What's the best way to burn in a power cord?

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Hadn't read Grey's message when I posted. Grey you make some good points about being open to new ideas, but you take your analogy too far.

What really pushed my buttons is when someone takes something that has a small hint of reality and then uses it to justify all kinds of unsupportable positions. The problem is not that someone is saying Jupitor has moons, but rather they are saying that Jupitor tastes like a banana split.

I don' t doubt for a minute that this guy absolutely believes that burning in a power cord makes an audible difference in his system. But so what, there are plenty of people who believe the Earth is flat and that's the reason why they believe the space missions to the moon were faked (they had to be fakes, they kept showing pictures of a round Earth, now if they had just once showed a flat Earth through that porthole we'd could agree to get along).

The big difference between Galileo and these "cable guys" is that all Galileo had to do was say "lookie through here" and his doubters had to admit that he might be on to something. The "cable guys" can't seem to do that (at least not without a month of burn in first, I wonder if that is so you will forget what your system sounded like before you dropped a grand or two on a line cord).

Human perception is a very slippery thing. I quote:

"A University of Washington study has shown that our memories of past events are incredibly malleable and highly unreliable. At a presentation of the findings at Glasgow University it was noted that: "In some sense, life is a continual memory alteration experiment where memories are continually shaped by new incoming information." To prove this hypothesis Jacquie Pickrell, a doctoral candidate in psychology, and professor of psychology Elizabeth Loftus, presented a group with an advert showing Bugs Bunny shaking hands with visitors to Disney World. Later 30 per cent of the viewers also remembered meeting Bugs Bunny when they had visited Disney World when they were children. As anyone with any knowledge of animation knows Bugs Bunny is not a Disney character and has never appeared in a Disney theme park. From her research Pickrell concluded: "You can truly implant a memory for an entire event that never happened." Loftus said she felt that this small study makes us question such factors as: "When will people take a detail and attach it to some other memory? How do we bind pieces of experience together? When will you take a piece of experience that kind of floats around in the mind and attach it to another experience? Why and when does that happen?" This work shows that people can be convinced (some would say tricked) into believing they experienced something in childhood or the past that did not really happen. For advertisers and marketing companies this can be a very powerful tool. For example, Stewart's, a root beer manufacturer, highlighted how people can use new information to reshape their autobiographical memories, when they put 'old fashioned' and 'original' labels on their bottles. Adults then remembered drinking the product as children, yet this drink was not bottled until the 1990s. "

http://faculty.washington.edu/eloftus/

And you want me to believe you can "remember" what a system sounded like from before a month of "burn in". There is a really simple experiment you can do yourself, right now in your own home to demonstrate this to yourself. Go over to your sound system and turn one of the tone control knobs a quarter turn from flat (I don't care which one). Listen to music though the system like this for a while (a half hour ought to be plenty), then turn the tone control back to the flat position. Your system will sound strange and out of tonal balance for a while even though it is back in the "flat" setting.

Phil
 
Joseph Cohen said:
"It may shield from RF picked up by the cord, but you have to consider that mains lines rarely have transients less than several volts, and often have more noise than this. The mV-or-less induced RF noise will be swamped by the pre-existing noise."

Point well taken. Of course the power supply should handle these "big" spikes etc. But I wouldn't underestimate the noise picked up by the power cord.

No no no, you CAN and MUST underestimate it... as it was said, RF noise will be picked by any unshiedled wire , but it will be several (hundreds) of orders of magnitude less than the distortion and noise on a normal power line (%5 to %10 is not uncommon, sadly). Now, if the power supply of your amp has trouble rejecting that, well, you'll need much more than a new power cable. But yet, if RF noise bothers you, you could build your own shielded cord (with an RF filter if you want) for MUCH less than the $150-200 charged for them...

And also, why would you want to "burn in" the cord anyway? The burn-in myth of cables is nonsense; and as for cables having effect on the audio quality, for interconnects i can beleive it (to a certain degree), but a power cord...

Really, check Rod Elliot's articles on these subjetcs. There's a lot of good info there.... cables are not magic.
 
Not all RFI is discernable as audible noise in the sense that you are hearing an am radio station in the background. Noise from my point of view, exists in ways that clearly affect the behavior of a system. But usually you don't notice its presence until you have removed a portion of it, and you can hear that the system is cleaner and clearer.

