[sdiy] Vote for your favorite noise source

[Sowa Roman]

Briliant idea!
pseudo-random shif register, say 31-taps long,
with several sets of resistors at its outputs.
Each would make different FIR filter response, and
not limited to only white, pink, red, brown, etc (black? :>)
The only problem - 31 resistors for each response, or
rather trimpots as their values for sure won't hit E24.
And 31 may be too low to have good response at low
frequencies.
Anyway, I like the idea.

Roman

__-----Original Message-----
__From: René Schmitz [mailto:uzs159 at uni-bonn.de]
__Sent: Monday, May 13, 2002 4:06 PM
__To: Tim Ressel; Synth-Diy
__Subject: Re: [sdiy] Vote for your favorite noise source
__
__
__
__My favourite is the pseudo random shift register. 
__25bit (4015 + 4006) For a continuous output I have 
__fed the eight taps from the 4015 into a weighted summing 
__stage. A kind of digital filter, that derrives an output 
__dependant of the number of ones in that portion of 
__the shift register. 
__
__There is also a nice circuit in the Art of Electronics,
__(Laboratory noise generator) that implements a 32-order
__low pass filter, which should give a good smooth 
__gaussian distribution. 
__
__I think the 3db/oct filtering for pink noise could also 
__be implemented with digital filtering.
__
__Cheers,
__ René
__