<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
<HTML>
<HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=windows-1252">
<META NAME="Generator" CONTENT="MS Exchange Server version 5.5.2650.12">
<TITLE>RE: [sdiy] Trimming an Oakley MultiMix</TITLE>
</HEAD>
<BODY>
<P><FONT SIZE=2>> > However, for the reversible attenuator part, I want to use</FONT>
<BR><FONT SIZE=2>> > center-detent pots for a nice clean zero.</FONT>
<BR><FONT SIZE=2>></FONT>
<BR><FONT SIZE=2>> This is a simple circuit and works well for what it is. The need to trim</FONT>
<BR><FONT SIZE=2>> your centre position may be considered a little over the top for such a</FONT>
<BR><FONT SIZE=2>> circuit. After all you want complete silence from that channel you</FONT>
<BR><FONT SIZE=2>> simply pull out the jack plug. :-)</FONT>
<BR><FONT SIZE=2>----------------------------</FONT>
<BR><FONT SIZE=2>Thanks Tony, however, I'm using this in a matrix mixer configuration so I do need as best cancellation I can manage on the other busses while all jacks are in.</FONT></P>
<P><FONT SIZE=2>----------------------------</FONT>
<BR><FONT SIZE=2>> However, the way I would do would be to use say a 2K2 resistor at one</FONT>
<BR><FONT SIZE=2>> end of the pot's track, and a 4K7 trimmer at the other end. The wiper of</FONT>
<BR><FONT SIZE=2>> the pot is connected as shown on the schematic. But as John says this</FONT>
<BR><FONT SIZE=2>> circuit is not going to give you perfect cancellation at all frequencies</FONT>
<BR><FONT SIZE=2>> even when zeroed.</FONT>
<BR><FONT SIZE=2>----------------------------</FONT>
<BR><FONT SIZE=2>Thanks again sir! Maybe a way to introduce a 'dead zone' near the center? I'll do some research. </FONT>
<BR><FONT SIZE=2>KRIS</FONT>
</P>
</BODY>
</HTML>