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
To ALL- I regret that I can sometimes take things too seriously. This is supposed to be fun.
To JHunter- I do apologize for my diatribe. I recented communicated with Brulee and discovered that in fact you have been discussing the listening issue further. Though I did attempt (twice, actually) earlier to add a response stating this, the Audiogon server wouldn't accept my follow-up till now.

May I add, as has been detailed in other responses, that A/B testing of audio equipment is not a trivial task. Power cycling of equipment and equipment (cable) movement can take a considerable amount of time to restabilize. This can severely limit the number of swaps possible in a week, let alone a day. Also, conclusions based on other's perceptions really aren't as valid as those based on your own experience.

To this end, I'm willing to offer a Shunyata King Cobra (moderately flexible but thick and heavy) for audition (with some reasonable form of deposit) for a week in your system. (I'd offer a FIM, but it seems Brulee has already offered one). Though your system is unknown to me, I will assume that it is a true attempt at hi-end aspirations. My opinion is that you will easily differentiate between a stock cord and the Shunyata. (FYI: the King Cobra will have to be installed and not moved for a couple of days before it will perform at it's best. It's internal construction requires settling of the proprietary "dust" used for emi/rfi absorption. Also, I'd recommend that you place it on your front-end equipment first.)

If I may, I do find that knowledge through personal experience is usually worth much more than money. This is what I was refering to as "for your benefit". For someone to offer to set aside their time (and Brulee has, I seem to recall, refused any monetary compensation) to help enlighten you, certainly fits my definition of "for your benefit".

I allowed my cynicism to get the better of me. I must assume that you are sincere about listening to power cords yourself with some semblance of an open mind, regardless of some of the comments that you've previously submitted. However, it does seem perplexing that you haven't commented about attempts to contact any dealers concerning pc auditioning. I'm sure that I and others on this thread can help direct you to several so that you can participate in this endeavor yourself. Please contact me if you are interested in auditioning the Shunyata pc.

Jcbtubes
Jhunter, in response to your "honestly, honestly don't understand why people are reluctant to evaluate components in this fashion". I can only give you my reasons, but suspect that they may overlap with others'. I find ABX testing provides far too short a listening experience where the listeners are trying to discern differences in the equipment, not trying to enjoy music. It is my opinion that we all try to objectify too much when we describe how a component sounds, and that we are better to just try relaxing into the groove of the music when evaluating equipment. I have learnt when evaluating a component to just put it in place and then forget about it. After a few days, maybe a week (ignoring burn-in time) I get a sense of how much I am enjoying the music. When I am not enjoying it I start to get objective and try to identify what is going on. When I have developed a hypothesis I test it by swapping out the new item for its predecessor. Sometimes I get an overwhelming sense of relief from doing this, not always easy to objectively describe, but clearly the new product had been reducing my ability to relax into the groove of the music.

I don't think that what an individual needs in order to get enjoyment out of music is easy to objectify, much less measure. This is because electronically recorded and reproduced music is not the same as the naturalness of the real thing, and in order to recreate the feeling of the real thing the brain has to do a lot of work. Exactly which distortions tax the brain most, or distract the brain most from relaxing into the groove are not captured by measurements of THD in my experience.

I find that in ABX testing (which I have had some experience of), I can only readily identify what I perceive to be differences relating to tonal colorations, grain, dynamics and transparency. I often find that understanding the differences in PRAT, for example, or naturalness of the way sounds start and stop, as another example, take me longer. I theorise that this is because these issues only become meaningful when you are just trying to enjoy the music, not when you are trying to objectify the sound. And yet these two issues are critical requirements for me in a music system.

And by the way, I have reported elsewhere here the results of an ABX test I did with two other listeners with respect to power cables. The differences were readily discernable for me even in an ABX, because there were clear differences in that the stock cable imposed a grain on the sound and suffered some upper-midrange ringing.
Jhunter. You are certainly welcome to listen here anytime you are available. Advance notice of a few days would help, and I am willing to pick you up at the airport and treat you to dinner.

My reason for assuming that audio tools are not important to you, is due to the challenge you made to everyone here at Audiogon. Primarily, your obvious pre assumption of failure for all of the aftermarket power cords. Further, by injecting money into the equation, you set a mood of smugness in your certainly as to the end result of the tests. Your procedures are another ABX topic with a softer sell, and is a subject that has been declared off limits by Audiogon as counter productive to the discussions of advancing music systems.

This is of course, why I made an alternate offer. It is elegant in it's simplicity, and does away with the problems of cycling equipment, multiple movement of the cables, and undue pressure on the listeners. I have faith, that even knowing in advance which cable is which, you will not be biased to choose only the stock wire. If you arrive with an open mind and audition once each way, in a relaxed atmosphere, you will conclude that high performance power cables not only work, but are essential to the system.

My concerns regarding your equipment is natural, considering the experience of myself and others in my group ( including the Grammy award winner ). Our gains were so dramatic, as to be impossible to ignore. I assumed that you either never auditioned any high end power cables, or your system failed to reveal the improvement to you. If you have experimented with these products, your opinion certainly brings into question the validity of your system to serve as a test bed for this experiment.

