The most immediate solution is in eliminating grood loop from your cable rather than the AC power.
Try:
Ground Loop Eliminator from Audio Advisor ($100).
http://www.audioadvisor.com/store/productdetail.asp?sku=TRIBGG1
Ki
Try:
Ground Loop Eliminator from Audio Advisor ($100).
http://www.audioadvisor.com/store/productdetail.asp?sku=TRIBGG1
Ki