Discussion of power cords

[shelly_d]

I am starting a new thread for this opinion to avoid carping on another ongoing thread on this forum. The idea that the power cord can make an audible difference in what you hear. Understand that between the power cord and the amp circuitry is a power supply that will isolate the power cord from the amp. That power supply contains a transformer, rectifier, filtering caps, sometimes a filtering choke and sometimes a voltage regulator. Any subtle changes that a power cord could create (and I dispute that they can) are lost in the intervening circuits. It's a power cord folks! Nothing more.

What's its job?

It carries the line current from the outlet to the power transformer. What could it bring with it? First you can consider RFI/EFI from outside. Well that's going to be what is called common mode noise, that is induced across BOTH the hot and neutral leads. The transformer responds to the DIFFERENCE between the two leads so that won't make it through the transformer. Then there is the noise on the incoming line that is different between the two lines. That's there at the outlet. The power cord simply transports to the power transformer, so unless there is a power conditioner built into the power cord, the cord can't do anything about that. Well, then there is the claim that the outlet can grip the cord better. Well here there could be some claim. The outlet and the IEC connection has to be solid and secure to be safe. If the plug is loose in the outlet that is a problem and needs to be fixed for both audio quality and safety. Best fix - replace the outlet so that ALL devices plugged into the outlet are held securely. Get a Levitown for $5 ~ $7 (probably overpaying) at your local hardware store. Once you have that and you are gripping the plug well, any further "improvement" won't improve sound quality. Why is that? There is a physical connection between the outlet and the plug. It contributes, usually, less then 1 ohm resistance between the power feed and the cabling inside the power cord. Assuming that your amp draws perhaps 1000 watts at high power, that is about 8 amps peak. At a full 1 ohm resistance (really quite high for the connection) that represents 8 volt drop across the plug. Now lets say you improve the cable and manage to drop that resistance down to .25 ohms. (That's a huge change for something like this). Now the voltage drop is down to 2 volts. So you now have a 6 volt change feeding the amp. At 120 volts a 6 volt change represents a 5% voltage change. The standards for power delivery allow that much change across the full range of their transmission systems. That is, if your voltage is anywhere between 115 volts and 125 volts your power is normal. Your amp is designed with this variation in mind. If you have a voltage regulator in your power supply, by providing the increase in voltage, you increase the load on your regulator circuit which just dissipates the added voltage and resulting power as heat and never affects the amp circuit at all.

But what about all the people who say they hear a difference. Here is some real facts from human sensory research. The one sense that we have that has the shortest retained memory is hearing. The one sense that is easiest to influence by presuggestion is hearing. If you read or hear that the treble is going to be improved, you will start listening to the treble more closely and notice more even when there is not change. That's just the way we are. All of us. Its not that we are weak minded, its that we all have this suggestibility. Marketers know this and depend upon 2 things, one that its true (and it is) and that most of us do not know about it and allow for it when auditioning new equipment. Therefore if say Wattgate claims that their power plug will do wonders for your stereo for just $77.90, and that you will hear the difference, they are depending upon the suggestion that things will be better to influence what you listen for and therefore what you hear. (http://www.revolutionpower.com/p/WATTGATE+330i+Audio+Grade+Gold+Black+Connector+Plug/310/) This is not to say that you are not hearing what you think you are hearing, far from it. What is happening is that you are noticing the particular qualities more after the install simply because you are listening for them after the install. In short its a game played by marketing operations to separate you from you money.

I know this is a controversial opinion and I invite opposing viewpoints. Please do not get personal. This is about the so called audiophile power cord industry and their marketing tactics.

To those who would like to learn more about that human sensory research that I mentioned. I am truly sorry but I remember reading about it some time ago but I no longer remember where or how I stumbled across it, so no, I am sorry, but I cannot post links to it. A glaring defect in this post and I apologize for their absence.

Shelly_D

 

[petehall347]

the power cord itself shouldn't make any difference unless it is too thin to take the current .. a problem can be caused by interference from the cable so shielding or twisting the cables or fitting filters to the cord may well make a difference .

 

[shelly_d]

And maybe I should proof read better - poer for power???? :sigh::worried::screwy:

 

[luvvinvinyl]

And maybe I should proof read better - poer for power???? :sigh::worried::screwy:

:yes:

Fixed.

 

[redcoates7]

I take the same approach with power cords as all other cabling in my system. I use adequately heavy gauge to carry the current in question, adequately flexible so that they work in my installation, mechanically adequate for the work they're expected to do (good quality connectors, so on) and lastly nice enough looking that I don't hate the sight of them...

Not very scientific, but it's always worked for me!

