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<TITLE>Weird Osc sync (Was Re: triggered s&h, in phasers or modules?)</TITLE>
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<P><FONT SIZE=2>-----Original Message-----</FONT>
<BR><FONT SIZE=2>From: Robert H. Rickner-III [<A HREF="mailto:rrickner@zoo.uvm.edu">mailto:rrickner@zoo.uvm.edu</A>]</FONT>
<BR><FONT SIZE=2>Sent: 27 January 2000 16:40</FONT>
<BR><FONT SIZE=2>To: synth-diy@mailhost.bpa.nl</FONT>
<BR><FONT SIZE=2>Subject: Re: Re: triggered s&h, in phasers or modules?</FONT>
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<P><FONT SIZE=2>On Wed, 26 Jan 2000 WeAreAs1@aol.com wrote:</FONT>
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<P><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> In a message dated 1/26/00 7:17:44 PM, you wrote:</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> <<Will this work with any LFO, ie could I add a trigger input to one LFO and</FONT>
<BR><FONT SIZE=2>> run in a S&H for wacky LFO possibilities? >></FONT>
<BR><FONT SIZE=2>>> </FONT>
<BR><FONT SIZE=2>>> It will work with most LFO circuits, especially the typical one found in most </FONT>
<BR><FONT SIZE=2>>> synths (two opamp stages: triangle integrator followed by comparator with </FONT>
<BR><FONT SIZE=2>>> squarewave output). What synth would you like to modify to have a syncable </FONT>
<BR><FONT SIZE=2>>> LFO?</FONT>
<BR><FONT SIZE=2>></FONT>
<BR><FONT SIZE=2>> Well, I'm trying to build a modular synth and am collecting scematics from</FONT>
<BR><FONT SIZE=2>> the web to choose the initial modules, mostly from the efm related</FONT>
<BR><FONT SIZE=2>> pages. So, I'd like a whole bunch of functions more than just another</FONT>
<BR><FONT SIZE=2>> analogue synth, I have a Matrix 6 for that, so I'm interested in any</FONT>
<BR><FONT SIZE=2>> modifications and modules that aren't available normally. I don't want</FONT>
<BR><FONT SIZE=2>> the syncable lfo as much as I want the weird effects when you choose a</FONT>
<BR><FONT SIZE=2>> trigger time different from the lfo.</FONT>
<BR><FONT SIZE=2>> Rob cut/generic</FONT>
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<P><FONT SIZE=2>I bought a burned-out EMS Synthi A, a long time ago, and rebuilt it into a 6 Osc duophonic beast, and with the help of a friend who was an EMS techie, added a whole bunch of unusual features. To me the most intriging was a form of oscillator sync I haven't come across since. </FONT></P>
<P><FONT SIZE=2>If I remember correctly, if you were listening to VCO2 which was synced to VCO 1 (level=0), as you attempted to vary the freq of VCO2, the actual frequency wouldn't change, but you'd hear the familiar soft sync sound. As you continued to move VCO2 further away from VCO1, the frequency would jump to next pythagorean harmonic. So if you frequency modulated VCO2 with (say) a 0.2Hz triangle, you'd hear a musically pleasing appeggio with an unusual character since the soft sync would start again after each 'jump'.</FONT></P>
<P><FONT SIZE=2>I've heard it a few times in popular music, but the only one I can bring to mind is on Joan Baez's 'Diamonds and Rust'.</FONT>
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<P><FONT SIZE=2>This was a simple mod to the EMS VCO. I'm not sure how it would be achieved on modern VCO designs, but if it's possible it could probably be done for minimal cost.</FONT></P>
<P><FONT SIZE=2>To Rob, I'd say if you you can find out how to do this, you should seriously consider adding this feature. If anyone knows how to do it, please let me know!</FONT></P>
<P><FONT SIZE=2>Rod</FONT>
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