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<DIV><FONT face=Arial size=2>It must be this one:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2><A
href="http://www.musicfromouterspace.com/analogsynth/STATEVARVCFFEB2006/STATEVARVCFFEB2006.html">http://www.musicfromouterspace.com/analogsynth/STATEVARVCFFEB2006/STATEVARVCFFEB2006.html</A></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Since its the only one that will
oscillate.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>It should not be acting the way you have described.
You should only get oscillation near the end of the max resonance pot travel.
Are you certain that all component values are correct especially those around
the Res and COF pots. There are resistors in the circuit designed to limit
the voltage range that the pots can deliver (COF R1, R5) and (RES R48, R52). If
you need to adjust the range you can adjust them however when I tested this on
+/-12V and +/-15V and I saw normal behavior. Also check the values around the VC
resonance circuit. I'm not sure why you would be seeing what you've described
under normal circumstances. Unsoldered component? Unsoldered off-board wire?
Wrong value component?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Here are some troubleshooting
suggestions:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2><A
href="http://www.musicfromouterspace.com/analogsynth/troubleshoot.html">http://www.musicfromouterspace.com/analogsynth/troubleshoot.html</A></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Ray</FONT></DIV></DIV>
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style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=guatis@gmail.com href="mailto:guatis@gmail.com">Benjamín Velasco</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=synth-diy@dropmix.xs4all.nl
href="mailto:synth-diy@dropmix.xs4all.nl">Synth DIY List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, March 21, 2006 4:12
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [sdiy] Ray Wilson's SV VCF with
+-15V</DIV>
<DIV><BR></DIV>Hi you all!! I recently finished this module from Ray's
site using my +-15V PSU. I seems to work but the ranges of the pots are too
extreme. It starts to oscillate as soon as I start moving the resonance pot,
and also i cover the entire CutOff freq range near the center position of the
COff pot. Can anybody help me figuring out what values to change so the
response is like the +-12V version?. Or maybe it's simpler to use a couple of
voltage regulators to get +-12V??. Thanks!!! </BLOCKQUOTE></BODY></HTML>