<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=Windows-1252">
<style type="text/css" style="display:none;"> P {margin-top:0;margin-bottom:0;} </style>
</head>
<body dir="ltr">
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
I remember my brother's one from about 1972 had a meccano looking gearwheel so definitely used most of the travel. Not sure what brand it was though. I've also seen ones with lever arrangements. If you only a little part of the track it will soon wear out.<br>
</div>
<div id="appendonsend"></div>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<hr style="display: inline-block; width: 98%;">
<div dir="ltr" id="divRplyFwdMsg"><span style="font-family: Calibri, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);"><b>From:</b> Tom Wiltshire <tom@electricdruid.net><br>
<b>Sent:</b> 12 February 2024 14:12<br>
<b>To:</b> Mike Bryant <mbryant@futurehorizons.com><br>
<b>Cc:</b> SDIY List <synth-diy@synth-diy.org>; Ingo Debus <igg.debus@gmail.com><br>
<b>Subject:</b> Re: [sdiy] Cry Baby, was: Unique sounding modules that can't have voltage control?</span>
<div> </div>
</div>
<div>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>
<div><br>
</div>
<div>So yes, one does usually keep it nearer the centre - you don't get much choice.</div>
<div><br>
</div>
<blockquote>
<div>On 12 Feb 2024, at 11:05, Mike Bryant <<a href="mailto:mbryant@futurehorizons.com" id="OWAeb149798-9314-4bf8-bcc1-bd904b6f4b71" class="OWAAutoLink">mbryant@futurehorizons.com</a>> wrote:</div>
<br>
<div style="text-align: left; text-indent: 0px; 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. </div>
<div style="text-align: left; text-indent: 0px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt;">
<br>
</div>
<div style="text-align: left; text-indent: 0px; 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.</div>
<div style="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; text-decoration:none" class="" id="x_appendonsend">
</div>
<hr style="text-align: left; text-indent: 0px; display: inline-block; width: 1095.63px;">
<div style="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; text-decoration:none" class="" dir="ltr" id="x_divRplyFwdMsg">
<span style="font-family: Calibri, sans-serif; font-size: 11pt;"><b>From:</b> Synth-diy <<a href="mailto:synth-diy-bounces@synth-diy.org" id="OWA8480b24e-465f-bfd0-1746-635ceb4e3106" class="OWAAutoLink">synth-diy-bounces@synth-diy.org</a>> on behalf of Ingo
Debus via Synth-diy <<a href="mailto:synth-diy@synth-diy.org" id="OWAb5b52cd1-1064-3dbb-3fc4-0130f9b5ce2e" class="OWAAutoLink">synth-diy@synth-diy.org</a>><br>
<b>Sent:</b> 12 February 2024 08:52<br>
<b>To:</b> SDIY List <<a href="mailto:synth-diy@synth-diy.org" id="OWAcc3746b8-42b8-4b57-ee7d-aa67d5712f3f" class="OWAAutoLink">synth-diy@synth-diy.org</a>><br>
<b>Subject:</b> [sdiy] Cry Baby, was: Unique sounding modules that can't have voltage control?</span>
<div> </div>
</div>
<div style="text-align: left; text-indent: 0px; font-family: Helvetica; font-size: 12px;">
<br>
</div>
<div style="text-align: left; text-indent: 0px;"><span style="font-family: Helvetica; font-size: 12px;"><br>
</span></div>
<blockquote>
<div style="text-align: left; text-indent: 0px;"><span style="font-family: Helvetica; font-size: 12px;">Am 09.02.2024 um 21:42 schrieb Mike Bryant <<a href="mailto:mbryant@futurehorizons.com" id="OWAed03082a-59da-7cbe-bb4d-2c239e3fb132" class="OWAAutoLink">mbryant@futurehorizons.com</a>>:</span></div>
<div style="text-align: left;"><span style="font-family: Helvetica; font-size: 12px;"><br>
</span></div>
<div style="text-align: left; text-indent: 0px; 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.</div>
<div class="" id="x_x_appendonsend"></div>
<hr style="text-align: left; text-indent: 0px; display: inline-block; width: 1106.41px;">
<div class="" dir="ltr" id="x_x_divRplyFwdMsg"><span style="font-family: Calibri, sans-serif; font-size: 11pt;"><b>From:</b> Synth-diy <<a href="mailto:synth-diy-bounces@synth-diy.org" id="OWAd6389e76-c825-3b9c-3acd-e07b0b25f9f9" class="OWAAutoLink">synth-diy-bounces@synth-diy.org</a>>
on behalf of Ingo Debus via Synth-diy <<a href="mailto:synth-diy@synth-diy.org" id="OWA017ba559-4d7f-293f-1de9-0dc7ddfeffa2" class="OWAAutoLink">synth-diy@synth-diy.org</a>><br>
<b>Sent:</b> 09 February 2024 20:28<br>
<b>To:</b> SDIY List <<a href="mailto:synth-diy@synth-diy.org" id="OWA9ee68295-487a-0931-9b4e-2cba4661ff10" class="OWAAutoLink">synth-diy@synth-diy.org</a>><br>
<b>Subject:</b> Re: [sdiy] Unique sounding modules that can't have voltage control?</span>
<div> </div>
</div>
</blockquote>
