<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto">Switch mode power supplies are far more efficient (80%) than simply using an LDO and they can be as clean as linear power supplies. Besides the conversion efficiency upgrade that reduces heat, depending on your switching frequency, you can really shrink down the size of the passives required. If you push the switching frequency far enough out of the audible band, all you have to do is clean up some easy harmonics. <div><div>On the schematic side, proper inductor and capacitor selection can minimize the capacitor discharge that causes the ripple. <div>More importantly, proper layout can make or break a switcher. Proper care should be given to the feedback node and it’s loop to minimize noise. </div><div>Synths are relatively big so you shouldn’t have to make many (any) sacrifices in proper part placement and routing. </div><div>Simulations are incredibly helpful for the schematic part of the design and anticipating ripple. If you can get your hands on simulation software like PowerSI, you can really hone in your design.</div><div><div dir="ltr"><br><div>Oren Levy</div></div><div dir="ltr"><br><blockquote type="cite">On Oct 30, 2019, at 20:46, Adam Inglis <21pointy@tpg.com.au> wrote:<br><br></blockquote></div><blockquote type="cite"><div dir="ltr"><meta http-equiv="Content-Type" content="text/html charset=utf-8"><br class=""><div><blockquote type="cite" class=""><div class="">On 31 Oct 2019, at 1:17 PM, Quincas Moreira <<a href="mailto:quincas@gmail.com" class="">quincas@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><span style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">I don’t exactly know, but I think its switchmode DCDC converter from the 12v dc walwart to 15v bipolar, then gets filtered and regulated linearly down to 12v bipolar and filtered again.</span></div></blockquote><br class=""></div><div>OMG, that sounds complicated! And that is a better? cheaper? lighter? alternative to an old fashioned linear PSU??</div><div><br class=""></div><div>A</div><span>_______________________________________________</span><br><span>Synth-diy mailing list</span><br><span>Synth-diy@synth-diy.org</span><br><span>http://synth-diy.org/mailman/listinfo/synth-diy</span><br></div></blockquote></div></div></div></body></html>