<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="">I see a lot of +/-12V bipolar power supplies used in those schematics. All the SSM2056/SSM2044 stuff, and the surrounding op-amps, for example. The only part that seems to be single supply is the LM3094. Is that a version of the CA3094 OTA?<div class=""><div class=""><div><br class=""></div>
</div>
<div><br class=""><blockquote type="cite" class=""><div class="">On 5 Mar 2024, at 23:36, hannes.janetzek--- via Synth-diy <<a href="mailto:synth-diy@synth-diy.org" class="">synth-diy@synth-diy.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class="">Hello - now that I have your attention I would like to bring up the sad topic of the numerous synthesizers covering in 80s home-organs that are daily thrown in the trash by their inheritors.<div class="">Ok maybe this is a specific southern Germany problem where it appears every second home had a Hohner organ which outlived their role as status symbol by now.. In the US these model were sold as Wurlitzer Omni 3000-6500 - not sure if these are regularly in classified for pickup as well.</div><div class=""><br class=""></div><div class="">My interest in these devices is mainly in their MEG sound-generator for which I'm currently writing an interface library. As this starts to work out nicely I wanted to throw in the filter boards and was very surprised to see that all the VCAs and most of the mixing is powered with ground to 12V. </div><div class="">Has anyone an idea what could be the reasoning or advantage of this approach? (I'm very much a beginner on the analog electronics side) </div><div class="">The schematic is on page 35 and all boards I've seen use the BA6110 version:<br class=""></div><div class=""><a href="https://www.synthxl.com/wp-content/uploads/2020/08/Hohner-Symphonie-D98-Service-Manual.pdf" class="">https://www.synthxl.com/wp-content/uploads/2020/08/Hohner-Symphonie-D98-Service-Manual.pdf</a><br class=""></div><div class="">Page 24-29 for the sound-generator - if you are curious. <br class=""></div><div class=""><br class=""></div><div class="">Regards</div><div class="">Hannes</div></div>
________________________________________________________<br class="">This is the Synth-diy mailing list<br class="">Submit email to: <a href="mailto:Synth-diy@synth-diy.org" class="">Synth-diy@synth-diy.org</a><br class="">View archive at: <a href="https://synth-diy.org/pipermail/synth-diy/" class="">https://synth-diy.org/pipermail/synth-diy/</a><br 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><br class="">Selling or trading? Use <a href="mailto:marketplace@synth-diy.org" class="">marketplace@synth-diy.org</a><br class=""></div></blockquote></div><br class=""></div></body></html>