| zBuff |
As far as I can see the only way people know how to do this so far is to insert the a said component into a audio path and listen for it. I was thinking perhaps there might be another way. Directionality is said to be a due to the construction and fabrication process, the way the metal is stretch and extruded. Now using a microscope it should be possible to determine this if one know what they are looking for. I'm going to try it out myself once I get access to a sufficiently powerful microscope. Anyone with experience/knowledge in metallurgy and/or component manufacture that could give some insight into how you could determine directionality visually.
Please no comments whether or not such audible directionality exists or not, such comments help no one. If u wish to comment as such, please do it on another thread as there are plenty of them around, rather than to create another cesspit of contentious bickering. :rolleyes: |
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| phn |
Not much help, perhaps, but I make the habit of hooking up cables in the direction of the printed text. Doesn't help much if you make a cable from scratch, though.
I don't know how it works outside of Europe, but the AC jacks here are actually "directional." In other words, it makes a difference how you connect the power cords. I think it makes a lot more difference than hooking up wire in the "right" direction. That doesn't mean I scoff at the latter. It's free, so why not try? |
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| SY |
I've had quite a bit of professional experience in the production of wire and electronic components. You don't want to hear this, but it really is a crock.
With tubular caps, there is at least some logical reason why there MIGHT be a difference in some very limited circumstances (outer versus inner foil). But if you ever watched, e.g., resistors being assembled, you'll understand immediately why directionality can't possibly matter. Don't bother measuring, you've got the laws of physics working against you. |
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| Bill Fitzpatrick |
| quote: | Originally posted by zBuff
Please no comments whether or not such audible directionality exists or not, such comments help no one. If u wish to comment as such, please do it on another thread as there are plenty of them around, rather than to create another cesspit of contentious bickering. :rolleyes: |
Yet . . .
What a load of ****. See $485 wood knob on other thread. Anyone spending more than 2 minutes thinking about wire directionality shoud have their head examined. If one used bi-directional wire they wouldn't have to worry about such things. Think about it - first the electrons go this way and then they go that way - back and forth, back and forth, back and forth . . . |
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| 454Casull |
| quote: | Originally posted by zBuff
Please no comments whether or not such audible directionality exists or not, such comments help no one. |
Ah, but if we were to convince you that the effect did not exist, you would not waste your time on such an endeavor. |
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| john curl |
| Just try the cable in both directions. It is easier to listen for a difference, than to see it or measure it. I believe that it can be important, sometimes. |
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| chipco3434 |
...snip
Please no comments whether or not such audible directionality exists or not, such comments help no one. If u wish to comment as such, please do it on another thread as there are plenty of them around, rather than to create another cesspit of contentious bickering.
...snip
Your best site for "research" on "directionality" is www.audioasylum.com's cable section. Please check it out. It's full of "science" but please be aware that any mention of ABX or double blind testing will get you a harsh reprimand. I suspect that the scientific method might be a little off topic there also.
You will find it a continuous source of amusement. Please be sure to change you outlet covers! Evidently dramatic improvements are seen with stainless covers when compared to plastic.... |
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| phn |
While I do hook up cables with the text going in the direction of the current, that's purely a matter of aesthetics and convenience. Even without markings, I know which RCA is connected to the shield.
Though I from own experience can say with absolute certainty that "burning in" cables is an old wife's tale, I have no experience whatsoever from wire direction. At least Van Den Hul flatly rejects the idea, though.
Anyway, the idea that it should matter how you connect the AC cord interests me. What interests me about it is that the idea that direction could matter with alternating current is completely foreign to me. But at the same time, the web page that mentions it actually makes sense. It's here. Unfortunately in Swedish, and my halting technical lingo prevents me from translating it. It has to do with how gear hooked up to the same power line can interfere with each other.
So my question is, have I lived under a rock or has somebody else heard about this before? |
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| pinkmouse |
| It has been discussed on the board before. However, it is very dangerous if done without appropriate attention to detail. If you just swap the leads going into the device you imediately remove any internal fuse protection, as well as possibly bypassing the mains switch, (if it is single pole), thus meaning that the internals could be live even if switched off. The only was to do this safely would be to swap the primaries on the traffo, and leave any other internal or external leads well alone. |
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| phn |
| Thanks, pinkmouse. Now I can go back to my normal life. |
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| GRollins |
I rarely participate in threads like this anymore. Why? Because it's the sort of thing where people treat science like a religion and that irks me. In doing so, they demonstrate a bothersome lack of comprehension as to the proper workings of science, amongst which is the dictum,"Question everything. Especially the things you think are bedrock knowledge." Jeez, Newtonian physics worked, right? Who'd want to believe all that hocus pocus quantum nonsense. Relativity? Bull feathers! I have an entire book at home wherein the author goes on at length about how Einstein can't be right because of this and this and this and...we know who won that argument, and it wasn't the common sense science we had learned at our teachers' knees.