I frankly don't give a rats *** whether it's acceptable to be subjective around these parts or not. I'm going to tell it as I see it, and my personal experience, in rewiring dozens of systems has led me to believe that this approach has merit. Look, I would be thrilled if I could go to the hardware store and for $1.98 buy a lamp cord that would yield glorious sound. Some purveyors of high end cable have come close to doing just that - They've taken off the shelf stuff and repackaged it and charged big bucks for it. Is that criminal? Yes, probably. Others have dedicated hours days and years to perfecting cables that make astonishing improvements in all parameters of a system. If you haven't heard it, then sorry for you.

When you get down to it, the explanation of what makes it work doesn't matter. What counts is that in some certain cables it works and works unmistakeably.

Forgetting what I heard, being deluded by mass hysteria...Give me a break. Either you trust your ears or you don't.
 
Not all RFI is discernable as audible noise in the sense that you are hearing an am radio station in the background. Noise from my point of view, exists in ways that clearly affect the behavior of a system. But usually you don't notice its presence until you have removed a portion of it, and you can hear that the system is cleaner and clearer.

I frankly don't give a rats *** whether it's acceptable to be subjective around these parts or not. I'm going to tell it as I see it, and my personal experience, in rewiring dozens of systems has led me to believe that this approach has merit. Look, I would be thrilled if I could go to the hardware store and for $1.98 buy a lamp cord that would yield glorious sound. Some purveyors of high end cable have come close to doing just that - They've taken off the shelf stuff and repackaged it and charged big bucks for it. Is that criminal? Yes, probably. Others have dedicated hours days and years to perfecting cables that make astonishing improvements in all parameters of a system. If you haven't heard it, then sorry for you.

When you get down to it, the explanation of what makes it work doesn't matter. What counts is that in some certain cables it works and works unmistakeably.

Forgetting what I heard, being deluded by mass hysteria...Give me a break. Either you trust your ears or you don't.
 
Apologies to AudioFreak

First, my apologies to AudioFreak, I discovered my error after I posted. So, sorry AudioFreak. Now, on to Joseph Cohen (The person who actually started this thread) if you're hearing a difference, fine, great, happy for you. Now, lets back up for a second, as Grey brought up a valid point, what's the rest of your system? Personally, I know my system is nowhere near the level of quite a few people here, and I know that changing the power cord won't do a thing to the sound on my system. Maybe for your system it will, its also possible that you've got a lot of RF interference that a lot of us don't have. But I still fail to see what 'Burning in' is going to do for a power cord. Do you think there's a change going on inside the power cord? (I'm not asking this to be a jerk, I'm honestly curious) If so, what would this be? I'm not an electrical engineer, or anything like that, so my knowledge of such things is low, and there may, actually be something that goes on that I didn't know about. Again, this isn't to say you're wrong, an idiot or anything like that, I'm just trying to understand where you're coming from.
 
Dear Joseph Cohan,

I think most of the faithfuls to this forum (i.e. the DIY diehards) are believers that a 2m power cord does not make a lot of difference to the "cleaniness" of the sound from the apmlifier, be it "burned-in" or otherwise.

In fact, from your response earlier I have this feeling that you may have reviewed Mr. Rod Elliott's artile on this subject and probably understood his viewpoint.

Once upon a time, I had been led to believe power cords and other cables made of OFC or other superior material would have a big difference on the quality of sound. After you have opened some of the expensive HiFi equipment and loudspeakers you find the wiring is no different from you local electronics parts supplier put on their shelf; and it ain't US$500 a metre stuff. So why are we paying megabuck for an incomplete hook up of the best cable? How about the copper trace on the amplifier's circuit board? How about the wire in the transformer? The list just goes on.

I agree electronics components may need some burn-in time, to allow the semiconductors to flex a few times into its optium operating region, but a burned-in power cord does not make current flow better. With my experience as an electrical engineer, I have only seen cables carry less current (due to oxidation) in time.

I agree with Gey Rollins that we should keep an open mind to new concepts, and I will try a little experiment comparing expensive cables vs. 300A cables used in some of the electrical installations I have access to. I may post the results if I could persuade my "golden ears" friends to participate.