<div style="text-align: left;"><span style="font-family: Helvetica; font-size: 12px;">[…]<br>
</span></div>
<blockquote>
<div style="text-align: left; text-indent: 0px;"><span style="font-family: Helvetica; font-size: 12px;">Looking at this description of the Cry Baby:</span></div>
<div style="text-align: left; text-indent: 0px;"><span style="font-family: Helvetica; font-size: 12px;"><a href="https://www.electrosmash.com/crybaby-gcb-95" data-auth="NotApplicable" id="OWAae62dc2e-b0fa-e515-37f7-8150c97880a1" class="OWAAutoLink">https://www.electrosmash.com/crybaby-gcb-95</a></span></div>
<div style="text-align: left; text-indent: 0px;"><span style="font-family: Helvetica; font-size: 12px;"><br>
</span></div>
<div style="text-align: left; text-indent: 0px;"><span style="font-family: Helvetica; font-size: 12px;">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?</span></div>
<div style="text-align: left;"><span style="font-family: Helvetica; font-size: 12px;"><br>
</span></div>
</blockquote>
<div style="text-align: left;"><span style="font-family: Helvetica; font-size: 12px;"><br>
</span></div>
<div style="text-align: left; text-indent: 0px;"><span style="font-family: Helvetica; font-size: 12px;">So I downloaded the LTSpice model of the Cry Baby here:</span></div>
<div style="text-align: left; text-indent: 0px;"><span style="font-family: Helvetica; font-size: 12px;"><a href="https://cushychicken.github.io/ltspice-dunlop-crybaby/" data-auth="NotApplicable" id="OWAb82721f5-ac00-d044-f89e-18050c32e524" class="OWAAutoLink">https://cushychicken.github.io/ltspice-dunlop-crybaby/</a></span></div>
<div style="text-align: left; text-indent: 0px;"><span style="font-family: Helvetica; font-size: 12px;"><br>
</span></div>
<div style="text-align: left; text-indent: 0px;"><span style="font-family: Helvetica; font-size: 12px;">Here’s the frequency plot for various positions of the potentiometer:</span></div>
<div style="text-align: left; text-indent: 0px;"><span style="font-family: Helvetica; font-size: 12px;"><Bildschirmfoto 2024-02-11 um 20.53.37.png></span></div>
<div style="text-align: left; text-indent: 0px;"><span style="font-family: Helvetica; font-size: 12px;"><br>
</span></div>
<div style="text-align: left; text-indent: 0px;"><span style="font-family: Helvetica; font-size: 12px;">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:</span></div>
<div style="text-align: left; text-indent: 0px;"><span style="font-family: Helvetica; font-size: 12px;"><Bildschirmfoto 2024-02-11 um 20.52.03.png></span></div>
<div style="text-align: left; text-indent: 0px;"><span style="font-family: Helvetica; font-size: 12px;"><br>
</span></div>
<div style="text-align: left; text-indent: 0px;"><span style="font-family: Helvetica; font-size: 12px;">Almost the same as the real thing. The peaks at the low frequencies are slightly higher.</span></div>
<div style="text-align: left; text-indent: 0px;"><span style="font-family: Helvetica; font-size: 12px;">So my conclusion is, the pot in the Cry Baby can be replaced by a VCA without altering the performance very much.</span></div>
<div style="text-align: left; text-indent: 0px;"><span style="font-family: Helvetica; font-size: 12px;"><br>
</span></div>
<div style="text-align: left; text-indent: 0px;"><span style="font-family: Helvetica; font-size: 12px;">Ingo</span></div>
<span style="font-family: Helvetica; font-size: 12px;">________________________________________________________</span><br>
<span style="font-family: Helvetica; font-size: 12px;">This is the Synth-diy mailing list</span><br>
<span style="font-family: Helvetica; font-size: 12px;">Submit email to: <a href="mailto:Synth-diy@synth-diy.org" id="OWA330737aa-e082-8ef6-a49a-3fefcededbb4" class="OWAAutoLink">
Synth-diy@synth-diy.org</a></span><br>
<span style="font-family: Helvetica; font-size: 12px;">View archive at: <a href="https://synth-diy.org/pipermail/synth-diy/" data-auth="NotApplicable" id="OWAd9c0c83a-de18-46bc-b114-1e907430925b" class="OWAAutoLink">
https://synth-diy.org/pipermail/synth-diy/</a></span><br>
<span style="font-family: Helvetica; font-size: 12px;">Check your settings at: <a href="https://synth-diy.org/mailman/listinfo/synth-diy" data-auth="NotApplicable" id="OWA17e07535-349c-2dd1-9f2c-8501c036fcc2" class="OWAAutoLink">
https://synth-diy.org/mailman/listinfo/synth-diy</a></span><br>
<span style="font-family: Helvetica; font-size: 12px;">Selling or trading? Use <a href="mailto:marketplace@synth-diy.org" id="OWA7a761d17-5ac2-133a-9d1d-d8a6082d5f87" class="OWAAutoLink">
marketplace@synth-diy.org</a></span></blockquote>
<br>
</body>
</html>