Cable directionality exists.
Get over it.
Now, I will be the first to admit that it shouldn't. My initial reaction when first told that cables had one direction that sounded better than the other wasn't printable. Not on this web site. I didn't believe it. Didn't want to believe it. And said so loudly and at length, with all sorts of scientific proof. There was just one tiny, little, bitty problem:
I was wrong.
Of course, people have been demonstrating that we can hear things that weren't measurable (yet) for years. Passive components have a sonic signature? Check. Easily verifiable once you know what to look for. Absolute phase? Check. I have to hand it to Douglas Self, the man had the courage to admit in his if-it-ain't-measurable-it-don't-exist book on amplifier design that the audibility of absolute phase had been proven--this after ranting against it in a previous edition. That must have cost his ego dearly, but he was man enough to swallow his pride and get on with it. The list goes on. For crying out loud, some people even denied that such a thing as an image existed. Though it isn't measurable, per se, I think that the majority of members here--excepting, perhaps, Bose owners--accept the existance of a stereo image.
I do not have an explanation, even of the vague hand-waving sort, for what causes a cable to have a direction. I've heard ideas put forth that it has to do with the direction that the wire was drawn through the die during manufacture and whatnot. I have somewhere an e-mail forwarded to me that came from the head of NAD saying that he didn't know what caused it, but could say from experience that wire acquired directionality when the insulation was put on. I do not claim to know which, if any, hypothesis is correct.
I am not aware of any way to determine directionality except to listen. What we need is some clever lad or lass to do for this what Jung and Marsh did for capacitors back in the '70s. Once they elucidated how DA and other reasonable factors made a difference, it became clear as day, and measureable. The thing to realize is that people withstood precisely the same mockery prior to their work that cable folks endure today. Capacitors change the sound? Get outta here! One microfarad is as good as another. And on and on it went. You just have to be old enough to remember the ridicule.
Now, for some reason, ignorant people immediately assume that if you buy something as outlandish as cable directionality you obviously also buy into every other crackpot idea out there. Nope. Ain't so. I do not, for instance, intend to buy a volume knob made out of beech that costs enough to feed my family for many nights. On the other hand, I do not intend to make fun of them. I have better things to do with my time. Besides, fate has a funny way of biting back, and it's easier to change your mind if you don't have to defend your pride at the same time.
My rule of thumb is this: If you can hear absolute phase on your system, then try listening to cables one way, then the other. If you cannot hear absolute phase, then don't bother trying. They are on roughly the same level of subtlety. The effect is most obvious in the high frequencies and image. As a practical matter, I regard it as one of the last things to do in tweaking a system. I have never gone to the trouble with the internal wiring in a piece of equipment. I can see that it might be worthwhile, it's just that I've not made the effort, given that it's a low level effect and the total length of wire in most pieces of equipment is fairly short.
Grey
P.S.: I suppose that it's one of those human nature things that once something is proven, it's those who were most dead-set against it that you hear saying,"I knew it all along!"
That doesn't keep me from wanting to punch them in the nose.
I'm human, too. |
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| pinkmouse |
As a fortean, I endeavour to keep as open a mind as possible, but there is an old maxim, that extraordinary claims require extraordinary evidence. I have yet to see or hear this evidence regarding cable directionality. I'm not saying it doesn't exist, but I personally have no proof that it does, and there is a lot of evidence to say it doesn't.
But hey, persuade me! :) |
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| phn |
I know bringing up "subjectivists" and "positivists" (not the political ideology) is the easiest way to get knocked here. But it's always the former that resort to logical fallacies.
| quote: | | Who'd want to believe all that hocus pocus quantum nonsense. |
No positivist has ever objected to quant physics. It's a science for crying out loud! If it wasn't you would read about it in Stereophile or the equal-minded National Enquirer.
And to equate science to religion is plain silly. Not to mention that it's another logical fallacy.
It's useless to try refuting you post since it makes no sense. |
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| GRollins |
C'mon, man, you can do better than that. There's no such thing as 'evidence to say that it doesn't.' You can't prove a negative. Yes, it makes things like this difficult to discuss, especially in the absence of a proposed mechanism as to what might be happening. Let me restate that--I am not proposing a mechanism, though others have and some even sound a little bit plausible, though I have yet to hear a hypothesis that just grabs me by the collar and won't let go. Trust me, I'd sleep better at night if I had a handle on this one. It is counterintuitive, to say the least. I first ran into it back when I was selling stereo gear. They practically had to drag me kicking and screaming into the listening room. All I could do for days afterwards was grumble and give people nasty looks. It took time for me to get over it.
