<html><body style="font-family: Helvetica,Arial,sans-serif; font-size: 12px;">You can construct fixed lower octave PWM signals to some degree, by ORing the signals from multiple octaves above.<br><br>f0=10101010 OR f1=11001100 => f2=11101110 (ie. f2 two octaves below f0, with a 3:1 PWM ratio)<br><br>Similarly AND gives you a 1:3 PWM ratio.<br><br>Obviously your pitch width options are quite limited using this approach and it's not really what you were looking for. But it might be interesting nevertheless :) I'm pretty sure I've seen this technique used in a vintage organ circuit somewhere. I'm equally sure it would require a whole bunch of extra circuitry....<br><br>Cheers,<br>A.<br><br><blockquote class="atmailquote"><br>----- Original Message -----<br><div id="origionalMessageFromField" style="width:100%;display:inline;background:rgb(228,228,228);"><div style="display:inline;font-weight:bold;">From:</div> "Dave Garfield" <daveogarf@yahoo.com></div><br><div id="origionalMessageToField" style="display:inline;font-weight:bold;">To:</div>"Tom Wiltshire" <tom@electricdruid.net>, "Mike HEQX" <mike@heqx.com><br><div id="origionalMessageSentField" style="display:inline;font-weight:bold;">Cc:</div>"Synth DIY" <synth-diy@synth-diy.org><br><div style="display:inline;font-weight:bold;">Sent:</div>Tue, 19 Sep 2017 23:49:10 +0000 (UTC)<br><div id="origionalMessageSubjectField" style="display:inline;font-weight:bold;">Subject:</div>Re: [sdiy] pwming a tog<br><br><br><div style="color:#000;background-color:#fff;font-family:verdana, helvetica, sans-serif;font-size:16px;"><div id="yui_3_16_0_ym19_1_1505862289768_38119">Hi, all</div><div id="yui_3_16_0_ym19_1_1505862289768_38899" dir="ltr">While it doesn't do PWM, an English company named FlatKeys produces a Top Octave Generator replacement for the classic synths and organs which use a 50240 TOG. This one isn't just a divider; it generates 12 separate top octave waves which are in tune, unlike the originals' approximations.<br>It will also do vibrato, as it has a master clock. It can switch octaves if desired, or transpose keys. <br>The price is £52.80.<br>I haven't tried one out, but have been meaning to for a long time. If anyone else out there has, I'd love to hear about it - warts and all. Maybe it will work for you, or someone else out there.</div><div id="yui_3_16_0_ym19_1_1505862289768_38872" dir="ltr"><a class="enhancr2_25de5670-1564-a9fb-8d18-3b2c135ea869 edited-link-editor" id="yui_3_16_0_ym19_1_1505862289768_38871" href="http://www.flatkeys.co.uk/MK50240.html">FK50240 MK50240</a> </div><div id="yui_3_16_0_ym19_1_1505862289768_39147" dir="ltr">I am NOT affiliated with FlatKeys in any way, shape, form or manner. Just thought that this might be a good solution for replacing scarce top octave divider chips.</div><div id="yui_3_16_0_ym19_1_1505862289768_38898"><br></div><div class="yahoo-link-enhancr-card yahoo-link-enhancr-not-allow-cover ymail-preserve-class ymail-preserve-style" id="enhancr2_25de5670-1564-a9fb-8d18-3b2c135ea869" style="font-family:'Helvetica Neue', Helvetica, Arial, sans-serif;" dir="ltr"> <a class="yahoo-enhancr-cardlink" id="yui_3_16_0_ym19_1_1505862289768_38888" style="text-decoration:none;color:#000;" href="http://www.flatkeys.co.uk/MK50240.html"> </a><table class="card-wrapper" id="yui_3_16_0_ym19_1_1505862289768_38887" cellspacing="0" cellpadding="0" border="0"><tbody id="yui_3_16_0_ym19_1_1505862289768_38886"><tr id="yui_3_16_0_ym19_1_1505862289768_38885"><td id="yui_3_16_0_ym19_1_1505862289768_38884" style="width:400px;"> <table class="card-info" id="yui_3_16_0_ym19_1_1505862289768_38883" style="background:#fff;border:1px solid #e0e4e9;border-bottom:3px solid #000000;" width="100%" cellspacing="0" cellpadding="0" border="0"><tbody