one/F noise source ckt?

[Osamu Hoshuyama]

Hello List members,

> Date:    Sun, 03 Sep 2000 20:55:31 +0200
> From:    Magnus Danielson <cfmd at swipnet.se>
> Well, I just checked the MiniMoog Service Manual and it is not something very
> clever, he just filters it. It is a fairly simple filter. It falls into one of
> those "good enougth" approximations.
> 
> The ASM-1 noise source has equalent complexity and similar design.

I agree with you.  For audio, these filters are sufficient
approximations.

If less error is needed, the following Japanese page on -3dB/oct
filter may be useful.  Not only circuit, but measured response are
there.  Even if you can't read Japanese, you can get sufficient
information from schematics. 

http://www.omninet.co.jp/workshop/analog/WHITPINK.HTM

In the following page, the simplest way to get pink noise is proposed.
It uses a MOS FET as the noise source.  Measured FFT result indicates
that the MOS FET generates almost perfect pink noise (1/f noise). 

http://www.omninet.co.jp/workshop/analog/PINK.HTM

Hope this helps.
- -- ---- ----------- --- --- - ----- -- --- --- - - ------ - - - --
 Osamu HOSHUYAMA          Digital Signal Processing Technology Group
                    C&C Media Research Laboratories, NEC Corporation
               Email: houshu at ccm.CL.nec.co.jp,  Fax: +81-44-856-2232
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