In reality, the process of burning-in would have little effect on the noise level. I think the design, i.e., the characteristic impedance (capacitance, inductance and resistance) would impact the quality of sound. The effetiveness of shielding would minimise RF interference. But not burning-in.

Grey / Joseph, any comments?
 
Joseph,
Accept my assurances that not everyone thinks you're delusional. I trust my hearing and keep it tuned up at regular concerts. Last Saturday night the program included Brahms's second and Tchaikovsky's violin concerto. I wish it was possible to find good acoustic jazz hereabouts, but that's simply not in the cards.
As I'm sure you've noticed, there are people here who would rather participate in arm chair theorizing than go to concerts, educate their hearing, come home and recognize that their system is not what they thought it was. It's much easier for them to belittle someone who doesn't believe in their religion.
Unfortunately, the prices that companies charge for cables make them a rather easy target for ridicule. Once you get started on,"They want <i>how</i> much for those cables?" the next comment invariably comes as,"There's no cable in the world that could make enough difference to be worth that kind of money," followed by,"Huh...probably doesn't make any difference, anyway...they're just getting rich off of gullible people." At any rate, you can see how the progression goes, as it's not long before they're saying that clearly the cables don't make any difference at all.
Well of course they don't--no one bought them to give them a try. It was easier to criticize (which the cable companies left themselves open to with their pricing strategies). And, in this case, I think it's safe to say that some of these folks' systems would not benefit from better cables, anyway.
I don't believe in magic, but that doesn't mean that we currently have adequate theories for everything that goes on in a stereo (and we won't get there if people keep saying that there's nothing to theorize about). For those who simply must put 'logic' before observation, the only theory I've heard yet that makes even a vague sort of sense is that running a current through a wire provides electrons which settle into electron voids in the insulator, allowing the insulator to become a better insulator. Note that I am not endorsing this theory, I'm just reporting it. I like it somewhat better than the theory about diode effects being at the root of sound differences in wires, but not so much that I'm going to hang my hat on it. As yet, it seems to have the field to itself; I prefer to have two or more theories so as to be able to compare them, as the first one out of the gate isn't necessarily the one who wins the race.
Joseph, I confess that I don't bother to burn things in separately, I just put them into service and let them go as they will. In most cases, 50 to 100 hours will do the trick.
The point that Phil rather misses, perhaps because he isn't familiar with what happened to Galileo, is that Galileo's contemporaries <i>refused to look</i>. Why? Because they were already certain that there was nothing there to see. Arm chair theorists, you see (not unlike certain people today who'd rather not take the trouble to listen to cables on a good system). The few that did take the trouble to look and were convinced by what they saw were ridiculed themselves. Galileo himself was placed under house arrest--tortured by some accounts, though others say not--excommunicated, and generally treated poorly. It took until ten or fifteen years ago for the Catholic church to forgive him (grudgingly) for being right. A bit late, I'd say, as the poor man's been dead for a year or two. Note that the list of things that high end people have been 'proved' right about is lengthy: audibility of passive components, absolute phase, extended frequency response, etc. etc. etc. Each and every one of those points was ridiculed in its turn, yet turned out to be right in the long run. If I were a betting man, I'd side with the winning side, and I'll give you a hint--it ain't the arm chair theorists' side.
Cranking tone controls doesn't make a system sound anything other than grotesque. Turning them back to a neutral position is like swatting an annoying mosquito. A relief. I find it difficult to see how anyone who is familiar with the sound of live music would find this to be a convincing demonstration of anything other than the sound of tone controls.
For those who would rather taste their stereos, I wish them well. I'd rather listen to mine.

Grey
 
Fields and charges are very complicated matters, alot of thing happen over time

<a href="http://www.execpc.com/~endlr/Reliability/Space_Charge/space_charge.html">"Space Charge"</a> <font color="#800000" face="ms comic sans"> is charge in the dielectric, electrons, protons, and ions, that is moved around by the applied voltage.  Charge tends to build up at "discontinuities" in the dielectric, such as the dielectric-electrode interface in film capacitors, at the grain boundaries in crystalline dielectrics, and at various molecular sites simply called "charge traps".  Space charge is a major factor in dielectric behavior, such as leakage, high-voltage reliability, and dissipation factor vs. frequency and vs. temperature.  Its role in dielectric aging is still the subject of research.  Researchers have shown a special interest in cross-linked polyethylene (XLPE) because of its widespread use as a high-voltage insulation in power transmission, but work is also being done with polyethylene napthalate, PMMA, silicon dioxide, and other common dielectrics.  Space charge has been extensively studied for many years, but I can´t remember any books or journal articles specifically relating space charge phenomena to capacitor behavior.  It may be that capacitor people and dielectric theorists don´t talk to each other much.
<snip>
Space charge behavior in dielectrics is still being actively studied, and some of the above is still not understood in detail.
</font>
 
