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<DIV><FONT face=Arial size=2>Wow,</FONT></DIV>
<DIV><FONT face=Arial size=2>A lot of good information. Thank you all, I
guess I have a lot of homework to do!</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>Scott</FONT></DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2><FONT face=Arial
size=2>===================</FONT></FONT></DIV>
<DIV><FONT face=Arial size=2>Paul Perry wrote:</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>Analog Devices do some. But usually only surface
mount.<BR>For discrete compressors, check the guitar effect circuits<BR>(search
for "doctor Q")<BR></FONT></DIV>
<DIV><FONT face=Arial size=2>===================</FONT></DIV>
<DIV><FONT face=Arial size=2><BR>Craig Critchley wrote</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>That Corp. has the THAT4301 analog processor, which
contains an RMS<BR>detector, an exponential VCA and three opamps (one is
dedicated as a<BR>current-to-voltage converter for the VCA). The primary
purpose for it is<BR>audio compressors. Its several building blocks on a chip,
rather than a<BR>purpose-dedicated device, so it might be more
flexible.<BR><BR>Unfortunately That only sells multiples of 20 (one tube), and
they aren't<BR>distributed through any of the normal online distributors that
I'm aware of.<BR>They are also more expensive, in that quantity, that the SA571
price you<BR>found, but it is designed for audio rather than telecoms, so it may
have<BR>better specs.<BR><BR>Another possibility is Analog Devices's SSM2165 and
SSM2166, which are<BR>microphone preamps that include compressor circuits.
I think those can only<BR>be used as compressors, though, and I don't think
they're cheaper.<BR></FONT></DIV>
<DIV><FONT face=Arial size=2><FONT face=Arial
size=2>===================</FONT></FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>Steve Ridley wrote:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>There are better solutions than the NE571.
Take a <BR>look at:<BR><BR><A
href="http://www.thatcorp.com">www.thatcorp.com</A><BR><BR>and look at their
"Analog Engine" dynamic processors<BR>and application notes and design
notes. More info<BR>than you can shake a stick at. That Corporation
were<BR>formerly the semiconductor part of DBX, so they know<BR>a bit about
compression and noise reduction.<BR><BR>You could also look on the Perkin Elmer
(formerly Vactec)<BR>site. They make vactrols and have an extensive data
sheet<BR>on how to use them in dynamics control. Go to:<BR><BR><A
href="http://optoelectronics.perkinelmer.com">http://optoelectronics.perkinelmer.com</A><BR><BR>and
search for Vactrols.<BR><BR><BR></DIV></FONT></BODY></HTML>