Rays "Pink enough for me" noise gen.

LektroiD

Is it possible to substitute the 2N2712 for a 2N3904? If so, I'll be looking at stripboarding this today. If not, what other possible equivalents are out there?

http://www.musicfromouterspace.com/analogsynth/rayspinknoise.html

magman · Joined: Feb 04, 2009 Posts: 363 Location: Liverpool, UK

I suspect it will work with a 2N3904, but I expect you won't get the same level of noise.

You could always try a few different NPN transistors to see which is the noisiest, or even a 9-12V zener, as Ray points out in his notes on the circuit diagram.

Regards

Magman

Rykhaard · Joined: Sep 02, 2007 Posts: 1290 Location: Canada

prgdeltablues · Posted: Tue Aug 17, 2010 1:33 am Post subject:

Remember also that 'best noise' isn't the same as 'most noise'. Looking on a scope, you want a good smooth band of noise, the actual voltage doesn't matter much, since you'll be amplifying it so much anyway. Some transistors are louder (higher noise voltages), but have spiky noise profiles, which aren't as random, and won't sound as good.

2N3904s have worked fine for me. Pick the best of half a dozen.

Peter

LektroiD · Posted: Wed Aug 18, 2010 8:19 pm Post subject:

It's all up and running now, although the pink side seems to be louder;

I substituted R3 (500Ω) for a 470Ω, although I doubt that would make any significant difference.

The only 4.7MΩ (R1/R7) resistors I could find were carbon, not metal film as suggested.

I also used a poly capacitor for C8 as I couldn't find a 1µF ceramic.

Or maybe pink noise is just meant to appear louder?

Nice little project though.