Cable burn-in: Is it real or imagined?

[dmnc02]

After I started burning in my cables this issue completely went away.

Again, that is a very clean double-blind test that should be food for thought for any objectivist doubting cable burn-in.

 

[dmnc02]

This should be an absolute snap then,
http://archive.randi.org/site/index...ake-withdrawls-from-pear-cable-challenge.html
Keith

It is amusing (and telling) that the people who stall every thread insisting on the absolute necessity of blind tests are then unwilling to accept the results of such tests. Talk about cognitive biases

 

[Robh3606]

The first is a double-blind test of cable burn-in (assuming customers did not know whether the cables they received had been burned-in or not), the second is a sighted test.

That is not double blind test. Double blind is when all parties don't know. So Dave and his customers would have no knowledge of which cables were or were not burned in.

Rob

 

[dmnc02]

That is not double blind test. Double blind is when all parties don't know. So Dave and his customers would have no knowledge of which cables were or were not burned in.

Rob

Double-blind tests are meant to eliminate the observer-expectancy bias. You might want to read about the Kluge Hans horse in order to understand this bias. The experiment run by DaveC was immune to this bias.

Another way to look at this is that in this experiment the customer was both the tester and the subject.

Edit: To be clear, what I am assuming above is that, after he started burning-in his cables before shipping, Dave followed the normal manufacturer's behavior, i.e., shipped the cables to his customers and was not otherwise in contact with them during the trial period.

 

[thedudeabides]

Differences like these should be readily apparent, so the listener has little to no excuse for guessing wrong.

IMO, depends on what type of music you are listening to on what system and your familiarity with the inherent sound of the system and the recording. And how long the "snippet" is. And what the loudness level is, etc....................

As I said before, my feeling is that these type tests are like watching the "trailer" for a new movie and making a judgement on the "quality" of the film versus watching the entire movie and providing comments.

 

[Occam]

A second person must change the cables.

The test must be run numerous times. The person changing the cables must also LIE TO YOU about changing the cables part of the time--saying they changed them when they actually did NOT change them and seeing if you find a difference.

A reasonable single blind test (the admin knows which cable is in situ) housed in the right church, but the wrong pews.....

You MUST MUST guess correctly at least four out of five times because adjectives usually used in expressing the differences are terms like "greatly improved soundstage", "greater depth", much sweeter highs and midrange", better controlled bass", etc.

Its not your place to determine which particular pews we sit at, within your church. A subjective decision on what constitutes 'greatly improved soundstage' or 'much sweeter highs and midrange' are doomed,IMO, in a morass of subjective vagueness.
Now if one were to take a subjective evaluation that can be expressed objectively , you've got a chance. Something like image height (one can point or align a inclimoneter). I use Holly Cole's 'I can see clearly now' to determine preferred cable directionality, but DaveC has asserted that cable directionality is simply imposed via dielectric/insulation forming, in other words, with break in. This should be quite testable.
Alternatively, one could choose a specific signal that is particularly revealing. Armin used jangling keys, I prefer the sound of a tambourine. Much like obscenity, I can't definitively define the sound of a tambourine, but I know it when I see/hear it.

Differences like these should be readily apparent, so the listener has little to no excuse for guessing wrong.

Balderdash!!! Especially when someone with an obvious agenda determines the metrics. Besides test anxiety, such nebulous metrics that you assert are readily apparent, are by no means apparent. The subject of any listening test, whether single or double blind needs to be trained. It doesn't matter whether Joe Schmuck can pass your tests, what matters is whether anyone can pass a properly constructed empirical test with a specific statistical confidence level.

Personally, as I believe the majority of my cable's break in occurs within a half hour, I don't have a dog in this fight. What I do care about is that properly designed empirical experiments can yield knowledge that leads to improved cables and/or other products.

 

[DaveC]

Hi Paul, directionality is another subject but I'd point out that I don't believe directionality of a cable is formed during break in, rather it's in the atomic structure of the conductor. Also, I use Upocc wire and I do not believe it is directional in the same way as conventionally drawn wire as the crystal structure is already perfect and the manufacturing process is not the same.

 

[DonH50]

Since the signal is alternating, and current forms a loop, how does a directional cable handle normal signaling? I have never understood that premise, although some cables do have terminators that can make them "directional" in the sense that you should not interchange the source and load ends. And the few metallurgy and quantum mechanics classes I had did not indicate any reason for a normal copper, Al, etc. conductor to be directional in its electrical or mechanical properties.

I have torn apart some directional cables, long ago, and discussed their properties with their designers, and they generally alluded to the shield wrap and weave rather than metallurgy itself (some brought up atomic properties but I am not sure either of us really understood what the other was talking about). Since the signal is not static or LTI even the shield wrap argument left me a little cold.