Here's something I wrote for a line of cables I was at one time importing:

"Correctly designed cable is the primary and most critical means of insuring the proper delivery of the audio signal from source to loudspeakers. The general misconception is that audio cables are like hoses with the signal traveling inside them. In fact the flow of electrons within conductors is measured at a few meters per second, while the signal itself travels on the energy of the electromagnetic force surrounding the conductors at the speed of light. For this signal flow to be perfect and unimpeded it is necessary that the electromagnetic fields surrounding the conductors retain their symmetry, which is distorted by EMI, RFI and high frequency digital pulses and especially by stray capacitance which arises as a result of signal and current that runs on the shield and throughout all the cable's materials. Stray capacitance is the single greatest cause of coloration and distortion in audio cables."

So from my point of view we are already into quantum physics when we attempt to describe the forces at work in the behavior of signal transmission. This goes way beyond capacitance, inductance and resistance and into areas that are mostly beyond the capabilities of our most sophisticated measuring instruments.:cool:
 
Joseph

If you are so knowledgeable about cables, why did you need to ask your original question about the best way of burning-in a power cable? Would it perhaps have anything to do with the fact that, as an importer/supplier, you have a vested interest in raising the profile of these high-profit-margin products?

From your write-up on cables, would I be correct in assuming that interconnects and speaker cables have more effect on sound quality than an amplifier? Does the stray capacitance really arise from the signal and current that runs on the shield (I always thought it was an intrinsic characteristic of the cable design and materials)? Also, does the stray capacitance in a cable have more effect than a poorly-made or corroded connection?

I'm sorry, but I just don't buy it.

Geoff
 
The good part of having Elders around here..

Is that we stand a chance to keep the smoke blown/*** ratio down to a reasonable level. Powercords? Well, yeah if you are using one of killerwatts amps on lamp zip cord... and your lights dim to the beat, you should investigate improving your entire mains supply.

Never spend more than 1/20th of your entire system cost on interconnects. Hey, if you have blown 10K on your stereo, $500 on cables may make sense. But you can't gold plate that turd you bought on sale at Walmart and expect sonic improvement.

I love the new optical interconnects. Say what? Someone is really gonna have to explain this one to me. I blow big signals down miles of fiber. No problem. Them photons are the same at the other end. So why is this three foot cord so hard?
 
Geoff,

I am longer importing or selling any cables, nor do I claim to be an expert. I did have long extended conversations with the designer which led to the above blurb.

I probably could have phrased the burn in question a little differently to read: What are the latest methods people are using? I should have asked the question at audioasylum and probably will, but I'm enjoying the give and take here.

I would never say that cables have a greater effect on sound than a well built amplifer, but I would say that you will hear the optimum behavior of that amp when used in conjunction with properly designed cables.

I would say that stray capacitance arises from the interaction of signal, current and materials.

Wherever you have a metal to metal connection in a system, you have stray capacitance - whether corroded or not.
 
Joseph

OK, I will accept that you don't have a vested interest (or at least not much of one) and I agree that the Asylum would have been a far better place to raise this question if you wanted like-minded people to agree with you.

I do not wish to drag this thread out any further than need be, but you seem to be contradicting yourself in consecutive posts. Which do you really believe; is it "Correctly designed cable is the primary and most critical means of insuring the proper delivery of the audio signal from source to loudspeakers" or "I would never say that cables have a greater effect on sound than a well built amplifer......"?

Also, before you visit the Asylum, could I respectfully suggest that in your references to "by stray capacitance which arises as a result of signal and current that runs on the shield" and "I would say that stray capacitance arises from the interaction of signal, current and materials." you replace 'stray capacitance' with 'the effects of stray capacitance'. By doing so you won't get pedants like me querying what you mean.

