Cgs synth

Are any of the middle pins on your PCB-mounted pots shorting with a
side pin? Sometimes the thicker upper part of the pin can touch the
extra pad next to it on the top-side of the board. I've never had it
happen, but someone else has.

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

On Oct 19, 2008, at 4:18 AM, andrewlistmayer wrote:

> Yes, at the low end of the coarse knob, the oscillator is already in
> the mid to high range. It does nothing til about 9 oclock then it gets
> higher, eventually getting so high around 1 oclock that it stops
> clocking the filter. The only wiring mistake I could see affecting
> this would be with the tune knobs, but they both have +/- 15 on either
> end and go to the coarse and fine tune pads on the PCB :S I've already
> checked the CV summing sections for continuity and values(though I
> didn't unsolder any of the resistors before measuring them) and didn't
> find any shorts. I tried adding bigger capacitors in parallel with the
> 2n2, but before I could get as low as what you might call a bass sound
> it stopped clocking the filter >_<
>
> --- In cgs_synth@yahoogroups.com, Scott Deyo <contact@...> wrote:
> >
> > So the frequency of the oscillator outputs is high, right?
> > I'm not sure what would cause that.
> > Any wiring mistakes? I usually try to make at least one on each
> Bintic
> > : )
> >
> > Scott Deyo
> > The Bridechamber
> > contact@...
> > http://www.bridechamber.com
> > Jealous Edison Record Kompany
> > http://www.jealousedison.com
> >
> >
> > On Oct 18, 2008, at 1:02 AM, andrewlistmayer wrote:
> >
> > > The filter sounds wild and wacky! Like a cross between hard sync
> and
> > > phasing, but it doesn't do much until the bandwidth is turned up
> > > pretty high, so I think it is supposed to be clocked slower. I
> turned
> > > the zero trimmer all the way down and that just increases the dead
> > > area at the beginning of the knob turn, before the frequency
> starts
> > > getting higher. I also tried applying negative CV; no dice. It
> doesn't
> > > want to go any slower :S
> > >
> > > --- In cgs_synth@yahoogroups.com, Scott Deyo <contact@> wrote:
> > > >
> > > > That is strange.
> > > > How does the filter section sound?
> > > >
> > > > Scott Deyo
> > > > The Bridechamber
> > > > contact@
> > > > http://www.bridechamber.com
> > > > Jealous Edison Record Kompany
> > > > http://www.jealousedison.com
> > > >
> > > >
> > > > On Oct 16, 2008, at 2:06 AM, andrewlistmayer wrote:
> > > >
> > > > > Doh! I just had to re-install that pesky resistor to get the
> > > filter
> > > > > clocking, but the minimum pitch of the oscillator is still
> very
> > > high,
> > > > > even after turning the zero trimmer all the way down.
> > > > >
> > > > > --- In cgs_synth@yahoogroups.com, "andrewlistmayer"
> > > > > <andrewlistmayer@> wrote:
> > > > > >
> > > > > > Ahh, thanks. Now it's oscillating alright, but really high
> > > pitched
> > > > > and
> > > > > > not affecting the filter section. I guess this means I have
> a
> > > > > > 4024-based problem. I'll look into it and collect some more
> > > data in
> > > > > > case I still need help.
> > > > > >
> > > > > > --- In cgs_synth@yahoogroups.com, Scott Deyo <contact@>
> wrote:
> > > > > > >
> > > > > > > Dang! I forgot about a little boo-boo on the PCB. Link
> +15V
> > > to pin
> > > > > 1 of
> > > > > > > the LM311 and you should be good to go.
> > > > > > > It's not connected to anything right now... sorry!
> > > > > > >
> > > > > > > Cheers,
> > > > > > > Scott Deyo
> > > > > > > The Bridechamber
> > > > > > > contact@
> > > > > > > http://www.bridechamber.com
> > > > > > > Jealous Edison Record Kompany
> > > > > > > http://www.jealousedison.com
> > > > > > >
> > > > > > >
> > > > > > > On Oct 15, 2008, at 2:21 AM, andrewlistmayer wrote:
> > > > > > >
> > > > > > > > I just read through this old thread because I have a
> similar
> > > > > problem
> > > > > > > > with my Bi-n-Tic. I can get a filter sweep out of the
> last
> > > 20%
> > > > > or so
> > > > > > > > of the bandwidth knob, but the tuning knobs do nothing.