When a cable has changed the sound of a system I have usually been able to pin-point the cause without a whole lot of effort but it is not something I have tried to do in a decade or two. It often had little to do with the cable itself, though in some cases there was clear interaction among cable and the components.

edit: I am not an expert in either quantum mechanics or metallurgy, just know what a typical analog IC designer would know.

 

[Occam]

Hi Paul, directionality is another subject but I'd point out that I don't believe directionality of a cable is formed during break in, rather it's in the atomic structure of the conductor. Also, I use Upocc wire and I do not believe it is directional in the same way as conventionally drawn wire as the crystal structure is already perfect and the manufacturing process is not the same.

http://www.audiocircle.com/index.php?topic=118081.msg1264204#msg1264204

....
@mjosef, ....
Also, interesting on running the DD in the opposite direction as the cables' construction is not directional. So, if you prefer them in the reverse direction you would need to change orientation every few hundred hours of playing time as the dialectric breaks into being run in the opposite direction. What you are hearing is the reaction of the dialectric... I will have to try it out sometime and see....

I see your views on directionality have changed. I do hope that change was prompted by empirical investigation.

 

[Occam]

Don,

Excellent points. You're asking me for an indirect proof of directionality, one of causality. I don't have one. I've got some WAGs (wild assed guesses), but they hardly rise to the level of a hypothesis, let alone a theory. I don't like blowing smoke up.... All I have are empirical experiments that do verify this, leastwise to Gary's criteria.
Yes, I've verified this on my own stp ICs, and it doesn't matter where I connect the telescoping shield, source or load end. I'll even assert that a SOOW triad powercord can show (height) directionality. If you'll listen to at least a 16:44 file of that Holly Cole I can see clearly now, and you do hear her voice at a 30 degree+ elevation, (or height perception on the Stereophile 'Up and Over" track) I'll send you a pair of powercords, exactly alike, save for the one cord's direction being reversed from the other's. You can do your own empirical investigation, if you'd like.

Regards,
Paul

 

[DaveC]

http://www.audiocircle.com/index.php?topic=118081.msg1264204#msg1264204


I see your views on directionality have changed. I do hope that change was prompted by empirical investigation.

Yes, but I also think there is more than one mechanism at work... and to partially answer Don's question... conventional wire that is drawn through a die will have it's crystal boundaries arranged in a chevron pattern while UPOCC wire has no crystal boundaries. I'd guess that this is what causes directionality in a wire, it's due to the asymmetrical crystal structure of the conductor. I also think there is a rearrangement or polarization of dielectric when burn-in happens, which is what I believe was happening in mjosef's case you quoted above. I was searching for more opinions and I did find other people who think it's best to switch the direction of their cables regularly. I have tried this and there may be a minor difference but for me it falls into the category of changes that are too minor to worry about.

Don, most of the time shielded cables have the shield attached at the sending end only, often this is the only reason a direction is indicated on the cable. Also, while the signal may be alternating between + and - voltage with reference to ground there is also a wave propagation that IS directional... after all the signal is generated by the source and travels from the source to the speakers. There is a difference between the movement of electrons (which is slow) and the propagation of the signal as a wave that happens near the speed of light.

 

[BlueFox]

First, cables do make a major difference, and audible burn-in does occur, at least with good cables. Here is my hypothesis.

At the atomic level, the atoms in the conductor align over time to provide the most efficient path for conduction. Since an audio cable is always doing the same task, such as deliver AC or transport a signal, the cable optimizes for that task. Better cables will provide better optimization, and it is audible. Assuming the gear, and your ears, are up to the task.

That is my hypothesis, and I am sticking with it.

 

[Occam]

Yes, but I also think there is more than one mechanism at work... and to partially answer Don's question... conventional wire that is drawn through a die will have it's crystal boundaries arranged in a chevron pattern while UPOCC wire has no crystal boundaries. I'd guess that this is what causes directionality in a wire, it's due to the asymmetrical crystal structure of the conductor. I also think there is a rearrangement or polarization of dielectric when burn-in happens, which is what I believe was happening in mjosef's case you quoted above.

My bolding above What you or I think, believe or guess is meaningless unless verifiable empirically.

I was searching for more opinions and I did find other people who think it's best to switch the direction of their cables regularly. I have tried this and there may be a minor difference but for me it falls into the category of changes that are too minor to worry about.

Opinions are like bodily orifices, everyone has many....
I certainly agree that flipping a cable around, to do whatever dielectric voodoo doesn't do squat.