 

[ehoove]

In a high resolving system they do make a difference, but it is a real point of disagreement to some. My system has great resolution and the difference when switching different cords back and forth is apparent to me, but what do I know? I just trust my ears. It seems to make a bigger difference on sources than power amps though.:scratch2:
Regards,
Jim

 

[RichPA]

My experience says they can make a difference. I can't say that I know for sure why, but I am very confident that not all power supplies are designed to provide adequate isolation from crap on the power line.

 

[luvvinvinyl]

If power cord A cannot perform audibly better than power cord B, then the converse must also be true, yes?

i.e. Power cord B cannot be worse than power cord A, for any power cord B.

Likewise, the discussion always seems to centre on a 'high-dollar' cord out-performing a 'budget' cord. If, for the sake of argument, we set aside the question of whether a power cord can have an audibly-detectable improvement on sound, why are allowances never made for the possibility of a budget cord outperforming another which happens to cost many times more dollars?

These discussions always seem to centre on the spurious nature of marketing of these, and other similar devices, as if 'marketing' is a concept unknown to the general public. Companies use advertising because the damn stuff works. Anyone who thinks otherwise is ignoring the obvious. If we start from that point, the answer to your dilemma lies in empiricism. If I want to try an item in my system, I arrange with a supplier to try it (Alert: Novel idea coming in!) IN MY SYTEM. CDP, tuner, interconnect, speaker cable, stands, turntable, speakers, you pick the item. If I like it, and I feel that the performance is worth the money, I buy it. If not, I return it to my dealer, who puts it back on his shelf.

Now, I realize that I am a fortunate individual because my local dealer is an unusual specimen, who is too damn close to my house, for the safety of my wallet, because he does loan out items to his customers. Where I want to try something that is purchased online, I seek vendors who have home demonstration programs. Interestingly enough, a lot of cable manufacturers do this, including past and present AK advertisers.

When you talk about suggestibility, what about the skeptic who hears a difference, in spite of long-held beliefs to the contrary? Is that suggestibility operating on a subconscious level, countermanding conscious thought?

 

[Art K.]

I've used several brands in the same system and most sounded enough different that with some coaching (describing the sounds to listen for) even my wife could tell the difference and even identify the brand. No science in that just good old fashioned critical listening with just a bit of training.

 

[mhardy6647]

I've used several brands in the same system and most sounded enough different that with some coaching (describing the sounds to listen for) even my wife could tell the difference and even identify the brand. No science in that just good old fashioned critical listening with just a bit of training.

Actually that is science. Objective hypothesis testing is at the core of the scientific method.

Based on your description (and with a little inference on my part which is easily confirmed or refuted) you and your wife conducted a "single-blind study". If she "could tell the difference and even identify the brand", I infer that you knew which brand was installed... and that she didn't. If she could reliably (i.e., by a simple statistical test) correlate aquality of sound with a cable type; the single-blind test was, for lack of a better term, successful. The theoretical objection to a single-blind test is that you, by not being blinded to which cable was being auditioned, might deliberately or accidentally give cues to the listener that could influence her choice. Thus the preference for double-blinding in controlled (clinical, e.g.) studies.

The crux of the biscuit, as FZ would have put it, seems to be "Can different power cords correlate with qualitatively different sonics in real-world hifi systems?" The answer is often if not always "yes".

FWIW (and not in response to any post to this thread, as this statement hasn't been made, nor even implied), I think of the "if you cannot hear it, your system isn't resolving enough" argument as fairly specious; it's the "Emperor's new clothes", hifi version.

 

[dnewma04]

Very nice post, Ernie. I can't speak for others (and I probably don't speak for many with the viewpoints that I hold) but in regards to the points you raise about suggestibility, my personal experience has often resulted in hearing audible differences in things that I may not have expected to hear differences. Where I differ from many in both groups that participate in these sort of discussions is this: When I hear a difference, in the back of mind, I am conscious that differences I am hearing may not be "real" and could very well be psychologically driven, but instead of dismissing them, I try to understand why I may be hearing them. I don't point to some double blind test performed by someone back in 1970 and blanketly dismiss the differences as BS. When I can't come up with an explanation, I have a few questions I need to ask myself. First, is the difference for the better (regardless of states of reality)? If it is for the better, is the differences worth the price of admission and as a followup to that question, is it something I could forget/live without?

I suppose for me, I'll never be fully in the "trust my ears" crowd because I understand that psychological factors can play as big of a role in what I hear as the physical factors that are going on and can be measured. Not only that, but my mind is too curious to allow myself to just run with what my ears tell me without trying to find some validation, which is probably a character flaw on my part. That being said, I'm even less interested in being in the crowd that dismiss those psychological factors as being something less than real.

