Well, my interconnect cables will sometimes pick up hum from nearby power cords, or even nearby equipment. I will try to get them away from such 'problems' by routing the interconnect a different path, so it is not so close to the offending cable/equipment. You might even try moving the interconnect cable around and listen for hum as you move it. If that is not the problem, then let's look to the position of the Quickie itself. Is it close to another piece of equipment? I say this because you have hum in one channel only, and that indicates a possibility of one side of the Quickie being affected by the magnetic field of the offending component. My Quickie ha to be away from my amp at least 4 inches or the left channel will have a slight hum. Hum can be tricky to find. Rarely I have even found a component UNDERNEATH the affected unit! The shelf below. Out of sight, out of mind.