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</o:shapelayout></xml><![endif]--></head><body lang=FR-CA link=blue vlink=purple style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'>Precognitive… Interesting.<br>This can be done easily with a PIC reading a moving input voltage<br>then output the computed results on its DAC for example a bit later<br>according to where the actual incoming waveform is heading (plus or minus). <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='mso-fareast-language:EN-US'><o:p> </o:p></span></p><div style='border:none;border-left:solid blue 1.5pt;padding:0cm 0cm 0cm 4.0pt'><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=FR>De :</span></b><span lang=FR> Paul Perry <paulfrancisperry@gmail.com> <br><b>Envoyé :</b> 15 décembre 2021 16:44<br><b>À :</b> Benjamin Tremblay <btremblay@me.com><br><b>Cc :</b> Jean-Pierre Desrochers <jpdesroc@oricom.ca>; Synth-diy@synth-diy.org<br><b>Objet :</b> Re: [sdiy] Best & fastest envelope follower schematic.. anybody ?<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>Unless it is precognitive, an envelope follower must have lag.<o:p></o:p></p><div><p class=MsoNormal>Of course, if you are not working live, you can play the track backwards and process that.<o:p></o:p></p></div><div><p class=MsoNormal>It is illustrative to place a piece of card over a drawing of an audio waveform, and gradually reveal more of it.<o:p></o:p></p></div><div><p class=MsoNormal>Then you can appreciate what you are asking the follower to do.<o:p></o:p></p></div><div><p class=MsoNormal>There are no perfect followers, but sometimes there are ones that are useful for a particular application.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>paul perry melbourne australia<o:p></o:p></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>On Thu, 16 Dec 2021 at 02:35, Benjamin Tremblay via Synth-diy <<a href="mailto:synth-diy@synth-diy.org">synth-diy@synth-diy.org</a>> wrote:<o:p></o:p></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm'><p class=MsoNormal>I lost all interest in envelope followers when I tried out some designs and observed the lag. <br>These are mostly “envelope smoothers” and most are barely any better than an old incandescent vactrol attenuator circuit used in FM broadcast.<br>They mostly just drive non-musical effects under the category “something weird happens when I play my guitar”. Pre-filtering the audio probably helps but there’s no guidance on best all-round EQ.<br>Only The Residents got much mileage out of envelope followers over the years.<br><br>> On Dec 15, 2021, at 10:05 AM, Jean-Pierre Desrochers <<a href="mailto:jpdesroc@oricom.ca" target="_blank">jpdesroc@oricom.ca</a>> wrote:<br>> <br>> Hi Tom,<br>> <br>>> Harry Bissell's envelope follower is well thought of for its combination of speed and accuracy.<br>>> <a href="https://modwiggler.com/forum/viewtopic.php?t=109067" target="_blank">https://modwiggler.com/forum/viewtopic.php?t=109067</a><br>> <br>> This is a very clever project and neat design.<br>> But still too much ‘lag’ on the falling edges incoming signal.<br>> So far.. a PIC would do best with least components..<br>> Hmmmm...<br>> As usual.. Thank you for you good suggestion anyway !<br>> JP<br>> <br>> <br>> De : Tom Wiltshire <<a href="mailto:tom@electricdruid.net" target="_blank">tom@electricdruid.net</a>> <br>> Envoyé : 15 décembre 2021 04:08<br>> À : Jean-Pierre Desrochers <<a href="mailto:jpdesroc@oricom.ca" target="_blank">jpdesroc@oricom.ca</a>><br>> Cc : <a href="mailto:Synth-diy@synth-diy.org" target="_blank">Synth-diy@synth-diy.org</a><br>> Objet : Re: [sdiy] Best & fastest envelope follower schematic.. anybody ?<br>> <br>> Hi JP,<br>> <br>> Harry Bissell's envelope follower is well thought of for its combination of speed and accuracy.<br>> <br>> <a href="https://modwiggler.com/forum/viewtopic.php?t=109067" target="_blank">https://modwiggler.com/forum/viewtopic.php?t=109067</a><br>> <br>> It's a good circuit, but pretty complicated, especially for an effect pedal design. So like you, I thought "PIC!", and had a go at implementing it in firmware.<br>> <br>> The round-robin three peaks detectors are easy enough. Doing the output filtering is more demanding on a chip with no multiply, but I managed it by being choosy about the filter coefficients and keeping things binary friendly. The end result was pretty good and used a little PIC to the maximum extent.<br>> <br>> HTH,<br>> Tom<br>> <br>> ==================<br>> Electric Druid<br>> Synth & Stompbox DIY<br>> ==================<br>> <br>> <br>> <br>> <br>> On 15 Dec 2021, at 01:34, Jean-Pierre Desrochers <mailto:<a href="mailto:jpdesroc@oricom.ca" target="_blank">jpdesroc@oricom.ca</a>> wrote:<br>> <br>> Hi all,<br>> I’m looking for a fast and accurate voltage follower circuit.<br>> There are plenty of them on the web to build but they all<br>> suffer of inaccuracy and lag on the final DC output (final stage of low pass to smooth off the incoming peaks).<br>> The incoming voltage will be a varying 0 to +/-5v peak.<br>> I thought about implementing a solution using a small PIC with ADC/DAC<br>> but even if these micros are very cheap this solution would be overkill.. would it be ?<br>> So far the available circuits have too much lag on their DC output.<br>> (The envelope takes too much time to get back to zero after a fast incoming peak)<br>> Any known & reliable circuits ?<br>> JP<br>> _______________________________________________<br>> Synth-diy mailing list<br>> mailto:<a href="mailto:Synth-diy@synth-diy.org" target="_blank">Synth-diy@synth-diy.org</a><br>> <a href="http://synth-diy.org/mailman/listinfo/synth-diy" target="_blank">http://synth-diy.org/mailman/listinfo/synth-diy</a><br>> Selling or trading? Use mailto:<a href="mailto:marketplace@synth-diy.org" target="_blank">marketplace@synth-diy.org</a><br>> <br>> <br>> <br>> _______________________________________________<br>> Synth-diy mailing list<br>> <a href="mailto:Synth-diy@synth-diy.org" target="_blank">Synth-diy@synth-diy.org</a><br>> <a href="http://synth-diy.org/mailman/listinfo/synth-diy" target="_blank">http://synth-diy.org/mailman/listinfo/synth-diy</a><br>> Selling or trading? Use <a href="mailto:marketplace@synth-diy.org" target="_blank">marketplace@synth-diy.org</a><br><br><br>_______________________________________________<br>Synth-diy mailing list<br><a href="mailto:Synth-diy@synth-diy.org" target="_blank">Synth-diy@synth-diy.org</a><br><a href="http://synth-diy.org/mailman/listinfo/synth-diy" target="_blank">http://synth-diy.org/mailman/listinfo/synth-diy</a><br>Selling or trading? Use <a href="mailto:marketplace@synth-diy.org" target="_blank">marketplace@synth-diy.org</a><o:p></o:p></p></blockquote></div></div></div></body></html>