[sdiy] CA3130 in Polyfusion Noise module...should a new one work?

[James Patchell]

The schematic is not OK...as drawn...the CA3130 stage will not work.

At 07:30 PM 12/21/2005 +0100, HA.Synth at t-online.de wrote:
>The  CA3130 is designed for unsymetric supply voltage. The schemo looks OK.
>The maximum voltage between +Ub and - Ub is 16V. If you tried it with more
>then +-8V symetrical then the OpAmp may be gone.  The negativ input voltage
>must not exceed -0,5V under -Ub at pin 4. The 3130 has problems with
>capacitiv load. I looked this up in an old book. The suffix E is not noted
>here.
>
>Try to replace it with a normal OpAmp (use symmetrical supply) to ensure that
>everithing else is working fine.
>
>Measure the input voltage/signal. If it exceeds -0,5V then this should be 
>your
>problem and damages the 3130
>
>HA
>
>
>Am Mittwoch 21 Dezember 2005 18:34 schrieb Rutger Vlek:
> > I was just wondering about the CA3130 op-amp. Has it changed since it was
> > first produced? I'm doing a remake of a Polyfusion Noise module and in the
> > first gain stage after the noise generating Diode (or transistor in my
> > case) a CA3130 is used. But in the schematics I found on internet
> > (synthfool.com) the CA3130 is powered with only +V and not with -V. Instead
> > pin 4 is connected to Ground.
> >
> > In my remake I couldn't get the CA3130 to work...and I don't know why.
> > Signal is going in, and the signal path after the output pin is correct
> > too, but somehow my Op-Amp won't amplify. That's very strange. In the
> > current datasheets on internet about the CA3130E by Intersil i read that it
> > does need a +V and -V, but when i tried it the chip ran very hot and
> > probably died. So i had to buy new ones.
> >
> > Is the op-amp configuration in the schematic
> > (http://www.synthfool.com/schematics/polynoise.gif) still working with the
> > newer CA3130's???
> >
> > Regards,
> >
> > Rutger

         -Jim
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