[sdiy] Polymoog resonator question
quincas at gmail.com
Sat Oct 6 00:33:56 CEST 2018
David, great idea, there should be more resonators in modular, IMO.
I just reviewed the one Andrew of Non Linear Circuits designed based on the
Korg PS3100. Vactrols for Freq control, simple and juicy :)
On Fri, Oct 5, 2018 at 2:24 PM Ian Fritz <ijfritz at comcast.net> wrote:
> Will this be a commercial product?
> > On Oct 5, 2018, at 12:54 PM, David G Dixon <dixon at mail.ubc.ca> wrote:
> > Thanks, Don. That's what I figured. I have removed CD4000 switches from
> > many designs and replaced them with DG400 switches for that very reason.
> > I'm going to redesign this Polymoog Resonator, using 2164s for the R's,
> > putting the stages under voltage control, and changing the output
> > situation a fair bit. I'm still not sure what I'm going to do about the
> > loop gain situation. I'm deriving the transfer function right now to
> get a
> > better idea of what it actually does.
> >> -----Original Message-----
> >> From: Donald Tillman [mailto:don at till.com]
> >> Sent: Thursday, October 04, 2018 11:04 PM
> >> To: David G Dixon
> >> Cc: synth-diy at synth-diy.org
> >> Subject: Re: [sdiy] Polymoog resonator question
> >>> On Oct 4, 2018, at 9:57 PM, David G Dixon <dixon at mail.ubc.ca> wrote:
> >>> I did have one other question, though...
> >>> What is the significance of "V_CH" which seems to play the
> >> role of ground almost everywhere in the schematic? Is this
> >> some specific voltage which is not 0V?
> >> Indeed, V_CH is 4.85 V.
> >> That audio section uses CMOS CD4000 series chips for audio
> >> switching. Those max at 18V. So the Polymoog runs the CMOS
> >> at 0 to +15V, and biases the audio signals up a little to fit
> >> in there.
> >> The alternative would be to leave the audio centered around
> >> 0V, and run the CMOS at something like +/- 5V. Then all the
> >> logic lines would have to be shifted. Which is a drag, but
> >> would have been better for audio quality.
> >> -- Don
> >> --
> >> Donald Tillman, Palo Alto, California
> >> http://www.till.com
> > _______________________________________________
> > Synth-diy mailing list
> > Synth-diy at synth-diy.org
> > http://synth-diy.org/mailman/listinfo/synth-diy
> Synth-diy mailing list
> Synth-diy at synth-diy.org
Synth Diy Guy
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the Synth-diy