How can power cords make a difference?


I am trying to understand why power cords can make a difference.

It makes sense to me that interconnects and speaker cables make a difference. They are dealing with a complex signal that contains numerous frequencies at various phases and amplitudes. Any change in these parameters should affect the sound.

A power cord is ideally dealing with only a single frequency. If the explanation is RF rejection, then an AC regeneration device like PS Audio’s should make these cords unnecessary. I suppose it could be the capacitance of these cables offering some power factor correction since the transformer is an inductive load.

The purpose of my post is not to start a war between the “I hear what I hear so it must be so” camp and the “you’re crazy and wasting your money,” advocates. I am looking for reasons. I am hoping that someone can offer some valid scientific explanations or point me toward sources of this information. Thanks.
bruce1483

Showing 3 responses by liguy

Nrchy, don't start that scientist crap again. I am sick and tired of reading the sos.
I don't know how many of you out there have read the Mike Van Evers explaination of why power cords make a difference but IMHO it makes no logical sense at all. Any other comments out there?
Gumby, I would be willing to bet that in a better piece of equipment the power cord never sees the severe changes that you talk about. I do agree that the AC side of the supply does see changes in current demand but if there is sufficient filter capacity just after the rectifiers the greatest demand for power should only be when the amp is powered up. This is true simply because an uncharged capacitor looks electrically like a very low resistance.
Once the caps are charged, the demands of the amp are borne by the filter caps which in turn is charged by the rectified AC from your transformer and power cord. I think that a well designed power supply with a hefty set of caps renders the expensive cords impotent. I do however hear differences with different interconnects and speaker cables.