That was even worse--the noise was just as loud, but the signal softer.

And I do mean amplifier hiss (which you can't fix) and not ground loop noise (which you can but expensive)

A quick search online for "GPU ground loop under load" would list you the many cases where only during gaming, the speakers would start to buzz as if electrical noise is leaking into them

That being said, there is a SMALL hissing noise when these are idling.

The hissing noise isn't really an issue unless you have no sound playing