[sdiy] analog vs digital noise generators

[Metrophage]

Noise generators were some of the very first circuits I ever made, as I
was determined to get some S&H random bleeping going on. IMO analog
noise circuits are slightly simpler to make. I have never made a CMOS
unit with many stages, but for just a few parts you have an analog
circuit which is as "random" as can be, with good distribution, and
sounds great. I have never had issues with transistors not producing
sufficient noise. I use 2N2712 and have yet to find a dud. Still, made
the circuits with 3 small 1-pin sockets for testing. If I like what I
hear, I can always lighly solder them in place.

Since I already have analog noise circuits, I have made digital noise
without concern for repitition. For instance, the MM5837 noise IC in my
MG-1 is very repetitive, even with an audible click - it sounds like a
badly spliced tape! For an audio source it would be dreadful, but for
modulation it is great. But then I am a bit of a hapless noodler, and I
find psuedo-random melodies entertaining. My other fave reason for
digital noise is that I think that changing the noise clock sounds
amazing, in a way which is hard for me to put into words. My first
circuit which I thought out completely myself, with no copying of
schematics, was a circuit which used an SN76477 as a shift-register
noise source, and I connected a dual op-amp somehow to scale and range
a control voltage. I still love my voltage-controlled digital noise,
but these days I'd just use regular CMOS ICs instead of the 76477, as
they are cheaper and more versatile.

YMMV
CJ

__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com