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Cgs synth

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Re: Cynare filter problem

2008-09-15 by Dave

I am wondering whether I put the transistors in the right way. I am
using TO92 style trans that are black plastic with one flat side.
Right now I have all the 2N2222 and the 2N2907 trans facing the same
way with the flat part facing up towards the BP HP and LP holes. Is
this correct?

Thanks,
Dave


--- In cgs_synth@yahoogroups.com, Scott Deyo <contact@...> wrote:
>
> The CV pot is wired the way you say, but terminal 3 is also wired to
> ground. (i.e., it's wired as an 'attenuator' or voltage divider -- good
> to remember, they're common).
>
> The wiring diagram looks good for freq and res.
>
> Everything has the right orientation -- transistors, diode,
> electrolytics, TL071? The TL071 isn't a TL072? Did you install on the
> links on the board? (I've missed one a few times before.)
> For me, it's usually something painfully obvious once I see it, but for
> some reason I just can't see it though I've looked at it ten times.
> Especially on a single-sided board, make sure all your soldering is OK.
> One weak connection can wreak havoc.
>
>
> Scott Deyo
> The Bridechamber
> contact@...
> http://www.bridechamber.com
> Jealous Edison Record Kompany
> http://www.jealousedison.com
>
>
> On Sep 15, 2008, at 1:17 AM, Dave wrote:
>
> > Hi Scott,
> >
> > Thanks for the confirmation about the switch wiring :) I'm gonna
> > rewire the Decay an Damper pots too. I've tried various switch
> > setting from all off to individual on to all on and they all
react the
> > same to the resonance pot.
> >
> > Is it possible that the wiring diagram is wrong for the res or freq
> > pots? The freq pot wiring seems a little strange compared to the rest
> > with the 3 leg of the pot wired to the ferrite bead.
> >
> > While I'm at it how do I wire the VCF CV pot? Do I wire from EX to
> > the middle lug of the pot and then from terminal 1 on the pot to the
> > jack?
> >
> > Thanks,
> > Dave
> >
> > --- In cgs_synth@yahoogroups.com, Scott Deyo <contact@> wrote:
> > >
> > > I think Decay and Damper are backwards on the CGS diagram.
> > >
> > > It just occured to me that my panel's envelope pot is labeled
wrong!
> > > Instead of 0 to 10, it should read -5 to +5. It should be at 0 in
> > the
> > > middle, negative envelope to left, positive to right. Ugh!
> > > : (
> > >
> > > It sounds like you have the switches wired up correctly. Try
> > testing it
> > > with just lowpass on at first, and checking the resonance again.
> > >
> > > Cheers,
> > > Scott Deyo
> > > The Bridechamber
> > > contact@
> > > http://www.bridechamber.com
> > > Jealous Edison Record Kompany
> > > http://www.jealousedison.com
> > >
> > >
> > > On Sep 14, 2008, at 11:11 PM, Dave wrote:
> > >
> > > > Hi all,
> > > >
> > > > I just finished building a cynare :) But am having problems with
> > > > the filter section. I am building a kit supplied by bridechamber
> > > > which has three separate SPDT switches for the filter types. I
> > have
> > > > added the 6 pots for the osc and also added the impact gen
mod to
> > it
> > > > too (I subbed in a 100k pot for the 25k for now until I can get
> > the
> > > > 25k pot). These mods seem to work correctly. I also changed the R
> > > > gain resistor to 1.5k instead of the 10k.
> > > >
> > > > I followed the CGS wiring diagram exactly assuming that the pot
> > > > shafts are facing away from me and CW is 3 (I am not sure about
> > this).
> > > > One strange thing I noticed with this is that the Decay and
Damper
> > > > pots seem wired backwards so that as I turn it from 0 to 10 the
> > decay
> > > > shortens for both, I would think it should lengthen the decay as
> > you
> > > > turn the pot towards 10. The tone or balance between noise and
> > > > shimmer operates correctly.
> > > >
> > > > The problem with the filter is that the filter sweep is minimal
> > > > in effect, the envelope affects the impact sound strangely, when
> > in
> > > > the middle (5) there is little to no impact sound and when at
> > either 0
> > > > or 10 the impact is back (sweeping the impact pot mod changes the
> > > > character of the impact sound). The resonance pot is also acting
> > very
> > > > strange. I have wired the three switches as best I
> > > > knew how which is took the LP, BP, and HP and wired them to the
> > bottom
> > > > lugs of three switches then I wired some bus wire across the
three
> > > > middle lugs of the switches and attached the common wire to
that.
> > I
> > > > don't know if that is correct but it makes sense to me. When I
> > switch
> > > > between the filter types I can hear changes in tone that
> > corresponds
> > > > to the filter type.
> > > >
> > > > Did I wire the three switches correctly, if not how should I do
> > this?
> > > >
> > > > The main malfunction seems to come from the resonance pot. It
does
> > > > not increase the resonance and when I turn it all sound going
> > through
> > > > the filter is silenced for about 1-2 seconds and then comes back
> > again
> > > > with no change regardless of whether it is at 0 or 10.
> > > >
> > > > I'm new to the DIY so I don't want to mess with things too much
> > > > while trouble shooting, so I've gone over the board looking for
> > shorts
> > > > and poor connections but have not found anything yet, should
I try
> > > > changing some of the wires around on the res pot or maybe the
freq
> > > > pot? I'm confused as to why the decay and damper seem to operate
> > > > backwards from convention and am wondering if I got these wired
> > > > backwards maybe I wired the res or freq pots backwards but I've
> > > > checked over and over again and they match up to kens diagram...
> > > >
> > > > Sorry for the long post :) Any help would be greatly appreciated,
> > > >
> > > > Thanks,
> > > > Dave
> > > >
> > > >
> > > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> >
> >
> >
>
> [Non-text portions of this message have been removed]
>

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