[sdiy] Unusual Noise circuit

[Scott Gravenhorst]

Interesting that there are resistors in series with the power terminals
of the first opamp.  I have no clue what that might accomplish besides
reducing the output swing and limiting output current.

However, the first opamp is running totally open loop.  I would guess
that the 1 meg resistors from each input to ground supply both thermal
noise (and offset balance?)  Or it might be a way to amplify the noise
generated within the opamp ??

Is this a resistor noise amplifier?  If so, can anyone comment on popcorn
noise from resistors?  My guess is that it's low or nonexistent.  Are the
1 meg resistors carbon?  I'd guess yes.

I'll bet that under the right conditions this circuit might provide radio
reception...


Romeo Fahl <rfahl at pdx.edu> wrote:
>Just for kicks I was poking around a japanese synth DIY forum, despite 
>the fact that I don't understand even a smidgin' of Kanji or 
>Japanese... anyway I came across this noise circuit:
>
>http://www.aleph.co.jp/~takeda/radio/work/noiz-schem.gif
>
>Which looks really odd to me seeing that there's no diode or transistor 
>being used as a noise source.
>
>I got to it from this article:
>
>http://analog-synth.jp/cgi/bbs02/flashbbs.cgi?id=&md=viw&no=5614&tn=5587
>
>Anybody know how well this would work?
>
>Romeo
>

---------------------------------------------------------
- Where merit is not rewarded, excellence fades.
- Hydrogen is pointless without solar.
- What good are laws that only lawyers understand?
- The media's credibility should always be questioned.
- The only good terrorist is a dead terrorist.
- Governments do nothing well, save collect taxes.

-- Scott Gravenhorst | LegoManiac / Lego Trains / RIS 1.5
-- Linux Rex         | RedWebMail by RedStarWare
-- FatMan: home1.gte.net/res0658s/fatman/
-- NonFatMan: home1.gte.net/res0658s/electronics/
-- Autodidactic Master of Arcane and Hidden Knowledge.