> This
> > > > > leads me
> > > > > > > > to believe that the center frequency is stuck somewhere
> > > below
> > > > > the
> > > > > > > > audio range. So, I check the oscillator section. I also
> > > have a
> > > > > slight
> > > > > > > > amount of DC on pin6 of CA3140, so it isn't
> oscillating. I
> > > also
> > > > > have
> > > > > > > > voltage on pin 2, which is supposed to be at 0. Then, I
> > > start
> > > > > at the
> > > > > > > > beginning and try to figure out what is wrong. I can
> find no
> > > > > > faults in
> > > > > > > > the CV summing section, yet I only get between -.8 and
> > > barely
> > > > > > above 0v
> > > > > > > > depending on the coarse tune pot. Is this correct?
> Also, I
> > > am
> > > > > not
> > > > > > > > getting +15 on pin 1 of the LM311 like it shows on the
> > > > > schematic. The
> > > > > > > > datasheet tells me this is a ground pin, so I'm not
> sure how
> > > > > > important
> > > > > > > > this is. I'm using a PN4391 fet and I matched the G, S
> and
> > > D on
> > > > > the
> > > > > > > > PCB with the pinout on the fairchild datasheet. One last
> > > thing
> > > > > to
> > > > > > note
> > > > > > > > is that I'm using the bridechamber PCB. I didn't know
> what
> > > to do
> > > > > > about
> > > > > > > > the 100k resistor marked with a star, so I installed,
> then
> > > > > removed it
> > > > > > > > afterwards.
> > > > > > > >
> > > > > > > > I'm stumped at this point, so any hints would be greatly
> > > > > appreciated.
> > > > > > > >
> > > > > > > > --- In cgs_synth@yahoogroups.com, sasami@ wrote:
> > > > > > > > >
> > > > > > > > > Check your capacitor too. Make sure it is the right
> size.
> > > > > Make sure
> > > > > > > > it is
> > > > > > > > > actually soldered in - no bad joints, or not between
> the
> > > wrong
> > > > > > > > holes. there
> > > > > > > > > is a spare hole there to allow for different sizes.
> If you
> > > > > have
> > > > > > the
> > > > > > > > cap
> > > > > > > > > between two the holes that are joined by the
> trackwork, it
> > > > > isn't
> > > > > > > > going to work.
> > > > > > > > >
> > > > > > > > > Also note that the pin-outs of different FETs varies.
> If I
> > > > > use the
> > > > > > > > 2n4091, I
> > > > > > > > > need to install it "backwards" to the marking on the
> PCB.
> > > > > > > > >
> > > > > > > > > Ken
> > > > > > > > >
> > > > > > > > > >So, if the voltage on pin 2 & 3 is 0V and the 3140
> gets
> > > it's
> > > > > > > > > >powersupply, it should create some AC voltage on pin
> 6 ?
> > > > > > > > > >I have only a DC voltage that varies between 0 &
> 0.86 VDC
> > > > > > > > (depending
> > > > > > > > > >on the position of the coarse frequency pot )
> > > > > > > > > >
> > > > > > > > > >thanks again for your help !
> > > > > > > > > >steven
> > > > > > > > > >
> > > > > > > > > >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
> > > > > > > > > >>
> > > > > > > > > >> You should never see any voltage on pin 2 of the
> 3140
> > > - it
> > > > > is a
> > > > > > > > > >summing
> > > > > > > > > >> node. It is a basic op-amp feedback loop. Yhe opamp
> > > > > devotes its
> > > > > > > > > >entire time
> > > > > > > > > >> truing to keep pins 2 and 3 at exactly the same
> > > voltage. As
> > > > > > pin 3
> > > > > > > > > >is 0v, pin
> > > > > > > > > >> 2 will be 0v. The current through the point will of
> > > course
> > > > > vary
> > > > > > > > as
> > > > > > > > > >the
> > > > > > > > > >> output of the op-amp fights the current drawn
> through
> > > the
> > > > > LM394
> > > > > > > > > >(through the
> > > > > > > > > >> integrating capacitor and through the FET during
> > > reset).