Each must ultimately judge how much time and effort to invest, and whether the performance balances the expense. I do not expect the same level of commitment from every person that enjoys listening to music. I do however, bristle at those that limit their options, and in their own judgement, claim everyone else to be wrong. I have gained knowledge only by keeping an open mind, and experimenting with the tools that were claimed to be of benefit. Certainly there are more failures than successes, but ultimately, you receive in return almost exactly what you invest.

I sincerely hope to have an opportunity to share this with you. I believe you will find ours a passionate group of dedicated musicians, engineers and audiophiles, all sharing a diverse software library, seeking only the opportunity to make the music and the system the best it can be.
Frap: A lot of people want the "tube sound," even at the expense of a couple percent THD. That's fine. I know you can make tube circuits without that distortion, but that's not what most seem to want to hear. For the "nice sound," tubes are great. For accuracy and neutrality, I pick solid state. And actually, for a while I was experimenting with FETs to get the tube-like transfer function. That was fun, but I didn't have a practical application for it.

IMHO, the audio pioneers (not only design, but also techniques, science, etc.) included Bell and Edison, of course, but also Helmholtz, Fletcher and Munson, Alan Blumlein, Edwin Armstrong, Jack Mullin, Paul Klipsch, Ray Dolby, Rudy Van Gelder, Stanley Lipshitz, Julian Hirsch, Eugene Patronis, Kees van Imminck, John Eargle, George Martin, Harry Olson, F. Alton Everest, and many more.

Brulee: No, I did not make a boastful claim in saying that PCs do not make a difference. I've designed, built, modified, and repaired many dozens of power supplies in audio gear, and the claims that the cable purveyors make are just downright silly, just as a claim that designer air in your tires would seem silly to an automotive engineer or to a mechanic.

Do I believe that you, Jcbtubes, and others are hearing things that aren't really there? That's a very strong possibility. Sound is invisible and temporal, our hearing varies with conditions, and aural memory is evanescent. Thus, audio is susceptible to biases, misjudgment, and misperception.

BTW, what CDs did you get?

Jadem6: I don't know what you're saying. Are you saying that building Heathkits is more instructive to audio design than studying acoustics, electronics, music, psychoacoustics, etc.? Man, I've done both. I guess I could've save myself some time and tuition, eh? I'm delighted about your practical experience, but I enjoy the fruits of my own even more. If you feel that true audio excellence is attainable only by spending megabucks on power cords, well, I guess your peasants are pretty damn wealthy and out more to impress than to listen. I don't object to your spending big bucks on such things; if anyone should spend his money on snake oil, I have the least objection to your doing so.

Jcbtubes: I will add the adjective "untrue" to your latest "boastful" statement. I've heard many, many audio systems of exceptional quality that had nary a designer PC, and couldn't possibly be improved by adding any. If slavish and worshipful devotion to every cockamamie marketing scheme meant to separate audiophiles from their money is being a "winner" musically, I'll let you have that one.
702, it sounds like you have played with as many power supplies as me. And yet unlike you I don't find exotic PCs silly. I did find them silly before I tried them though - which I guess is the difference between you and me. You illustrate this point even further when you comment about "exceptional quality systems that ... couldn't possibly be improved by adding any [PCs]." How can you know that if you didn't even try.

You see I think your mind misunderstands useful theory as completely explaining natural phenomena, and you simply deduce everything from that theory. This is not scientific at all, it is pompous and short-sighted. (I don't mean to be insulting because I am guilty of being pompous and short-sighted about things I am highly educated in - usually the ones I am most educated in).

Where I do agree with you is concerning the ludicrous claims of the marketers who are paid to sell audiophiles on manufacturers' product. Anyone that has a business with shareholders is obliged to do this. You tell them what is legal, but otherwise anything that will sell the product. Some of the advertisements and "piffle" on web sites is a hoot. But there is only one difference between the audiophiles that fall for it and yourself - the fact you are better educated in electronics theory. Otherwise they are just like you and deduce from a scientific theory whether something will be beneficial or not. You and they fall into the trap of believing in the completeness of a theory.

For example, there might hypothetically be unequivocal evidence to your satisfaction that a shielded interconnect cable will sound better than an identical unshielded cable. And so as the hypothetical pioneer of shielded interconnect cables I might write some convincing rubbish for the masses that gets them into a lather that they just have to have my cables. Both you and the ignorant masses would be wrong to conclude that my cable was better than all other cables, provided there was some other parameter that affected the performance of a cable. Hypothetically my cables might use steel conductors and a competitors' might use copper. The dilemna that you do not address is how do you decide whether the shielded steel cable will outperform the unshielded copper cable. The answer seems simple to me - you listen to them. For you it appears to me that you would prefer to see what a 'scope tells you than by listening. But how can the scope identify which form of distortion is most likely to reduce the listener's enjoyment?

Of course the example includes two issues (shielding and conductivity) that you probably accept as influential on the sound, and a dilemma that can be resolved - ie. get a shielded copper cable. But it is not always that simple. And where we have the problem incessantly in these argumentative posts, is where experienced audiophiles hear a difference, and you deny that report because of your pompous and short-sighted belief that you know everything that there is to know about reproducing music electronically. Frankly 702, that is just as much a "hoot" as some of the claims of the copywriters working for the cable manufacturers.