themystical

Thanks Kevin. That is what I have done. I have balanced inputs so the signal/chassis ground is isolated from the smps and amp board grounds. In other words the smps power ground and output signal negative is floating and not tied down. I probably need to do a bit more experiments to try and identify the issue I.e. whether it is conducted noise from the SMPS, EMI pick up, earth loop etc. I was just wondering whether there was some standard EMI suppression filter required with SMPS?

https://flic.kr/p/2kmuC9i https://flic.kr/p/2kmqddS I have used the holiday period to build this amp but I am unfortunately having a mains hum similar to some other builds. Not having used SMPS before, am I missing a trick? Is there some sort of filter that I need to insert to make it hum free?

Seems to be working really well!! Any comments/initial reaction on SQ with and without base boost? How warm is the heat sink getting? Could it be much smaller?

I have ordered some of these PCB’s ( 2mm copper) so if somebody is interested please PM me. Probably makes more sense in the UK or EU because of shipping costs I suspect.🙂

Thanks very much Kevin

This might be a silly question but I have never worked with SMPS’s before. Are the two power supply modules connected together to provide +-24V DC and then connected in parallel to both channels or is each module dedicated to each channel

Really? You think they will do 5 of these at 4oz copper for that price? That would be the bargain of the century! I will give them a try. Thanks very much.

If somebody is going to get these PCB's fabricated, I would be interested in a couple. Please PM me so that we can share costs?