<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="">Yes, Alfa make a clone - or at least a chip with that number:<div class=""><br class=""></div><div class=""><a href="https://www.alfarzpp.lv/eng/sc/AS662D.pdf" class="">https://www.alfarzpp.lv/eng/sc/AS662D.pdf</a></div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">
<div><br class=""><blockquote type="cite" class=""><div class="">On 19 Jun 2023, at 04:41, Adam (synthDIY) <<a href="mailto:synthdiy@adambaby.com" class="">synthdiy@adambaby.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="">Actually, yes you're right, the Roland BA662 OTA that they used a lot around this time, both for VCAs and VCFs. I've sent you the schematic.<br class=""><br class="">I think they've been cloned successfully in recent years<br class=""><br class="">A<br class=""><br class=""><blockquote type="cite" class="">On 19 Jun 2023, at 1:10 pm, brianw <<a href="mailto:brianw@audiobanshee.com" class="">brianw@audiobanshee.com</a>> wrote:<br class=""><br class="">Although the VCO is surely bespoke, I was thinking that the VCF and/or VCA might be one of those dedicated chips that perform individual functions. Do you have a link to the schematic? I'd be curious to see how the VCF and VCA are implemented.<br class=""><br class="">Brian<br class=""><br class=""><br class="">On Jun 17, 2023, at 8:54 PM, Adam wrote:<br class=""><blockquote type="cite" class="">I don't think there's any "vintage synth chips" in this, is there? It's basically a pitch to CV converter driving a VCO/VCF/VCA with envelope control, same era as the SH-09 monosynth.<br class=""><br class="">Actually just looking at the schem now, I'd always assumed they used a Phase Locked Loop in there but I can't see one.<br class=""><br class="">One thing I do see in there that is virtually unobtainium is a Fairchild uA726, IC18<br class=""><br class=""><grab 2023-06-18 at 1.52.50 pm.png><br class=""><br class=""><br class=""><br class="">Unless someone has managed to clone that in recent years..?<br class=""><br class="">A<br class=""></blockquote><br class=""></blockquote><br class=""><br class="">_______________________________________________<br class="">Synth-diy mailing list<br class=""><a href="mailto:Synth-diy@synth-diy.org" class="">Synth-diy@synth-diy.org</a><br class="">http://synth-diy.org/mailman/listinfo/synth-diy<br class="">Selling or trading? Use marketplace@synth-diy.org<br class=""></div></div></blockquote></div><br class=""></div></body></html>