id="yui_3_16_0_ym19_1_1505862289768_38882"><tr id="yui_3_16_0_ym19_1_1505862289768_38881"><td style="vertical-align:top;padding:16px 0 16px 12px;"> </td> <td id="yui_3_16_0_ym19_1_1505862289768_38880" style="vertical-align:middle;padding:16px 12px;width:99%;"> <h2 class="card-title" style="margin:0 0 4px 0;font-size:16px;font-family:'Helvetica Neue', Helvetica, Arial, sans-serif;">FK50240 MK50240</h2> <div class="card-description" style="font-size:11px;line-height:15px;color:#999;"></div> </td> <td class="card-share-container"></td> </tr></tbody></table></td> </tr></tbody></table></div><div id="yui_3_16_0_ym19_1_1505862289768_39151"><br></div> <div class="qtdSeparateBR"><br><br></div><div class="yahoo_quoted" style="display:block;"> <div style="font-family:verdana, helvetica, sans-serif;font-size:16px;"> <div style="font-family:HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif;font-size:16px;"> <div dir="ltr"><span style="font-family:Arial;font-size:small;"> On Tuesday, September 19, 2017 5:32 PM, Tom Wiltshire <tom@electricdruid.net> wrote:<br></span></div> <br><br><div class="y_msg_container"><div dir="ltr">Because the standard TOG is based on dividers, you can’t add PWM. Run any width pulse wave through a flip-flop and the output's a square, after all.<br style="clear:none;"><br style="clear:none;">That said, there were some TOGs the produced 33% pulse waves rather than squares (not sure exactly what the internals were to do that) but there were none that offered PWM.<br style="clear:none;"><br style="clear:none;">If you had twelve ramp oscillators for the top-octave, you could arrange ramp+squares to give you ramps at various divided octaves, and then use those ramps to produce PWM, but it’d be a lot of circuitry, and it’d probably get a bit sensitive. Have a search for “sub-octave ramp wave” to get the basic idea.<br style="clear:none;"><br style="clear:none;">HTH,<br style="clear:none;">Tom<br style="clear:none;"><br style="clear:none;">==================<br style="clear:none;"> Electric Druid<br style="clear:none;">Synth & Stompbox DIY<br style="clear:none;">==================<br style="clear:none;"><br style="clear:none;">> On 20 Sep 2017, at 00:06, Mike HEQX <<a href="mailto:mike@heqx.com">mike@heqx.com</a>> wrote:<br style="clear:none;">> <br style="clear:none;">> I wanted to do something with a TOG and I was hoping I could add PWM to it. Not sure if you can PWM the master clock though, but that's what I want to try. After all you pitch bend it that way.<br style="clear:none;">> <br style="clear:none;">> I not does that mean 12 pwm on the output of the tog?<br style="clear:none;">> <br style="clear:none;">> <br style="clear:none;">> thoughts?<br style="clear:none;">> <br style="clear:none;">> <br style="clear:none;">> Mike<br style="clear:none;">> <br style="clear:none;">> _______________________________________________<br style="clear:none;">> Synth-diy mailing list<br style="clear:none;">> <a href="mailto:Synth-diy@synth-diy.org">Synth-diy@synth-diy.org</a><br style="clear:none;">> <a href="http://synth-diy.org/mailman/listinfo/synth-diy">http://synth-diy.org/mailman/listinfo/synth-diy</a><div class="yqt8406813847" id="yqtfd10797"><br style="clear:none;"><br style="clear:none;"><br style="clear:none;">_______________________________________________<br style="clear:none;">Synth-diy mailing list<br style="clear:none;"><a href="mailto:Synth-diy@synth-diy.org">Synth-diy@synth-diy.org</a><br style="clear:none;"><a href="http://synth-diy.org/mailman/listinfo/synth-diy">http://synth-diy.org/mailman/listinfo/synth-diy</a><br style="clear:none;"></div></div><br><br></div> </div> </div> </div></div>
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