Head over here and listen to the two examples of common hum in an audio system.
Please note that drivers can and do cover up issues in sound quality. It sounds like your new, more complex system is creating new feedback, or is now helping you discover a problem that has been there all along.
I always look for a proper earth ground - yes, folks still get bit by bad grounds, and audio is one of the easiest ways to discover it. I keep a HumBuster with me when I occasionally need it to fix a ground loop or an effect from nearby equipment.
Even if the Linux drivers do not pass the offending sound does not mean that there is not a problem.
BTW, which video cards are you using, and with which motherboard?
All these things do make a difference.
It's a voice:
"We are your friends, chuckles, but you have to stop trying to resist us. We are your friends, chuckles, but you have to obey."
Regards,
It’s not ground hum, more like static every couple of seconds. I would describe it like twisting the connector in the audio jack. I have wiggled and twisted it 100 times and that doesn’t cause the noise. The noise just happens on it own. Also headphones make the same noise but cuts off the whole speaker system. Even USB digital speakers make the same noise. I’m using a Geforce GT 610 and a Geforce GT 710 for video. I have a Bluetooth speaker that has no noise.
Good advice. A floating ground is never a good thing. I recently had to replace my 60+ year old water pipe from the street with PEX. The very next thing I did was call an electrician to install a dual grounding rod system along with EATON Surge Protection. In my forty year career in telecommunications I've experienced several grounding problems along the way.