Cgs synth

Did you connect pins 1 and 4 of the 311? There's a note on the PCB
page, but if you're like me you may have missed it.
This only applies to the Bridechamber version of the PCB, by the way.

Neither of you burned out your polystyrene cap, did you? I've done that
twice lately.

Scott Deyo
The Bridechamber
contact@...
http://www.bridechamber.com
Jealous Edison Record Kompany
http://www.jealousedison.com

On Dec 1, 2008, at 12:44 PM, casperelectronics wrote:

> Hey,
> thanks for the response! I discovered a huge problem. Somehow one of
> the traces on the board was cut and there was no ground connection to
> the 4051s or the 4024. Connecting fixed a few issues but had no
> noticeable effect on the VCO leak through problem.
> I checked the outs of the 4024 and I'm getting 3 clean square waves.
> One strange issue is that the VCO cuts off, just stops running at a
> high frequency ALMOST out of the audible range.
> When you turn it up to a certain point it cuts very noisy then just
> cuts off.
> Plus As I mentioned a bunch of times, I'm still getting strong bleed
> through.
> I've replaced every chip except the CA3140. I don't have a
> replacement for that. Could that be responsible for my cutoff problem?
> -pete
>
> On Dec 1, 2008, at 4:07 AM, andrewlistmayer wrote:
>
> > Mine isn`t working properly either, but based on what you said I`m
> > 99.9999% sure your isn`t either. The VCO is supposed to clock the
> > filter, so the frequency of the filter changes with it. When the
> > filter receives no clock from the VCO, it seems to lock to a fixed
> > frequency which is below the audible range. Mine did this before I
> > fixed the VCO. The reason you get a filter sweep in the last 20% of
> > the bandwidth knob is because you are simply increasing the band
> large
> > enough to let some audio through, while the center point still sits
> in
> > the sub audio range, so it`s acting like a normal lowpass filter. At
> > least that`s how I interpreted it when my VCO wasn`t working.
> >
> > Now, the VCO leaking through into the audio without clocking the
> > filter, that`s a new one to me. I`m no expert at this, so all I can
> > say is that it`s clear your filter and VCO are working, so your
> > problem mostly likely lies in the circuitry that is supposed to make
> > them work together. The filter is clocked by 3 outputs of the 4024,
> so
> > I`d check around there. Good luck.
> >
> > --- In cgs_synth@yahoogroups.com, casperelectronics <pete@...>
> wrote:
> > >
> > > Hello everyone.
> > > Sorry to continue the Bi-N-Tic questions. I know there have been a
> > > lot and I've read them all and I still have a few more.
> > > I think I got the whole thing working right but I'm not sure,
> it's a
> > > weird module (as I'm sure you'll all agree)
> > > The way it is working now it is really two modules, a filter and a
> > > VCO, but I don't see (or hear) much connection between the two.
> > >
> > > If I turn the coarse and fine tune knobs all the way down, there
> is
> > > no oscillator.
> > > Then if I feed a signal in the IN jack i can get some really nice
> > > filter cut sweeps using the BANDWIDTH knob and resonance using the
> > > DAMPER knob. The whole filter sweep is in the last 20% of turn of
> > > the bandwidth knob.
> > > As I turn UP the coarse tune, a square osc, mixes into the signal.
> > > It doesn't effect the filter, it just mixes into the audio path.
> > > When I turn it up almost beyond the audio range, the osc suddenly
> > > cuts off.
> > > Anyway.. maybe this is just how it works? I'd like to talk to
> > > someone who has built one or two of these so that I know if I
> should
> > > work on it some more.
> > > I really wish there was some kind of CV for filter cut. Am I
> missing
> > > something?
> > > Thanks!!!!
> > > -pete
> > >
> > >
> > >
> > >
> > >
> > > On Nov 28, 2008, at 9:54 PM, casperelectronics wrote:
> > >
> > > > Hey Scott,
> > > > I want to add the wave outputs on my bintic filter but I can't
> > find
> > > > the info.
> > > > Do you sell daughter boards/ host schematics for that on your
> > site??
> > > > Thanks!
> > > > -pete
> > > >
> > > >
> > >
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> >
> >
> >
>
> [Non-text portions of this message have been removed]
>
>
>

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