Noisy Noise Generator : digital psuedo random noise

[Scott Bernardi]

I HAD access to them - I built my original synth between 1979 and 1981 (yeah,
I'm one of those old guys). At the time I was an engineer at Precision
Monolithics.  I left in 1982 and went into computer programming, but I did
manage to take a few hundred IC's from engineering runs with me. I still have
about a hundred OP-27's (I was one of the co-designers).
I almost wish I had stayed around at PMI - a few years after I left, SSM
starting making their chips at PMI. PMI was eventually acquired by Analog
Devices.
DACs, though - nowadays I have to buy them like everybody else. You can get a
DAC0808 for about $1.50 and I think that's worth the reduced parts count.

Here's my DIY synth page, if anyone's interested.
http://members.home.net/sbernardi/elec/ogee_home.html


Theo wrote:

> Suppose the circuit can do without the dac,
> all you want is noise, a R/2R network would do.
>
> Then again, it is nice to have free access to DACs 'n stuff (lucky bastard).
>
> Cheers Theo
>
> ----- Original Message -----
> From: Scott Bernardi <sbernardi at home.net>
> To: Synth-DIY list <synth-diy at node12b53.a2000.nl>
> Sent: Friday, October 20, 2000 3:10 PM
> Subject: Noisy Noise Generator : digital psuedo random noise
>
> > I had so much trouble getting rid of 60 cycle hum on an amplified
> > reverse biased transistor noise source that I went digital.  The circuit
> > at the URL below is a psuedo random source, the digital portion which is
> > based on a circuit from ElectroNotes.
> > http://members.home.net/sbernardi/elec/noise.html
> >
> > As an application of noise; input noise into a sample and hold and feed
> > that into the CV for a low pass filter. This is the effect used in ELP's
> > Karn Evil 9 (you know, "Welcome back my friends to the show that never
> > ends.....").
> >
> > --
> > Scott Bernardi
> > sbernardi at home.net
> >
> >

--
Scott Bernardi
sbernardi at home.net