MM5837?

[Harry Bissell]

Likewise I have a schematic for one that I adapted from Popular Electronics.... and
used
in the Prophet V to replace the... (gawdawful) ... chugga chugga unit ! will send
scan to
any who requests...

H^) harry

Magnus Danielson wrote:

> From: patchell <patchell at silcom.com>
> Subject: Re: MM5837?
> Date: Sat, 02 Sep 2000 12:22:18 -0700
>
> >     All I can say is, good luck.  In one of my home made synths, I am pretty
> > sure I have one of these things.  You might be able to talk me out of it as a
> > last resort (I personally don't really care much for it, you can hear it
> > repeat, if you listen really carefully).  These went out of production a long
> > time ago.  Keep me posted if you can't find one.
> >
> >     -Jim
> >
> > Romeo Fahl wrote:
> >
> > > Hello,
> > >
> > > I'm looking for an MM5837 ("Chugga Chugga") pseudo-random noise IC to do
> > > some experimenting with.  Does anyone have a spare or know of a source for
> > > one?
>
> Do you really require the MM5837? It is not too complex to cook up a noise
> source out of standard CMOS or TTL. If you go to the archives (Oh, I never
> thougth I would refer to them!) you will find a thread on the subject, I recall
> being part of it, I even posted a ASCII schematic in there...
>
> If you really want a a 17 stage noise source it should not be too difficult to
> make an equalent schematic, but a longer shifter is better. A 4006, a XOR gate
> of choice and some clock generator (two of the XOR gates could be used for
> that) and you have an equalent.
>
> The MM5837 is a 17 bit shift register with feedback at the 14th tap. The MM5837
> also has an internal oscillator which changes frequency with the supply power
> (obviously!). Getting something equalent should not be too hard. Actually,
> a 17-tap shift register is a bit too short... it will beat too obviously.
>
> Anyway for some more info, check out:
> http://www.vego.nl/8/18/8_18.htm
> http://www.io.com/~ritter/NOISE/NOISRC.HTM
>
> Cheers,
> Magnus