How can power cords make a difference?

Jay, I always wash my brain with Kontak, and chase it with bleach. It helps me hear power cord differences better. Don't knock this tweak til you try it. It also helps clear up some of my other brain problems.

Same here Elizabeth. A realist by nature (some might even say pessimist but I don't think the affliction is quit that advanced) I tried a "designer" cord on a whim. Fully expected to notice no difference. On the source (DAC or transport), where others claim the most benefit, there was no appreciable effect. Putting it on the preamp was another story. The sound was more "musical" and lively. On the amp the difference was VERY noticeable. Here it brought a considerable increase in the heft of the low end and at the same time the overall sound was less strained.

Bought another cord to put on the preamp. Ah, the best of both worlds. Eventually my anal retentive nature caught up and now everything has an upgraded cord. The source didn't really *need* it, but what the heck!

Ultimately it paid off that even as a doubting Thomas I was willing to try something new. If only that attitude could be bottled...

Albert - This isn't personal. I like talking about hifi related things. I don't get upset if someone says that their line cord makes a huge difference. I find it interesting. I don't judge people by whether they use expensive line cords or not. I have friends with whom I disagree about important things. Like you, I am just expressing my opinion. I don't like fighting and I take care not to write anything that sounds personal. I state an opinion and try to back it up with some information. I thought you might find the line cord voltage numbers interesting. It wasn't written with the intent to agravating you or with the expectation that you were going to read it and cry out "MY GOD, how could I have been so wrong!?"... And, I'm sure that if I had a chance to hear your system I would agree that it sounded damn good.

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.