<div dir="ltr">Unless it is precognitive, an envelope follower must have lag.<div>Of course, if you are not working live, you can play the track backwards and process that.</div><div>It is illustrative to place a piece of card over a drawing of an audio waveform, and gradually reveal more of it.</div><div>Then you can appreciate what you are asking the follower to do.</div><div>There are no perfect followers, but sometimes there are ones that are useful for a particular application.</div><div><br></div><div>paul perry melbourne australia</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">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:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">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" rel="noreferrer" 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" rel="noreferrer" 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>
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