Noisy noise generator

[Tony Allgood]

I have just been trying to get a decent noise generator for one of my
modules. I tried all sorts of designs and in the end I came up with the
classic reversed biased transistor. I tried zeners, even noise diodes,
and I found that the best noise was a BC549. Circuit to come later...
although there's nothing new here.

But the weirdest thing was that I really liked the noise coming out of a
10V 300mW zener. Good level and clear sound with no popping. I tried a
whole load of them, from different batches too, and I was very
impressed. So the next day, I tried a few more just to be sure. Odd...
all noise levels were seriously down on the previous night's. And it
varied over a period of a few minutes. Pseudo random sequences from a
diode?? :-) The I got it... as the sun went behind a cloud the noise
increased. In the dark, it went very high, almost three times the peak
value. I thought about painting them black or even using larger devices
in the epoxy cases... but the BC548s beckoned. UV light must be the key
here...

Regards,

Tony Allgood  Penrith, Cumbria, England

Oakley Modular Synth and TB3030:
www.techrepairs.freeserve.co.uk/projects.htm
My music: www.mp3.com/taklamakan