High Quality White Noise Gen

[Jim Slone]

What are the best options for high quality audio white noise
generation?

I have been using generic diodes and reversed biased transistors. Then
someone mentioned there are special parts available with better
characteristics.

Can anyone please give me a pointer?

Jim Slone

 

[E]

What are the best options for high quality audio white noise
generation?

You can buy a CD full of white noise.

-ek

 

[Dirk Bruere at NeoPax]

Racist!
We want Black noise.

(c)Rap

 

[[email protected]]

Then use some of Obama's speeches.

Ow!

 

[Don Klipstein]

Homophobe! We want Pink noise!

A link previously mentioned in this thread offered what they said
was "pink noise", along with "white noise" and "brown/red noise" IIRC.

I do get a little into a mood to test the "pink noise" to see if it is
"truly pink" as opposed to something towards "purple noise"... I hope
only as a result of some midrange frequency response dip in my computer
loudspeakers ("they are fairly-el-cheapo" that *may* accentuate "lower
treble" and "bass end of midrange").

 

[Paul Keinanen]

What are the best options for high quality audio white noise
generation?

A pseudo random noise (PRN) generator (a shift register and a few XOR
gates in the feedback path) will generate quite good white noise
sequences at frequencies well below the clock frequency.

 

[JosephKK]

Hmmm, you are right.... I still don't think that summing the voltage
noise from a bunch of unipolarized zeners is going to get rid of the
voltage assymetry. But I'd be happy to be wrong too. Have you ever
tried this? It would be simple enough to put 5 or 6 together and see
what the output looks like. (As long as you don't mind my summing
with an opamp)... Maybe I can find some 'fun' time on Friday.

George H.

Actually differencing them in twos, then summing seems more likely to
reduce the asymmetry.

 

[JosephKK]

The math says it must be so. Still, the sum would converge to Gaussian
faster if half of the lopsided signals were inverted.

And that is where you tripped yourself up. Sums of lopsided signals are
still lopsided. Differences may work better.

Zener noise gets more symmetric at higher currents. 10 mA is usually
OK for a small 10-volt zener.

Direct from the nature of the I-V curve.

I sometimes generate Gaussian-distributed numbers by summing a bunch
of RAN() calls, which are uniform on [0,1]. Six to ten works well, and
the crest factor is finite and known.

John

 

[oo pere oo]

Use
news.aioe.org

Thanks! Now I have real news again

Pere

 

[JosephKK]

Thanks! Now I have real news again

Pere

There is also eternal-september.org. Plus a few low cost commercial
providers, like where i post from.