Your plug has three prongs, the positive, the negative, both of which are flat, and the ground which is round. You will in essence be disconnecting the round ground prong. To do this go to you hardware store and get a "cheater plug" this is a plug which has three slots for your plug but only has the two flat prongs - these you plug into your outlet. Do not connect the ground wire on the cheater plug to anything.
Slight hum from left speaker -- Help appreciated
Two weeks ago I installed a new amp and preamp (Pass Aleph 30/FT Audio LW-1) in my system and since then I've had a very slight hum from my left speaker. It's not distracting, but it's something I'd like to get rid of. I've switched out interconnects and speaker cables and nothing changed. I did a search for ground loop hums and I could not find any useful information other than cable TV may be a problem and we don't have cable. Any hints on what could be causing the hum would be greatly appreciated. Thanks!