> > > > > > > > > >>
> > > > > > > > > >> Ken
> > > > > > > > > >>
> > > > > > > > > >> >hello,
> > > > > > > > > >> >no luck so far, I've replaced the 2N4391 fet, but
> > > still no
> > > > > > > > > >voltage
> > > > > > > > > >> >on pin 2 of the ca3140. I've also measured with a
> > > scope
> > > > > to see
> > > > > > > > > >what
> > > > > > > > > >> >is exactly the output on pin 6 of the ca3140, and
> it
> > > shows
> > > > > > only
> > > > > > > > a
> > > > > > > > > >dc
> > > > > > > > > >> >voltage ( 0.86 V )
> > > > > > > > > >> >
> > > > > > > > > >> >any more clues ?
> > > > > > > > > >> >many thanks in advance !
> > > > > > > > > >> >steven
> > > > > > > > > >> >
> > > > > > > > > >> >--- In cgs_synth@yahoogroups.com, "stiebz"
> > > > > <theevaporizer@>
> > > > > > > > wrote:
> > > > > > > > > >> >>
> > > > > > > > > >> >> hey,
> > > > > > > > > >> >>
> > > > > > > > > >> >> I used a 2n4391, I have no clue how I can check
> if
> > > it
> > > > > > still is
> > > > > > > > > >> >> working properly, so I'll try to replace this
> > > > > compontent to
> > > > > > > > see
> > > > > > > > > >if
> > > > > > > > > >> >it
> > > > > > > > > >> >> makes a difference.
> > > > > > > > > >> >>
> > > > > > > > > >> >> thanks,
> > > > > > > > > >> >> steven
> > > > > > > > > >> >>
> > > > > > > > > >> >> --- In cgs_synth@yahoogroups.com, "bbluthang"
> > > > > <jumpswine@>
> > > > > > > > > >wrote:
> > > > > > > > > >> >> >
> > > > > > > > > >> >> > Hi
> > > > > > > > > >> >> > look at the FET, what kind are you using?
> right
> > > way
> > > > > around
> > > > > > > > etc
> > > > > > > > > >> >> > some FETS wont work in these ccts.
> > > > > > > > > >> >> > Andrew
> > > > > > > > > >> >> >
> > > > > > > > > >> >> >
> > > > > > > > > >> >> > --- In cgs_synth@yahoogroups.com, "stiebz"
> > > > > <theevaporizer@>
> > > > > > > > > >> >wrote:
> > > > > > > > > >> >> > >
> > > > > > > > > >> >> > > unfortunately my bintic filter is still not
> > > > > working...
> > > > > > > > > >> >> > > I've replaced the tl072, ca3140 and the
> lm394,
> > > but
> > > > > still
> > > > > > > > > >the
> > > > > > > > > >> >> > > oscillator part is not working as expected.
> > > > > > > > > >> >> > > I've noticed that depending on the setting
> of
> > > the
> > > > > > > > frequency
> > > > > > > > > >> >> coarse
> > > > > > > > > >> >> > > pot, I have different readings on the
> circuit.
> > > > > > > > > >> >> > > I've added here a link to a part of the
> circuit
> > > > > diagram
> > > > > > > > > >where
> > > > > > > > > >> >> I've
> > > > > > > > > >> >> > > indicated some measurements done in both
> > > minimum and
> > > > > > > > > >maximum
> > > > > > > > > >> >> > > position of the frequency coarse potmeter. I
> > > hope
> > > > > > somebody
> > > > > > > > > >can
> > > > > > > > > >> >> give
> > > > > > > > > >> >> > > me clue where more or less the problem
> should be
> > > > > with
> > > > > > this
> > > > > > > > > >> >data.
> > > > > > > > > >> >> > > Thanks a lot in advance, you can find the
> > > drawing
> > > > > here :
> > > > > > > > > >> >> > >
> > > > > http://users.telenet.be/theevaporizer/modular/bintic.GIF
> > > > > > > > > >> >> > >
> > > > > > > > > >> >> > > steven
> > > > > > > > > >> >> > >
> > > > > > > > > >> >> > >
> > > > > > > > > >> >> > > --- In cgs_synth@yahoogroups.com, Romeo Fahl
> > > > > <rfahl@>
> > > > > > > > wrote:
> > > > > > > > > >> >> > > >
> > > > > > > > > >> >> > > > one thing to keep in mind is that CA3140s
> are
> > > > > super
> > > > > > > > > >delicate
> > > > > > > > > >> >> ICs.
