I hate hums and whines. When I was using mobo sound, evrything was quiet, 'cept it sounded krappy.
Bought a Creative Soundblaster PCI card - enter hummmm in only one of my amps. I measured voltages, changed grounds and locations...generally killed myself looking for a sol'n.
Decided to ignore the dire warnings, and purchased a Radio sHack ground loop isolator (gli) for $17. Problem solved, and there was NO reduction in audio quality.
I hate hums and whiles.
Best luck and blessings with your noises....