Here's my suggestion. Hook the Presonus up to something else that has nothing to do with your computer and see if you get the noise you're talking about. If not, then hook up those USB speakers your tech was working with, and see if they have the same massive static that your system shows. If not, that's good. Then it's somewhere in your system.

Since the mainboard, PSU, video card, etc have all been replaced, pull the SSD out and and boot to Linux and see if it still manifests itself. If it does, pull the hard drive cables so there's no power or data going to the hard drive.

I doubt very much if it's the CPU, but it wouldn't surprise me if it was the SSD drive. By the way, any tech that spends two days on this is either working on a whole lot of other stuff, or doesn't know what he's doing. It should not be that difficult to track down by process of elimination where the noise is coming from.

Gary

I'm blessed watching God do what He does best. I've had a few rough years, and I'm still not back to where I want to be, but I'm on the way and things are looking far better now than what they were!