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 1 response by kurt_s

Dear All,
I've certainly read a number of interesting theories on why PCs make a difference. RF/EMI rejection, bigger guage "pipe" to supply electrical power, bandpass filter effects, various sound differences between metal types and purity, mechnical vibrational effects, soldering techniques, noise cancellation techniques and the dielectric content to name a few. Here's a thought. I've read about but never experienced the PS Audio PowerPlants. I've read that changing the output frequency can effect the sound. Sometimes better, sometimes worse. Perhaps the PC is merely removing certain frequencies from the incoming power or modifying the wavelength (or waveform) slightly.
I know that adding Uninteruptable Power Supplies (UPS) to complex laboratory medical equipment makes them run better. Repair costs go down, system failures go down, mechanical irregularities go away and precision improves. D/A and A/D convertors certainly work more consistently. There are power supplies inside the equipment that should protect and clean up the power. I've noted times when the power monitors showed no spikes or brown-outs but the UPS aided equipment ran better. So what's up? Personally, I don't know (I was a chemist not an EE). I can usually hear differences between PCs. Sometimes I like them, sometimes I don't. Hey, enjoy the music. It's not worth fighting over.