Along those same lines, I saw a report a few days ago that sunlight might help cure or at least retard melanoma (i.e. skin cancer). Say what? UV from the sun has long been regarded as the primary causitive agent for melanoma. How can it possibly help? The researchers admit that they are stumped, but have a provisional hypothesis that it's the vitamin D generated in the skin by the sunlight that is the beneficial agent. They hope to pursue that angle if they can get funding.
Life gets weird sometimes.
I try to surf the changes as gracefully as possible.
Grey |
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| Bill Fitzpatrick |
| quote: | [i]
Along those same lines, I saw a report a few days ago that sunlight might help cure or at least retard melanoma (i.e. skin cancer). Say what? UV from the sun has long been regarded as the primary causitive agent for melanoma. How can it possibly help? The researchers admit that they are stumped, but have a provisional hypothesis that it's the vitamin D generated in the skin by the sunlight that is the beneficial agent. [/B] |
I think it's excess vitamin D that causes skin cancer. |
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| phn |
I understand you burn for what you do. I would never want to deny you or anyone else his or her hobby. In fact, I think it's great what you do. I'm behind your every step.
I can come of cold sometimes. But don't believe for a second I am. I'm old enough not to mind being called a sap, which I often am. I'm still bugged by a post I wrote some time ago. I stand by what I meant, just not how I put it. I wrote something about what shame it was people here didn't put in the effort making more attractive enclosures for their gear. I meant more personal, as in creative. Thinking about it, I'll write a late reply tomorrow. Now it's bedtime. |
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| pinkmouse |
Grey, you're quite correct, you can't prove a negative. My only excuse for such vague language is that it's 2:30 in the morning here, and I have insomnia, and some sort of bug that is giving me a thick head. The only thing I am fit to do is provoke debate here, but I know you get my point.
As for the melanoma studies, I remember reading about that a year or so in New Scientist. If I remember, it comes down to the balance between visible and U/V light. It actually makes sense though, in sunny areas you need the maximum protection against U/V, so the natural defense mechanism should be triggered by the problem. |
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| GRollins |
phn,
You betray a lack of historical perspective. Go back and look at the response to discoveries in their own time frame, not ours. Of course it's regarded as hard fact now, the point is that it wasn't then.
Surely you realize that relativity wasn't well received. Einstein himself didn't like some of the implications. His "spooky action at a distance" comment is quite famous.
How to treat science as a religion? Easy. Treat everything known at a given point in time as holy writ, not subject to questioning. The history of science is rife with established theories being overturned by new evidence...against the wishes of the old guard. Those who want science to remain unchanging are treating it as a religion. One of the functions of religion is to be unchanging. If religions allow questions, then they have to admit that they are not infallible. If they are not infallible, then clearly they are not based on (insert deity of your choice here)'s word. At which point, their entire structure comes apart at the seams.
If you doubt that some people wanted to freeze science in much the same way, then all I can say is that you need to spend some time reading about the reactions to various scientific discoveries, not just among the public (e.g. Darwinism), but among scientists.
Grey |
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| GRollins |
pinkmouse,
Go to bed. I'm not upset. All is well.
Grey |
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| pinkmouse |
Yes Boss.
Goodnight all... |
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| Sch3mat1c |
Ah, another pseudoscientist.
That makes two or three.
I hate pseudoscientists.
Tim |
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| TerryO |
Gray,
You wrote:
If you doubt that some people wanted to freeze science in much the same way, then all I can say is that you need to spend some time reading about the reactions to various scientific discoveries, not just among the public (e.g. Darwinism), but among scientists.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Grey,
I couldn't agree with you more. Darwinism is an excellent example as more and more scientists in the last 25 years have found insurmountable problems with Darwinian (or Neo-Darwinian) theory. Hardliner Darwinists are in the position of frantically trying to plug the ever increasing holes in the dyke. However, the science teachers (and many text books) in the school system still reiterate the same examples that have been discredited in the last 30+ years (the same ones that I studied in school).
As regards wire and cables, these old ears can't hear the difference. But then again, I know that high frequencies exist even if I can no longer hear them directly.