Don, most of the time shielded cables have the shield attached at the sending end only, often this is the only reason a direction is indicated on the cable. Also, while the signal may be alternating between + and - voltage with reference to ground there is also a wave propagation that IS directional... after all the signal is generated by the source and travels from the source to the speakers. There is a difference between the movement of electrons (which is slow) and the propagation of the signal as a wave that happens near the speed of light.

Or one could check the directionality (if any) of a telescoping stp (shielded twist pair) cable by going to the extreme effort a building 2 pairs of cables and testing.

 

[DonH50]

Thanks all for the responses.

I was not considering STP nor other balanced (e.g. XLR) cables, only standard RCA interconnects. The shield connection is a valid point though perhaps more related to EMI/RFI shielding than audible benefits. IMO! As for group delay, or dispersion, loss tangent, skin effect, and other RF parameters, I am very familiar with those but IME/IMO they just do not apply at audio frequencies. (N.B. I am talking about audio interconnects, not digital links.) Typical cable propagation is ~40 % to 90+ % the speed of light which is far above the speed of sound, and dispersion at audio is insignificant if not unmeasurable in standard cables.

I am unaware of any dielectric realignment related to directionality. The dielectric, assuming it is not dry air or inert gas (used in waveguides and some high-power and/or very high resolution RF transmission cables), does include various defects and charge traps that adds noise, hysteresis, and take a finite amount of time (but very small, certainly not hours) to fill. There are also thermal effects and such, but I just can't see these things being an issue at audio. Clearly I could be (some will say "am") wrong, and I will note I have had to deal with all these effects at various times in my career. I will say charge traps present an interesting line of thought since they can add noise, can take time to fill and then can release and re-fill at fairly low rates (i.e. in the audio frequency range), and those and other dielectric parameters are influenced by things like voltage, signal frequency, and temperature. the effects are very similar to those seen in various capacitor studies through the years (much the same causes and effects). Some low-noise cables we ran a D.C. current through to keep them biased. This was for systems when we were looking well below -100 dBc (in some cases to the thermal noise floor around -140 dBc or even below, and some were cryogenic -- N/77 K or He/4 K). Again with normal audio signals and impedances it's hard for me to believe such things are audible, but clearly many feel otherwise, and I have not applied that sort of testing to audio cables in many years.

Atomic alignment of conductors is the subject of various papers I am far too lazy to look up (check out IEEE and similar organizations). Discontinuities and defects in the conductors can cause measurable artifacts, but again (unless unreasonably large) these are usually seen at higher frequencies and lower noise floors (by several orders of magnitude) than an audio system.

As an IC designer I have had to deal with various material alignments, from grown "pure" crystalline structures, to sputtered metal which creates as chaotic a mess as the name implies.

I would be interested to try some high-end (directional or not) cables but frankly have shied away because (a) I am biased to the other (skeptic) side, (b) do not have funds for those cables and do not wish to take on trial something I know I will not keep (seems dishonest to me), and (c) no longer have either the million dollars or so worth of low-frequency test equipment I had years back nor my double-blind test system. I also know based upon hard experience that if I hear no difference it will not matter to those who do, they'll denigrate my ears, my system, a thousand other things. If I want to be told what an idiot I am I'll talk to my teens. The last few times I have participated in such tests I have kept the results private between me and the people kind enough to submit their products for me to try. If the results were favorable, they were free to publish; if not, well, "if you can't say anything nice..." and I was OK with that.

Onwards - Don

 

[Robh3606]

Rob,
Can you specify which known parameters you are thinking about? As far as I know cable sound has never been correlated with a specific measurement.

Hello Micro

Well that's the point really. What's changing?? You can measure L/R/C or just measure frequency response and phase, dielectric properties and so on. If you don't do any measurements how can you begin to understand which ones might be relevant??

Rob

 

[FrantzM]

Yes, but I also think there is more than one mechanism at work... and to partially answer Don's question... conventional wire that is drawn through a die will have it's crystal boundaries arranged in a chevron pattern while UPOCC wire has no crystal boundaries. I'd guess that this is what causes directionality in a wire, it's due to the asymmetrical crystal structure of the conductor. I also think there is a rearrangement or polarization of dielectric when burn-in happens, which is what I believe was happening in mjosef's case you quoted above. I was searching for more opinions and I did find other people who think it's best to switch the direction of their cables regularly. I have tried this and there may be a minor difference but for me it falls into the category of changes that are too minor to worry about.

Don, most of the time shielded cables have the shield attached at the sending end only, often this is the only reason a direction is indicated on the cable. Also, while the signal may be alternating between + and - voltage with reference to ground there is also a wave propagation that IS directional... after all the signal is generated by the source and travels from the source to the speakers. There is a difference between the movement of electrons (which is slow) and the propagation of the signal as a wave that happens near the speed of light.