> > > > > > > > > >> >> > > > They are very sensitive to static, but it
> > > wouldn't
> > > > > > > > > >surprise
> > > > > > > > > >> >me
> > > > > > > > > >> >> if
> > > > > > > > > >> >> > > > hooking up power in reverse was too much
> for
> > > it to
> > > > > > > > handle.
> > > > > > > > > >> >> > > >
> > > > > > > > > >> >> > > > Romeo
> > > > > > > > > >> >> > > >
> > > > > > > > > >> >> > > >
> > > > > > > > > >> >> > > > On Nov 4, 2006, at 6:08 AM, stiebz wrote:
> > > > > > > > > >> >> > > >
> > > > > > > > > >> >> > > > > No chips are hot ( and nothing smells
> > > burned )
> > > > > > > > > >> >> > > > > The TL072 seems to working fine, output
> 7
> > > > > follows the
> > > > > > > > > >> >> frequency
> > > > > > > > > >> >> > > > > settings, but on the CA3140 I always
> measure
> > > > > 0.56
> > > > > > V on
> > > > > > > > > >pin
> > > > > > > > > >> >2
> > > > > > > > > >> >> and
> > > > > > > > > >> >> > > 1.1
> > > > > > > > > >> >> > > > > V on pin 6 regardless of the frequency
> > > setting.
> > > > > Would
> > > > > > > > > >this
> > > > > > > > > >> >> > > indicate
> > > > > > > > > >> >> > > > > a faillure on the CA3140 or the LM394 ?
> > > > > > > > > >> >> > > > > thanks !
> > > > > > > > > >> >> > > > > steven
> > > > > > > > > >> >> > > > >
> > > > > > > > > >> >> > > > > --- In cgs_synth@yahoogroups.com,
> sasami@
> > > wrote:
> > > > > > > > > >> >> > > > > >
> > > > > > > > > >> >> > > > > > Test #1 - feel if any chip is getting
> > > hot. If
> > > > > > it is,
> > > > > > > > > >> >> replace
> > > > > > > > > >> >> > > it.
> > > > > > > > > >> >> > > > > >
> > > > > > > > > >> >> > > > > > Ken
> > > > > > > > > >> >> > > > > >
> > > > > > > > > >> >> > > > > > >when i wanted to test my bin-n-tic, i
> > > > > incidently
> > > > > > > > > >> >switched
> > > > > > > > > >> >> +
> > > > > > > > > >> >> > > and -
> > > > > > > > > >> >> > > > > > >power supply. after i fixed the
> problem,
> > > I
> > > > > have no
> > > > > > > > > >sound
> > > > > > > > > >> >> > > > > whatsoever.
> > > > > > > > > >> >> > > > > > >I measured 1.1 volt between pin6 of
> the
> > > > > ca3140.
> > > > > > > > > >> >> > > > > > >Is there any part(s) that is the most
> > > likely
> > > > > to be
> > > > > > > > > >> >> damaged ?
> > > > > > > > > >> >> > > > > > >thx,
> > > > > > > > > >> >> > > > > > >steven
> > > > > > > > > >> >> > > > > > >
> > > > > > > > > >> >> > > > > > >--- In cgs_synth@yahoogroups.com,
> > > "kopernig"
> > > > > > > > > >> ><6079smith@>
> > > > > > > > > >> >> > > wrote:
> > > > > > > > > >> >> > > > > > >>
> > > > > > > > > >> >> > > > > > >> yes, i noticed the diode and put
> in a
> > > > > jumper...
> > > > > > > > > >but
> > > > > > > > > >> >> still no
> > > > > > > > > >> >> > > > > joy. i
> > > > > > > > > >> >> > > > > > >> don't have a scope (yet) but the
> > > voltage
> > > > > on pin
> > > > > > > > > >six
> > > > > > > > > >> >of
> > > > > > > > > >> >> the
> > > > > > > > > >> >> > > > > ca3140
> > > > > > > > > >> >> > > > > > >is
> > > > > > > > > >> >> > > > > > >> just under 1 volt. with an audio
> probe
> > > i
> > > > > can
> > > > > > > > > >(barely)
> > > > > > > > > >> >> hear
> > > > > > > > > >> >> > > a cv
> > > > > > > > > >> >> > > > > > >click.
> > > > > > > > > >> >> > > > > > >> so the vco is not oscillating. i
> can't
> > > > > > figure out
> > > > > > > > > >why
> > > > > > > > > >> >> the
> > > > > > > > > >> >> > > 2n2
> > > > > > > > > >> >> > > > > > >> capacitor seems to be shorted...