Best Regards,
TerryO |
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| Mr Evil |
| Regarding science accepting new theories: New theories are supposed to be rejected at first. The originator must then go about collecting the huge amount of rigorous proof required for acceptance to be begun. Most new theories never get that far because they are false, which is the whole point. |
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| TerryO |
Mr. Evil wrote:
Regarding science accepting new theories: New theories are supposed to be rejected at first. The originator must then go about collecting the huge amount of rigorous proof required for acceptance to be begun. Most new theories never get that far because they are false, which is the whole point.
~~~~~~~~~~~~~~~~~~~~~~~
That's what's odd about Darwin's theory, there really wasn't much proof at the time, which Darwin was aware of, but it was thought that future discoveries would supply the necessary evidence or at least a comfortable level of confirmation. Time has not been kind to Darwin's theory.
I was unaware that theories are supposed to rejected initially. In my experience constructing experimental design, you always proposed a negative hypothesis. Obviously, any new theory must undergo rigorous peer review before it is accepted (at least that's the theory:^)
Best Regards,
TerryO |
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| SY |
Relativity and quantum mechanics were attempts to explain well-established physical facts that were well known not to comport with classical physics. I don't see the analogy.
Perhaps the story of Blondlot and Wood could be instructive. |
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| Keithj |
| quote: | Originally posted by TerryO
Mr. Evil wrote:
Regarding science accepting new theories: New theories are supposed to be rejected at first. The originator must then go about collecting the huge amount of rigorous proof required for acceptance to be begun. Most new theories never get that far because they are false, which is the whole point.
~~~~~~~~~~~~~~~~~~~~~~~
That's what's odd about Darwin's theory, there really wasn't much proof at the time, which Darwin was aware of, but it was thought that future discoveries would supply the necessary evidence or at least a comfortable level of confirmation. Time has not been kind to Darwin's theory.
I was unaware that theories are supposed to rejected initially. In my experience constructing experimental design, you always proposed a negative hypothesis. Obviously, any new theory must undergo rigorous peer review before it is accepted (at least that's the theory:^)
Best Regards,
TerryO |
I thought that part of the scientific process was that someone proposed an hypothesis; an hypothesis being a stab at how something works. That hypothesis is tested and, once sufficient evidence for it is found, becomes a theory. Supposed to be rejected? Uh no, supposed to be tested, yep.
As for Darwin, I propose you read two books, The Blind Watchmaker and Climbing Mount Improbable, both by Richard Dawkins.
Now the difference between science and religion to me, is simple. One requires faith/belief (religion) and thus iis likely to be unquestioned. The other requires testing, testing and more testing, that is, evidence.
cheers, Keith |
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| DigitalJunkie |
Just to add my 0.02...
I've got a MonsterCable subwoofer cable,and it has an arrow on one end,showing the direction of the signal.
At first I though "How can wire be directional,it's just wire!?"
Then I decided to unscrew the covers on the RCA plugs..
A-Ha!
There were 3 conductors in the cable,signal,ground,and another ground wire which was connected at only one end.
I've since read a bit about this,and I believe it is called "Semi balanced".
It may make sense that a cable is directional because it is using a "semi-balanced",or some other,similar setup.
Beyond that,I'm skeptical that plain old wire can be "directional".. |
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| audio-kraut |
| quote: | | There were 3 conductors in the cable,signal,ground,and another ground wire which was connected at only one end. |
and thats how you fool people into believing things.
Just like some magicians trick - you have to take it apart to find the truth.
| quote: | | Darwinism is an excellent example as more and more scientists in the last 25 years have found insurmountable problems with Darwinian (or Neo-Darwinian) theory. |
Yes especially those spouting the so called "intelligent design" bull.
Darwins theory - with fine tuning - works just nicely, thank you, and gets validated almost each day by the findings of dna analysis. |
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| janneman |
| quote: | Originally posted by GRollins
I rarely participate in threads like this anymore. [snip]Cable directionality exists.
Get over it.
[snip] |
Grey,
I liked your post, and think you are one of the few people here to see the value of scientific method for almost any human endeavour - at least if your really serious about what you are doing.
At the same time though, your post is somewhat trying to ride two bikes at the same time. On the one hand you advocate rigourous testing of theories, being sceptic, etc. On the other hand, you want us to take your word that cable directionality exists.
(I assume we are NOT talking about directionality as pointed out earlier that results from single-end grounding only. I assume we talk about directionality in a cable that is otherwise end-for-end identical).
I don't know if cable directionality exists; I have never experienced it. But IF it exists, why not produce an irrefutable proof in the great scientific tradition that you seem to advocate so strongly (and which I wholeheartedly support)?
