white/pink noise generator on a 9v supply

[redepoch7]

Is there a way to make a super simple white noise generator on a 9volt supply?

I noticed as well that most of the schematics (which were mostly 12 volts) had a dual supply. Is there a way to avoid that and still get the random white noise (pseudo-random is fine too)?

I don't really want to muck with the +/-9v because I don't really understand it.

Any help you could give would be great.

 

[redepoch7]

no sooner did I post this...

**broken link removed**
An audio noise generator capable of driving earphones or small speakers

And... I just threw it on a bread board... pure as the driven snow (audio snow that is).

I have no idea what the wave-form looks like or how good of a design this is but hey... it's a start.

I want add a sample and hold circuit to it so I can get a bunch of random boops and beeps.

Again, no idea if I am even on the right track but at least it's a start.

Any thoughts or ideas?

 

[audioguru]

The lousy old LM324 has such a poor high frequency response that the two in series, each with a voltage gain of 50 in that circuit will cut high frequencies at the output above only 5kHz. Audio goes up to 20kHz so two octaves are missing.

 

[redepoch7]

This was the only solution I could find.

Should I substitute the LM324 for something else using a variation on this schematic?

 

[audioguru]

I would use a much better TL072 dual opamp or TL074 quad opamp that have a bandwidth to 40kHz when the gain is 50. Two in series have a bandwidth to 20kHz.