If so - you might have a 'ground loop'

You can safely, and permanently remove the ground loop hum at the source with the
HUM X!
The
HUM X filters out unwanted voltage and current in the ground line that cause ground loop hum, while maintaining a solid and safe ground connection.
Simply place the
HUM X on the end of a 3-prong power cord of the equipment that has a ground loop. The ground loop is gone - and the audio signal remains intact!
Check out
www.ebtechaudio.com for more info
