If you don’t have a cheater plug available you might be able to fit the EP800s power cord to an old two prong extension cord if you have one laying around.
Also just for kicks try plugging it into an outlet on a different circuit and see what happens.
*vibration stops when I unplug the cable from the line in BUT if I touch the line in jack (or the line out jack for that matter) with my finger, it vibrates again.
I would call Axiom and see what they say if your getting the hum by completing the circuit with your finger.
