Edifier S350DB whine issue

I picked this set up recently and after a few of days chasing this issue I’ve found that the speakers have a high pitched whine coming from them almost all the time. It comes and goes, changes pitch, but is noticeable most of the time during silence/idle periods. The whine happens on at least the PC, AUX, OPT, and Bluetooth inputs. I don’t have a coaxial to test that input, but it probably would happen there once activated.

This appears to be something common enough for folks to investigate and post about elsewhere as well:

Even someone opened the amp up to look at the board to see if something could be identified:

This person has some speculations about the integrated circuit used for the 5V power supply but I’m no electrical engineer.

Would it be OK to try my luck with Edifier support, or should I just box them up and return them now? They’re completely unusable with this high pitched whine.

Is there another 2.1 system that has optical input like this one does? I was looking at the Swan M50W as recommended by Zeos, but it not being available anywhere I looked, and no optical input was a deterrent for me. I didn’t see any other reviews of 2.1 systems by Zeos. The variety of inputs on the Edifier is nice because it gives me lots of options, and the optical input is not affected by RFI.

Could I get a similar setup for a similar price with separate components? Like DAC + Amplifier + 2 Speakers + Sub (Powered?)? I’d really like to have the sub component. Even the S350DB isn’t impressive with its low-end response though it also has a sub.

I had this issue as well on my second set and they gave me a replacement fairly quickly.

Their support was not helpful, but at least they did respond relatively fast. They didn’t acknowledge this apparently fairly common issue. I’ll be returning this system, and since the Swan M50W is impossible to find, I’ll probably be better off building my own 2.1 system from components.