Interference noise

Yup... ground loop likely.

Maybe you can minimize by plugging everything into the same circuit(powerstrip), using only quality cables, and a little bit of luck.

Big problem is, many electronics hardware and their connections aren't properly isolated from their chassis, just adds to the ever present annoyance of electromagnetic induction.

Happy hunting.

Thanks! I've tried few things after you suggestion. AC outlet doesn't matter, it makes noise even when Gaia is not plugged into power outlet. Tried using HUB, different USB cable, nada... Finally tried balanced TRS cable, and it solved the problem!

Nice to hear!!! (without the noise even)

Balanced interconnects are always choice when available. Glad they solved your problem; sometimes even those circuits don't work as great as they should.

I'm surprised more people don't have the same thing happening now that nearly everything connects via USB, it seems the ports are prime culprits for passing along stray voltage.