I'm about to build a pretty simple PSU for my modular synth project. I'm looking at a few schematics from popular sites and I've previously built a simple wall-wart one based on this from MusicFromOuterSpace, http://musicfromouterspace.com/index.php?MAINTAB=SYNTHDIY using LM7912 and LM7812.
There are also lots of kits with these 7812/7912 pairs like https://www.banggood.com/DIY-LM7812LM7912-Dual-Voltage-Regulator-Rectifier-Bridge-Power-Supply-Module-5V-12V-Kit-p-1363569.html?gmcCountry=SE¤cy=SEK&createTmp=1&utm_source=googleshopping&utm_medium=cpc_union&utm_content=2zou&utm_campaign=pla-all2-se-en-pc&gclid=Cj0KCQiArqPgBRCRARIsAPwlHoXE9RgOOi3wlJ44WgDhjwz376YPlV3aI21Tsu0PF-d2THapEru2bzUaAqCAEALw_wcB&ID=557391&cur_warehouse=CN
But then I watched this video on capacitance multipliers:
and just don't understand why this isn't used everywhere? I guess I'm missing something.
What I mean is, it seems to be a really big thing to really reduce ripple on power for synth applications. The schematics I'm looking at are sticking really really big electrolytics in there to do that - it's like that's probably the big material cost for these PSU's. Like 10kuF or so. Wouldn't it be a very simple win to just use a mosfet capacitance multiplier just before the voltage regulator?