Soo this was the first mult design I built and it served me well, but I know it is very basic. I think it was originally from a LMNC post but I couldn’t find it on his page and he had since upgraded to a design where every output is buffered which is arguably the better solution. None the less this is one of the most used modules in my system and I can only recommend it because it only uses one quad-opamp and is a very easy and cheap build.