<html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div class=""><div>I think he's got a point. How many filter topologies are there that are analog, audio range, and accurately voltage controlled over a substantial range? I count two.</div><div><br class=""></div><div>The Diode Ladder is essentially derivative of the Moog, even though it works differently. </div><div><br class=""></div><div>There are VCFs based on the Sallen-Key, or any other active filter topology, hacked up for voltage control, sure. Though they have less precise tuning.</div><div><br class=""></div><div>In practice, don't the Moog Ladder and the State Variable account for 95% or more of the filters used in synths? What am I missing?</div><div><br class=""></div><div>I have several filter topologies of my own, of course, so I'm not saying there are inherent limitations or anything.</div><div><br class=""></div><div> -- Don<br class="">--<br class="">Donald Tillman, Palo Alto, California<br class=""><a href="http://www.till.com" class="">http://www.till.com</a></div><div class=""><br class=""></div></div><div><br class=""><blockquote type="cite" class=""><div class="">On Aug 22, 2019, at 12:52 PM, Kylee Kennedy <<a href="mailto:kmkennedy@gmail.com" class="">kmkennedy@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class="">Honestly it was hard to get past "Learn about one of the only audio filter topologies out there, the Moog filter!"<div class=""><br class=""></div><div class="">Kylee<br class=""><div class=""><br class=""></div></div></div><br class=""><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Aug 22, 2019 at 12:33 PM Ian Fritz <<a href="mailto:ijfritz@comcast.net" class="">ijfritz@comcast.net</a>> wrote:<br class=""></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Not many synth filters? That could make many people unhappy. Oh well <br class="">
it's just a kid.<br class="">
<br class="">
Ian<br class="">
<br class="">
On 8/22/2019 12:51 PM, Ingo Debus wrote:<br class="">
> Anyone seen this?<br class="">
> <a href="https://www.allaboutcircuits.com/technical-articles/analyzing-the-moog-filter/" rel="noreferrer" target="_blank" class="">https://www.allaboutcircuits.com/technical-articles/analyzing-the-moog-filter/</a><br class="">
> <a href="https://www.allaboutcircuits.com/technical-articles/small-signal-open-loop-transfer-function-moog-filter/" rel="noreferrer" target="_blank" class="">https://www.allaboutcircuits.com/technical-articles/small-signal-open-loop-transfer-function-moog-filter/</a><br class="">
> <br class="">
> Ingo</blockquote></div></div></blockquote></div></body></html>