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
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]
> > > >
> > >
> >
>