I am an EE. I know absolutely nothing about metallurgy. I am trying to get an handle on your post. What do you mean by , I am re-quoting you ,

UPOCC wire has no crystal boundaries

??

Additionally , how can we talk about directionality in the case of an alternating current which is after all what the signal is? What is the direction of the signal flow if the signal is alternating? Can someone explan that to me? So let's drop the directionality issue? Let'sfocus on the subject of this debate, a question posed in the OP: Cable burn-in: Is it real or imagined??

The subject has strayed very far from the original post . Many have gotten very defensive about their perceptions being questioned and skeptical views have been dismissed or sneered at. To re-center the debate, I think I and ( i dare to think ) most of the skeptics in this thread are not debating perceptions of cable changing the sound of a given system. Let's leave this for another debate aka food fight . We are discussing the perception change to the sound after a cable has been cooked (thorugh a very particular device doing a number of unexplainable things) or burned-in by just playing music ofr some special signal thourgh it. So far the explanations for such have been tenuous at best and over-reaching would not be ou of place to qualify these.
This question will surely raise the anger of the burn-in believers, I am again asking if anyone feels confident enough to test their ability to identify reliably a burned-in cable from an un-burned, uncooked one?

 

[dmnc02]

I am an EE. I know absolutely nothing about metallurgy. I am trying to get an handle on your post. What do you mean by , I am re-quoting you , ??

Additionally , how can we talk about directionality in the case of an alternating current which is after all what the signal is? What is the direction of the signal flow if the signal is alternating? Can someone explan that to me? So let's drop the directionality issue? Let'sfocus on the subject of this debate, a question posed in the OP: Cable burn-in: Is it real or imagined??

The subject has strayed very far from the original post . Many have gotten very defensive about their perceptions being questioned and skeptical views have been dismissed or sneered at. To re-center the debate, I think I and ( i dare to think ) most of the skeptics in this thread are not debating perceptions of cable changing the sound of a given system. Let's leave this for another debate aka food fight . We are discussing the perception change to the sound after a cable has been cooked (thorugh a very particular device doing a number of unexplainable things) or burned-in by just playing music ofr some special signal thourgh it. So far the explanations for such have been tenuous at best and over-reaching would not be ou of place to qualify these.
This question will surely raise the anger of the burn-in believers, I am again asking if anyone feels confident enough to test their ability to identify reliably a burned-in cable from an un-burned, uncooked one?

I am honestly having a very hard time trying to understand your point of view.

So far this thread has included: 1) references to the literature of two different manufacturers (Cardas and Audioquest) formulating hypotheses of what happens with cable burn-in; 2) posts by three additional cable manufacturers stating their opinion that cable burn-in is a real phenomenon; 3) an interesting (albeit serendipitous) double-blind test supporting the audibility of cable burn-in. Yet, you summarily dismiss all of this stating "Many have gotten very defensive about their perceptions being questioned and skeptical views have been dismissed or sneered at" and "So far the explanations for such have been tenuous at best and over-reaching would not be ou of place to qualify these".

Care to start by at least being specific as to what you find "tenuous" and "over-reaching" in the Cardas and Audioquest literature about burn-in?

 

[dmnc02]

I think I can help, manufacturers and dealers are trying to sell you stuff!
Is that better?
Keith.

How does burn-in help manufacturers sell their cables?

 

[dmnc02]

Really? You have never been told this, your cable doesn't sound any ,different/better that's because it has burned in yet.
Not happy with the sound of your new amplifier, just wait until it has burned in!
Actually of course the only time when you might genuinely hear any differences in components is within the first 20 minutes until your ears have become accustomed to the new sound.
Keith.

If you believe (as you seem to do) that your ears get accustomed to your gear over time, you should agree that the only way to evaluate new gear is to give your ears time to re-adjust to it. But coherence does not seem to be your strong suit.

 

[Robh3606]

Hello Dnmc02

How does burn-in help manufacturers sell their cables

It doesn't however to be a wise guy from a skeptical point of view are the cables changing or is it your perception that is changing. That's why I would like to see some kind of before and after measurement's.

I am a bit confused why any changes in the dielectric from burn in would have an effect in interconnect cables. It's a real potential issue with capacitors where the signal must pass through the dielectric material simply because of the basic construction of a capacitor. With interconnects the dielectric is used as a barrier to insulate the conductor runs. The signal does not pass through the dielectric like it does in a capacitor. Why would changes in the dielectric effect the sound in interconnects??

Rob