> > > there's no
> > > > > > > > > >> >resistance
> > > > > > > > > >> >> > > between
> > > > > > > > > >> >> > > > > the
> > > > > > > > > >> >> > > > > > >> source and drain of the fet.
> nothing is
> > > > > > > > physically
> > > > > > > > > >> >> shorted.
> > > > > > > > > >> >> > > a
> > > > > > > > > >> >> > > > > dead
> > > > > > > > > >> >> > > > > > >> fet? any ideas?
> > > > > > > > > >> >> > > > > > >> andrew.
> > > > > > > > > >> >> > > > > > >>
> > > > > > > > > >> >> > > > > > >
> > > > > > > > > >> >> > > > > > >
> > > > > > > > > >> >> > > > > > >
> > > > > > > > > >> >> > > > > > >
> > > > > > > > > >> >> > > > > > >
> > > > > > > > > >> >> > > > > > >The CGS Modular Synth home page:
> > > > > > > > > >> >http://www.cgs.synth.net/
> > > > > > > > > >> >> > > > > > >
> > > > > > > > > >> >> > > > > > >Yahoo! Groups Links
> > > > > > > > > >> >> > > > > > >
> > > > > > > > > >> >> > > > > > >
> > > > > > > > > >> >> > > > > > >
> > > > > > > > > >> >> > > > > > >
> > > > > > > > > >> >> > > > > > >
> > > > > > > > > >> >> > > > > >
> > > > > > > > > >> >> > > > >
> > > > > > > > >
> > > >__________________________________________________________
> > > > > > > > > >> >> > > > > __
> > > > > > > > > >> >> > > > > > Ken Stone sasami@
> > > > > > > > > >> >> > > > > > Modular Synth PCBs for sale
> > > > > > > > > >> >> > > > > <http://www.blaze.net.au/~sasami/synth/>
> > > > > > > > > >> >> > > > > > Australian Miniature Horses & Ponies
> > > > > > > > > >> >> > > > > <http://www.blaze.net.au/~sasami/>
> > > > > > > > > >> >> > > > > >
> > > > > > > > > >> >> > > > >
> > > > > > > > > >> >> > > > >
> > > > > > > > > >> >> > > > >
> > > > > > > > > >> >> > > >
> > > > > > > > > >> >> > > >
> > > > > > > > > >> >> > > >
> > > > > > > > > >> >> > > > [Non-text portions of this message have
> been
> > > > > removed]
> > > > > > > > > >> >> > > >
> > > > > > > > > >> >> > >
> > > > > > > > > >> >> >
> > > > > > > > > >> >>
> > > > > > > > > >> >
> > > > > > > > > >> >
> > > > > > > > > >> >
> > > > > > > > > >> >
> > > > > > > > > >> >
> > > > > > > > > >> >The CGS Modular Synth home page:
> > > http://www.cgs.synth.net/
> > > > > > > > > >> >
> > > > > > > > > >> >Yahoo! Groups Links
> > > > > > > > > >> >
> > > > > > > > > >> >
> > > > > > > > > >> >
> > > > > > > > > >> >
> > > > > > > > > >> >
> > > > > > > > > >>
> > > > > > > > >
> > > >__________________________________________________________
> > > > > > > > > >__
> > > > > > > > > >> Ken Stone sasami@
> > > > > > > > > >> Modular Synth PCBs for sale
> > > > > > > > > ><http://www.blaze.net.au/~sasami/synth/>
> > > > > > > > > >> Australian Miniature Horses & Ponies
> > > > > > > > > ><http://www.blaze.net.au/~sasami/>
> > > > > > > > > >>
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > >The CGS Modular Synth home page:
> > > http://www.cgs.synth.net/
> > > > > > > > > >
> > > > > > > > > >Yahoo! Groups Links
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > >
> __________________________________________________________
> > > > > > > > > Ken Stone sasami@
> > > > > > > > > Modular Synth PCBs for sale
> > > > > > <http://www.blaze.net.au/~sasami/synth/>
> > > > > > > > > Australian Miniature Horses & Ponies
> > > > > > > > <http://www.blaze.net.au/~sasami/>
> > > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > >
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> > > > >
> > > > >
> > > > >
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> > [Non-text portions of this message have been removed]
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