What I find increasingly frustrating and one of the reasons I don't visit this forum very often is that is an inherent dichotomy that will likely never be bridged. We have one side that simply trusts their ears and naturally, have no inclination to figure out why the differences may or may not exist. This group also takes serious offense to anyone suggesting that the differences are "in their head". We have a second side of "scientists" who are entirely too dismissive of the reality of psychology and also from a more stringent scientific view, too easily just fall back to "[insert random engineer] proved that power cords didn't sound different in 1914! LOOOOK at this link and learn!"

Unfortunately, I feel like the only solution is (what seems to me to be) the half-assed way out where you just say listen to what makes you happy. If you tried out a power cord and it made a change to you that was pleasing and you'd be less happy without it, I'd be a total jackass to say that you shouldn't keep that power cord. On the other side of the coin, if those differences aren't a reality for someone else, I'd also be a jackass to try to claim they should have heard those differences or that their system must not be good enough to have perceived them. There are days when I sit in my chair listening to a record or a CD and it sounds amazing and other days with the same record/CD playing through the same equipment in the same room, at the same time, and I find I don't like it one bit. I can only guess that my mind is in charge and with a gigantic head like mine, my mind has to be pretty powerful.

 

[petehall347]

beware with the copper at a very high price your cables are becoming thinner so much so they can barely cope with the current .its a fact here in the uk not sure over there but i suspect its the same ? just check a modern cars wiring not that cars are the question here but am pretty sure everything concerning copper is the same

 

[petehall347]

on another thought it is whatever works best for you it would be pretty boring if everyone was clones of each other

 

[dnewma04]

I don't know, I think a few clones of me would be pretty exciting. Not sure if the rest of you would agree, though, and I suppose I would hate myself more than I already do.

 

[dumptruck]

I suppose for me, I'll never be fully in the "trust my ears" crowd...

I'm such a skeptical cheapskate that I have no problem trusting my ears to do no worse than cheat me out of miniscule improvements I didn't want to hear. I am pretty sure expensive power cords are not one of those. I would be perfectly happy to proven wrong, but I'm not about to spend the money to try to prove myself wrong. I'll put that cash in the speaker budget, thank you very much.

 

[luvvinvinyl]

At the risk of threadcrapping, why doesn't the argument extend to speakers. After all, everybody acknowledges that speakers are voiced differently, and that the FR curves bear this out. Why, then, are subjective responses so different? I have heard speakers, some very expensive, that test wonderfully, but hurt my ears. Others look dismal, on paper, but commanded my entire attention, when playing music.

Are power cords any different, notwithstanding the scale of variability?

Dave, I hold the same reasoning as you, but, at some point, it seemed a Quixotic endeavour to find the solution. I finally succumbed to accepting the fact that, like you, I am a unique individual, and that acceptance requires me to make allowances in my psychological response to music playback, and everything else, for that matter. I try to ignore the +/- 3σ results, and, to use a colloquialism, "go with what works". I'm a big believer in empiricism, but only insofar as my personal set of results is concerned. I don't pretend to tell others that this or that is the only way to go. I can only relate that widget A works for me, in the context of my room/system/mood. Hell, I have a friend who can't stand to listen to my stereo, nor me, his. It doesn't make either of us 'bad people', nor uninformed, nor less than critical listeners. What it does mean is that there is almost no common ground between the two system/listener combinations.

It seems to me that the two camps even exist only because one side, the other, or both, attempt to impose their will, on the other, simply because each cannot avoid transplanting their own selves into the circumstances of the other. Their knowledge colours their opinion, just like ours does. When either side, or both, fails to respect the individuality of those who make up the other side, dogma becomes the order of the day, and people try to impose their will on the other. "I'm right, you're wrong, and the science bears me out!" "I don't care what your graphs say, there is no way that I'm wrong about what I hear". Each side can shout that at the other, until both are blue in the face, and all that changes is the level of animosity.

 

[shelly_d]

:yes:

Fixed.

Thanks!

Shelly_D

 

[luvvinvinyl]

By the way, in reference to my second post, I, and a friend, for whose judgement I have infinte respect, experienced a 'shoot-out' of two power cables, one costing $40, and the other, $700. The differences were NOT subtle. The winner is in my system, attached to my cdp, where it has since held off other pretenders to its throne.

 

[luvvinvinyl]

Oh, I forgot to mention, the $40 cord was the hands-down winner, for both of us.

Not even close. Why? I can't tell you, because I don't know. Frankly, I'm past being curious about it. I just enjoy the results.

 

[luvvinvinyl]

I don't know, I think a few clones of me would be pretty exciting. Not sure if the rest of you would agree, though, and I suppose I would hate myself more than I already do.

Could be worse...




...could be me.