Geoff
 
quote: Which do you really believe; is it "Correctly designed cable is the primary and most critical means of insuring the proper delivery of the audio signal from source to loudspeakers" or "I would never say that cables have a greater effect on sound than a well built amplifer......"?



The two statements are not contradictory. (It goes without saying that the amplifier is required to "deliver" the signal to the speaker, but in this context, the implied meaning is how you get the signal from one box to the next to the speaker.)

quote: "I would say that stray capacitance arises from the interaction of signal, current and materials." you replace 'stray capacitance' with 'the effects of stray capacitance'. By doing so you won't get pedants like me querying what you mean.

Good point.
 
Joseph

I understand where you are coming from now. It was just that the "proper delivery of the audio signal from source to loudspeakers" appeared to rule out the amplifier in the middle. That's the trouble of semantics. You use the term distortion to include induced noise whereas I would maintain that a cable does not distort the signal since a THD measurement before and after the cable will reveal no difference. A measurement of the S/N ratio is another matter!

Geoff
 
GRollins said:
Cranking tone controls doesn't make a system sound anything other than grotesque. Turning them back to a neutral position is like swatting an annoying mosquito. A relief. I find it difficult to see how anyone who is familiar with the sound of live music would find this to be a convincing demonstration of anything other than the sound of tone controls.
Grey

Grey, I have some working experiance with mixing live sound. I am not gods gift to mixing, but I do get out and listen to live music a couple of times a month (mostly acoustic sets, occasional R&R).

It's interesting the way you responded to my experiment suggestion. On the one had you condem armchair theorist who ignore real experiances and then you turn around and dismiss the experiment without trying it. Kind of inconsistant isn't it. Try it, the results may surprise you.

Besides, the point of the experiment isn't if tone controls are good or bad, rather it is about how easy it is for our senses to mislead us. I don't trust the results from a piece of test equipment until I understand it's limitations. I try to treat my own perceptions the same way. After all if I don't understand the limitations of my own perceptions then I can be fooled by someone who does. A good example of this is the volume dependant frequency response of our hearing.

P.S. Galileo didn't have any problem getting people to believe in the moons of Jupitor, that's what made him famous in the first place. He got in trouble for claiming the Earth wasn't the center of the Universe.

Phil
 
Joseph Cohen said:
nor do I claim to be an expert.
...
Wherever you have a metal to metal connection in a system, you have stray capacitance - whether corroded or not.

I'm glad you don't claim to be an expert. Capacitance has nothing to do with "metal to metal" connections and exists even in solid unbroken cables. It happens whenever you have two conductors in proximity with a dielectric (air will work in a pinch) between them. Corrosion doesn't come into play at all (unless it's so bad it breaks the wire or changes the chemical makeup of the dielectric).

I will certainly agree that capacitance in audio cables attenuates high frequencies in a signal. But what has that got to do with power cords? We aren't passing audio signals through the line cord, we're just topping off the main filter caps as needed.

If you have ever looked at the current pulses running around inside the power supply of a working power amp you would realise that the noise coming in through the line cord has about the same effect as peeing in the ocean. Did you know that the diodes in your power supply generate RF? And not a small amount either. I wasn't kidding about needing an RFI filter in the AC input to make amps pass FCC emmisions testing.

Your post is a perfect example of the pseudo-engineering reasoning I keep hearing from "subjectivist" . I liked it a lot better when you said "I have heard changes when I do stuff and I like it". That is perfectly legitimate, it is very possible that you have really improved things with what you are doing. It is also possible you have changed how something looks, without really doing anything meaningfull to the sound.

In real life, I am an electrical engineer and I design commercial signal processing gear for Mettler-Toledo Inc (the lab balance people). I can come up with some very impressive sounding mumbo-jumbo from other disciplines in support of my ideas if you like, but the reality is they don't have anything to do with what we are talking about so I won't waste your time with it. Please do me the same favor.

I don't design audio gear for a living (at least not in a big way yet) and I know I have a lot to learn about good audio design practices (that's the reason I'm here, I love this stuff and there are people on this site who have a clue). But I do understand fundamental physics and electronics principles and I can figure out pretty quickly when someone else doesn't.

Best Regards,

Phil Ouellette
 
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