Ah,you may have a grounding problem.Recheck the outlet ground and more importantly the ground connection at source.
If you have a basement you can drill a hole in the floor and drive a new ground rod.Run a separate ground wire from your outlet to this new ground rod.If you have an outlet like from PS Audio which has an isolated ground this is perfect because your outlet box and stuff is grounded normally and the isolated ground is all that is connected to our new ground rod.They may be i dunno $100 or something but the best improvment period in reducing noise and of course less noise means more music.Hope this helps.
Peter
If you have a basement you can drill a hole in the floor and drive a new ground rod.Run a separate ground wire from your outlet to this new ground rod.If you have an outlet like from PS Audio which has an isolated ground this is perfect because your outlet box and stuff is grounded normally and the isolated ground is all that is connected to our new ground rod.They may be i dunno $100 or something but the best improvment period in reducing noise and of course less noise means more music.Hope this helps.
Peter