Hi
look at the FET, what kind are you using? right way around etc
some FETS wont work in these ccts.
Andrew
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]
> >
>
