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
Albert, Jcbtubes -

My system, while not ultra-high end, is quite enjoyable and pretty revealing:

Pioneer 525 DVD/Marantz CD63 mkII feeding an MSB Link DAC III;
Plinius 8150 integrated amp (w/apologies to Redkiwi's countrymen, this might be the weak link in the system);
Dunlavy SM-1.

Pretty nice sounding, but if anybody wants to send me a really good subwoofer I'd certainly not object! By the way, there's no lack of aftermarket PCs in the area. Within 15 miles of home, there are 6 bona-fide high end stores and a couple of mid-fi stores with a smattering of better stuff. At one store, you could listen to the $85k Dynaudio Evidence with a Krell Master Reference sub. They also had the Krell Master Reference amps; I think this is what led to the power crisis in California!

Cheers,
Jhunter
Jhunter, your system may not be the absolute ultimate in audio, but it is certainly high quality and capable of resolving the differences between power cables. I would love for you to audition a couple of cables that are very different from stock and from each other.

Perhaps Purist Audio Dominus and maybe something like a Siltech. I would not tell you in advance that the performance in your particular system would be worth the investment. I am certain though that the test I outlined, employing long term listening with one of these, then returning to the original power cord will provide an easily discernible performance change.

I would love it if you tried this and then posted your comments as to what you heard. You don't have to agree with anyone, much less me, but finding a new tool to make your music better would be exciting. If you do this test, and tell me in advance what you like and dislike about your system with the stock cords, I think I can almost guess which of these two aftermarket cords will make you happy. It could be a fun experiment. I will not be unhappy if I fail to guess right, and should you find something that works better, you are the winner in the end.

Last, I could possibly supply you with an Acrotech and a pair of old Tiffany TPC 60's. These would be fairly easy to tell from stock. This offer is in case you cannot borrow the suggested ones from a store. I could possibly loan you a Purist Dominus if I can find a spare. They are expensive, so I don't have much in the way of extras laying around, but I am willing to look.
NEW CHALLENGE is afoot! Count me in. I would be willing to "lend" a power cable to Jhunter as well. I have a pretty good Synergistic Research not in use. I would be happy to send it along to Jhunter for a few weeks. Same test conditions as Albert Porter suggested. Plug it into a component, let it settle in for two weeks, then replace with stock power cord. If you can honestly tell yourself that you do not hear a difference, send it back to me and I'll cover shipping costs back. If you do hear a difference, send it back to me anyway, or maybe we'll make a nice deal because you can't bear to part with it ;)

I'm game, how about you?
Hi JHunter,

I now have three NBS Statement power cords, two on my bi-amps (Aloia) and one on my SACD
(SCD-1) player. I have BMI Whales on the pre-amp and suppling my PS300 conditioner.

I have actually done a lot of testing with power cords with these same guys over the years. We have had sessions where they or I are blindfolded and we will try two, maybe three cords. The trick of not switching is a good one to see them squirm, but I've found it meaningless. My experience is it's almost 50/50 as weather they heard anything. I've tried to inject the no switch test a few times in one night and all that happens is confusion from the listener, and then they begin to doubt everything they hear. I'd say my experience with that trick is it may actually be counter productive and invalidates earlier findings.
This blind testing has become a game for us, it's fun to see how well we pick up on subtle changes.
It's not ABX, but I insist the results are as good or better. I have two amps, exactly the same model. We've played with switching between amps with exactly the same interconnect model, of exactly the same age. We have found one of the amps to be a bit better in it's high range than the other (guess which amp is wired to the bass and which to the midrange tweeters). I suppose it could be burn in because they were bought at different times, of it could be shelf placement, or one having cleaner terminals, I happen to believe nothing man made is exact, and two identical pieces are never identical. This is why I believe my testing methods as described many times here on these threads provide more valid results than the clinical approach demanded by some here. It's funny that the demands keep coming for tests, but there are no attempts at real tests by these guys, and a flat un-acceptance of the results reported by so many here on Audiogon. I guess again I'm proven too stupid to understand there higher life form. Happy testing, oh ah listening, no enjoying the music, wasn't that the purpose?
J.D.
While not cable related, an an anecdotal exchange occurred this past weekend that gives an interesting bit of insight into how some people's training is almost akin to brainwashing.

A couple of friends helped move my large items like furniture to a new place. My system had been moved and set up a week ago, though it is still going through fine tuning for the room.

Both of these friends are mechanical engineers. Rex is a vibration control expert who's into home theatre. We've had many a lengthy, often times spirited, exchange on equipment. Rex is, for the most part, a non-believer in tweaks and cables (after a point). This was the first time he's heard my system. John, as I've described before, is an acomplished musician and has spent many an hour in my living room listening to music. He knows my system almost as well as me.

The work finished we settled in for a couple of beers and a demo for Rex' benefit. Unrelated, but I found it interesting that Rex, Mr. HT, found it necessary to drive the volume far beyond what the room would handle. Not just as a test of its limits, but as a chosen listening level. He did exhibit a good ear by pointing out a shifting image in the soundstage I hadn't found yet.

Anyway, at one point Rex picked up a spare set of Black Diamond Racing cones that were lying next to the rack. The gist of the commentary was that all tweaks are "snake oil", that nothing in his training allowed that they could possibly do anything to effect the production of sound. He and John kidded about going into business making something that *seemed* exotic and how well it would sell. Then I made a mistake. I reminded John about an experiment we'd done with the BDR cones. One afternoon we had put a spare pair under the pre- and, he admitted, then and in this conversation, that it *had* changed the sound. He blubbered some excuse to Rex about not being able to quantify whether it was an improvement (his otherwise good memory suddenly failing him) and the subject was quickly changed.

While helping me return the moving van John took an opportunity to mildly chastise me for embarrassing him in front of another professional engineer. He was obviously torn between his education and that of a respected colleague's and first hand experience.

It's at times like this that the fact I am, for the most part, self educated, has great value. It has not been drilled into my head that "this is *always* the case" and the ability to see things for what they *really* are is still part of my faculties. It's unfortunate that education somehow has taught these otherwise intelligent people to believe books before their own senses. That's not to say education is bad, just that the rigid thinking it promotes is one of its downsides.

BTW, I know deep down John is actually a convert as he's been around while my system has matured. He's seen what various cables and tweaks have done, both good and bad. Rex doesn't know it, but he's next.

Redkiwi: Your last post shows we're somewhat in agreement. I would gladly participate in an exchange with the members in question if it were an open minded exchange. I simply refuse to participate in circular debate. It serves no purpose except to occupy space and time. That and it frustrate me. Apparently you, too, after awhile.