Fw: simple schematics

[Harry Bissell]

Here's my spin on a pseudorandom generator I used to replace that gaddam MM5837
that they put in the Prophet V. $3,500 bucks and a noise generator that goes tic
tic tic... I DON'T THINK SO. Its based on a Popular Electronics design as credited
in the PCB drawing. I tried analog noise but it didn't work in the Pro V because
the design used the "rail to rail" output as a feature. This generator takes over
an hour to repeat. I never noticed any artifacts in the noise.

Everyone can use this design except Doepfer... :^)

Harry

Magnus Danielson wrote:

> From: KA4HJH <ka4hjh at gte.net>
> Subject: Re: Fw: simple schematics
> Date: Sun, 9 Jan 2000 19:03:54 -0500
>
> > >I would recommend using a different
> > >noise circuit, as the MM5837 noise has (for me...) a very apparent
> > >repetitive nature, due to an internal shift register which is not long
> > enough.
> >
> > Only 17 bits. If you're going to build one from discrete logic you
> > might as well go for 32. This was in Electronotes.
>
> In "The Art of Electronics" they say that the MM5437 is a 23 bit register
> device tapping at bit 18. They also say that the internal clock run at about
> 160 kHz.
>
> Doing both 35 and 39 is done by using 2 CMOS shift registers and any spare XOR
> gate available. That part of the curcuit goes in the el cheapo department.
> Some filtering and output curcuit is needed as well as some clock.
>
> Cheers,
> Magnus