<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD><TITLE>Re: [sdiy] Noise-generating ICs</TITLE>
<META http-equiv=Content-Type content="text/html; charset=us-ascii">
<META content="MSHTML 6.00.2800.1170" name=GENERATOR></HEAD>
<BODY>
<DIV><SPAN class=359112202-02092003><FONT face=Arial color=#0000ff size=2>Hi
Grant</FONT></SPAN></DIV>
<DIV><SPAN class=359112202-02092003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=359112202-02092003><FONT face=Arial color=#0000ff size=2>Not at
all, I appreciate your input. I did not consider that R5 would attenuate
the signal but rather only intended it to hold the high input impedance
non-inverting input from floating about. The frequency content of the noise
should improve (have more low end) with a larger R so I changed it to 1M.
I'll bet anything up to 10M would probably work as well.</FONT></SPAN></DIV>
<DIV><SPAN class=359112202-02092003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=359112202-02092003><FONT face=Arial color=#0000ff size=2>Thanks
for your observations.</FONT></SPAN></DIV>
<DIV><SPAN class=359112202-02092003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=359112202-02092003><FONT face=Arial color=#0000ff
size=2>Ray </FONT></SPAN></DIV>
<BLOCKQUOTE>
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B> Grant Richter
[mailto:grichter@asapnet.net]<BR><B>Sent:</B> Monday, September 01, 2003 12:33
PM<BR><B>To:</B> Ray Wilson<BR><B>Subject:</B> Re: [sdiy] Noise-generating
ICs<BR><BR></FONT></DIV>Are you sure you want R5 at 4.7K? Perhaps a typo for
4.7M?<BR><BR>As drawn, the circuit is feeding a 4.7 MEG source impedance into
a 4.7K receiver. Seems like it would form quite a voltage divider for the
zener noise signal.<BR><BR>Nice circuit, sorry to be a butt-in-ski.<BR>
<BLOCKQUOTE><BR><B>From: </B>"Ray Wilson" <rayw@csd.net><BR><B>Date:
</B>Mon, 1 Sep 2003 08:47:53 -0600<BR><B>To:
</B><synth-diy@dropmix.xs4all.nl><BR><B>Subject: </B>RE: [sdiy]
Noise-generating ICs<BR><BR></BLOCKQUOTE><BR>
<BLOCKQUOTE><FONT color=#0000ff><FONT size=2><FONT face=Arial>Robot Boy
(Your AOL box is full) regarding noise...<BR></FONT></FONT></FONT><BR><FONT
color=#0000ff><FONT size=2><FONT face=Arial>You want noise... Go
here:<BR></FONT></FONT></FONT><BR><FONT color=#0000ff><FONT size=2><FONT
face=Arial>http://atlas.csd.net/~rjwsoft/multinoisemodule_exp.html<BR></FONT></FONT></FONT><BR><FONT
color=#0000ff><FONT size=2><FONT face=Arial>Ray<BR></FONT></FONT></FONT>
<BLOCKQUOTE><FONT size=2><FONT face=Tahoma>-----Original
Message-----<BR><B>From:</B> owner-synth-diy@dropmix.xs4all.nl
[mailto:owner-synth-diy@dropmix.xs4all.nl]<B>On Behalf Of
</B>Robotboy8@aol.com<BR><B>Sent:</B> Sunday, August 31, 2003 7:43
PM<BR><B>To:</B> synth-diy@dropmix.xs4all.nl<BR><B>Subject:</B> [sdiy]
Noise-generating ICs<BR><BR></FONT><FONT face=Arial>Hi, I think this is my
first post but I've been lurking for months now.<BR>I'm looking to build
an electronic drumset using a noise source split into several identical
channels, filtered, and mixed back together. The trouble is, the
book I'm getting the basics out of (Build your Own Low-Cost Signal
Generator, by Delton T. Horn) lists two ICs for noise generation, the
MM5837N and the S2688, but a Googling shows that neither are easily
available. Can anyone here point me towards another suitable
IC?<BR>As background, I'm building a simple drum machine as a first sdiy
project (not very synth, i guess, but a good start). I haven't
purchased many components yet because I want to make sure they're all
available - so far, that's the only one that's not.<BR>Also, are there any
reasonable alternatives to optoisolators for voltage-controlled resistors?
How is voltage control usually handled in synths? (this one's been
bugging me for a looong
time...)<BR> -eric</FONT></FONT>
<BR></BLOCKQUOTE><BR></BLOCKQUOTE><BR></BLOCKQUOTE></BODY></HTML>