The input terminals on the back of all powered audio equipment, and thus the equipment's performance, is affected by two things, the input voltage and the frequency. I think the marketing success of special power cords, comes from their ability to convince the buyer that there are other "spooks and goblins" in the electricity that can somehow degrade audio performance, and that their product fixes these issues. All that is required for any well designed component to perform to it's maximum potential is that the power supplied to it be 110V/60Hz power. If the wall outlet supplies these requirements, there is nothing that any power cord can do to improve it.