John is right on.
(And Narrod is way off -- contrary to what he might think without having tried it, these things *can* be heard by careful listeners who don't believe in fairy dust).
However, as far as changing cords on the ExactPower in particular goes, when I change the cord on mine I don't hear quite as much of a difference as when changing cords on individual components which follow the ExactPower. This makes sense to me given what the EP is supposed to accomplish, but I still do find it worthwhile to use an upgraded PC here, and different aftermarket PCs do lend a different overall system sound, with some being better than others.
(And Narrod is way off -- contrary to what he might think without having tried it, these things *can* be heard by careful listeners who don't believe in fairy dust).
However, as far as changing cords on the ExactPower in particular goes, when I change the cord on mine I don't hear quite as much of a difference as when changing cords on individual components which follow the ExactPower. This makes sense to me given what the EP is supposed to accomplish, but I still do find it worthwhile to use an upgraded PC here, and different aftermarket PCs do lend a different overall system sound, with some being better than others.