<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">A typical wah pot can't physically reach the ends of its travel, so the simulation probably goes further at both ends than the reality.<div class=""><br class=""></div><div class="">So yes, one does usually keep it nearer the centre - you don't get much choice.<br class="">
<div><br class=""><blockquote type="cite" class=""><div class="">On 12 Feb 2024, at 11:05, Mike Bryant <<a href="mailto:mbryant@futurehorizons.com" class="">mbryant@futurehorizons.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="elementToProof" style="font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt;">That's fine then if the VCA also moves the frequency as you've proven. <span class="Apple-converted-space"> </span><br class=""></div><div class="elementToProof" style="font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt;"><br class=""></div><div class="elementToProof" style="font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt;">Quite amazed at how much the pot, or VCA, moves the resonant frequency - I suppose one usually keeps it nearer the centre.<br class=""></div><div id="appendonsend" style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""></div><hr tabindex="-1" style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; display: inline-block; width: 1095.625px;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class=""></span><div id="divRplyFwdMsg" dir="ltr" style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><font face="Calibri, sans-serif" style="font-size: 11pt;" class=""><b class="">From:</b><span class="Apple-converted-space"> </span>Synth-diy <<a href="mailto:synth-diy-bounces@synth-diy.org" class="">synth-diy-bounces@synth-diy.org</a>> on behalf of Ingo Debus via Synth-diy <<a href="mailto:synth-diy@synth-diy.org" class="">synth-diy@synth-diy.org</a>><br class=""><b class="">Sent:</b><span class="Apple-converted-space"> </span>12 February 2024 08:52<br class=""><b class="">To:</b><span class="Apple-converted-space"> </span>SDIY List <<a href="mailto:synth-diy@synth-diy.org" class="">synth-diy@synth-diy.org</a>><br class=""><b class="">Subject:</b><span class="Apple-converted-space"> </span>[sdiy] Cry Baby, was: Unique sounding modules that can't have voltage control?</font><div class=""> </div></div><div class="" style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; word-wrap: break-word;"><br class=""><div class=""><div class=""><br class=""><blockquote type="cite" class=""><div class="">Am 09.02.2024 um 21:42 schrieb Mike Bryant <<a href="mailto:mbryant@futurehorizons.com" class="">mbryant@futurehorizons.com</a>>:</div><br class="x_Apple-interchange-newline"><div class=""><div class="x_elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt;">R5 C4 VR1 also form a variable frequency element as well as controlling the feedback level. Hence the waa effect.<br class=""></div><div id="x_appendonsend" class=""></div><hr tabindex="-1" class="" style="display: inline-block; width: 1106.40625px;"><div id="x_divRplyFwdMsg" dir="ltr" class=""><font face="Calibri, sans-serif" class="" style="font-size: 11pt;"><b class="">From:</b> Synth-diy <<a href="mailto:synth-diy-bounces@synth-diy.org" class="">synth-diy-bounces@synth-diy.org</a>> on behalf of Ingo Debus via Synth-diy <<a href="mailto:synth-diy@synth-diy.org" class="">synth-diy@synth-diy.org</a>><br class=""><b class="">Sent:</b> 09 February 2024 20:28<br class=""><b class="">To:</b> SDIY List <<a href="mailto:synth-diy@synth-diy.org" class="">synth-diy@synth-diy.org</a>><br class=""><b class="">Subject:</b> Re: [sdiy] Unique sounding modules that can't have voltage control?</font><div class=""> </div></div><div class="" style="word-wrap: break-word; line-break: after-white-space;"></div></div></blockquote>[…]<br class=""><blockquote type="cite" class=""><div class=""><div class="" style="word-wrap: break-word; line-break: after-white-space;"><div class="">Looking at this description of the Cry Baby:</div><div class=""><a href="https://www.electrosmash.com/crybaby-gcb-95" class="">https://www.electrosmash.com/crybaby-gcb-95</a></div><div class=""><br class=""></div><div class="">It seems to me that the pot just sets the amount of feedback. This could be easily replaced by a VCA. Am I missing something?</div></div><br class="x_Apple-interchange-newline"></div></blockquote></div><br class=""><div class="">So I downloaded the LTSpice model of the Cry Baby here:</div><div class=""><a href="https://cushychicken.github.io/ltspice-dunlop-crybaby/" class="">https://cushychicken.github.io/ltspice-dunlop-crybaby/</a></div><div class=""><br class=""></div><div class="">Here’s the frequency plot for various positions of the potentiometer:</div><div class=""><span id="cid:ACFF5095-0F86-474D-9117-36E1831AD156"><Bildschirmfoto 2024-02-11 um 20.53.37.png></span></div><div class=""><br class=""></div><div class="">Then I replaced the potentiometer R14/R12 with a „voltage controlled voltage source“, emulating an ideal VCA. The gain was set to the same values the (unloaded) potentiometer would yield. Here’s the result:</div><div class=""><span id="cid:F7EB41B7-E3E9-4204-B6C2-959EAAB9C87B"><Bildschirmfoto 2024-02-11 um 20.52.03.png></span></div><div class=""><br class=""></div><div class="">Almost the same as the real thing. The peaks at the low frequencies are slightly higher.</div><div class="">So my conclusion is, the pot in the Cry Baby can be replaced by a VCA without altering the performance very much.</div><div class=""><br class=""></div><div class="">Ingo</div></div></div><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">________________________________________________________</span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">This is the Synth-diy mailing list</span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">Submit email to: <a href="mailto:Synth-diy@synth-diy.org" class="">Synth-diy@synth-diy.org</a></span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">View archive at: <a href="https://synth-diy.org/pipermail/synth-diy/" class="">https://synth-diy.org/pipermail/synth-diy/</a></span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">Check your settings at: <a href="https://synth-diy.org/mailman/listinfo/synth-diy" class="">https://synth-diy.org/mailman/listinfo/synth-diy</a></span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">Selling or trading? 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