)
>
> Of course Mike, you might as well want to add a switch for toggling
on/off MoogSlayer. Olaf did this also via a hardware switch...
>
> thanks galore
>
> Dave
>
> ps: glad that the aTomaHawk moniker caught on! :D
>
> ----- Original Message -----
> From: korgpolyex800
> To: korgpolyex@yahoogroups.com
> Sent: Monday, March 17, 2008 2:21 PM
> Subject: [korgpolyex] Moog Slayer mod - question
>
>
> Hi Atom,
>
> I am working on the new aTomaHawk board mod kit and have a question
> for you.
>
> Is the only reason you replaced VR2 with a pot so that you could
> control VCF cutoff via a knob instead of via the VCF cutoff parameter?
>
> Because it appears to me that providing cut off control via the
> existing circuitry will work just fine. The goal is to provide a knob
> to control control cut off.
>
> Then, you replaced VR5 so that you could really push the resonance
> into self oscillation. That will definitely need a digital
> potentiometer put in its place. However, I am wondering why you use a
> log pot. I would have thought that the resonance response on the
> filter chip would have been linear. And you ground one side which is
> completely different to the way the trimmer is set up. Why?
>
> Thanks for your help,
>
> Mike.
>