Jan Didden |
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| AudioFreak |
| quote: | Originally posted by Keithj
The other requires testing, testing and more testing, that is, evidence. |
Couldn't agree more and that's also why the bulk of archeological science and similar studies are not science. They can guess all they like but they can not go back in time to when it all began to test their theories. |
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| janneman |
| quote: | Originally posted by AudioFreak
Couldn't agree more and that's also why the bulk of archeological science and similar studies are not science. They can guess all they like but they can not go back in time to when it all began to test their theories. |
Dan,
I don't quite agree. We cannot go to the sun to test in situ the composition, but we can deduct and proof what it is. You can proof who committed a murder even if you were not present. What we call proof is "beyond a shadow of a doubt", in the legal sense as well as in the scientific sense.
Jan Didden |
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| pinkmouse |
Terry
I suggest you actually do some reading on evolutionary theory, but go back to what the scientists actually say. Yes, some of the examples given in old text books have proven to be incorrect for the traditional reasons, and this has been jumped on by the ID brigade, but if you actually look at the science behind the refutation, it actually shows a much more elegant demonstration of evolution than the original case.
Please go out and actually read up on this, the Peppered Moth case in particular is a fascinating story of real people, and make your mind up for yourself, don't just believe a load of nonsense perpetrated by those with an agenda, (of any side). |
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| Mr Evil |
| quote: | Originally posted by Keithj
I thought that part of the scientific process was that someone proposed an hypothesis; an hypothesis being a stab at how something works. That hypothesis is tested and, once sufficient evidence for it is found, becomes a theory. Supposed to be rejected? Uh no, supposed to be tested, yep... |
I wasn't talking about the scientific method per se. It is the job of the person(s) proposing a theory to apply that. The scientific community on the other hand should never accept a new theory at first, otherwise we would be overrun with a multitude of crackpot theories that changed every day. |
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| audio-kraut |
In the whole discussion about the "sound" of cables: why is ist that from all the discussions I have read/participated in so far, there seems to be no problem with the sound of an xlr terminated balanced cable?
All the discussions seem to centre on unbalanced rca terminated cable.
Could that not be a hint that its not the cable per se but the nature of the unbalanced connection that determines "cable sound" - i.e. induced noise?
So all phenomena attributed to the construction and the resulting sound of this or that rca cable may be can be reduced to that? |
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| janneman |
| quote: | Originally posted by audio-kraut
In the whole discussion about the "sound" of cables: why is ist that from all the discussions I have read/participated in so far, there seems to be no problem with the sound of an xlr terminated balanced cable?
All the discussions seem to centre on unbalanced rca terminated cable.
Could that not be a hint that its not the cable per se but the nature of the unbalanced connection that determines "cable sound" - i.e. induced noise?
So all phenomena attributed to the construction and the resulting sound of this or that rca cable may be can be reduced to that? |
I would think the balanced thing does make a difference, but I think the simple reason is only a tiny proportion of the hi-fi crowd uses XRL, they are overshouted by the majority that uses RCA.
Jan Didden |
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| phn |
| quote: | | I would think the balanced thing does make a difference, but I think the simple reason is only a tiny proportion of the hi-fi crowd uses XRL, they are overshouted by the majority that uses RCA. |
Now this thread is heading somewhere interesting. As a vinyl junkie I have never understood the idea behind unbalancing an inherently balanced MC cartridge. And if there was something the balanced circuitry was invented for, it was low-output MC cartridges. For digital gear you can use just about any conductive material you can find for interconnect cable and it makes no sonic difference. I guess that's the reason unbalanced gear and antiquated RCAs are still around, to keep the cable makers in business. |
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| janneman |
| quote: | Originally posted by phn
Now this thread is heading somewhere interesting. As a vinyl junkie I have never understood the idea behind unbalancing an inherently balanced MC cartridge. [snip]I guess that's the reason unbalanced gear and antiquated RCAs are still around, to keep the cable makers in business. |
Maybe, but there is also the inherent additional cost to make equipment balanced vs unbalanced. With the current low prices of opamps and stuff, this may no longer be significant, but in the times where each transistor counted, the market would just not support all-balanced home equipment. Only professional cost-no-object gear could afford it. So there are probably alot of just historical reasons (hey boss, we ALWAYS did it this way, and it sold, didn't it?).
| quote: | Originally posted by phn
[snip] For digital gear you can use just about any conductive material you can find for interconnect cable and it makes no sonic difference. [snip] |
... duck!...
Jan Didden |
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| phn |
I would love to hear somebody try to explain why his (it's always a he, isn't it?) ones and zeros sound different from mine. |
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| janneman |
| quote: | Originally posted by phn
I would love to hear somebody try to explain why his (it's always a he, isn't it?) ones and zeros sound different from mine. |
Well, what I understand is that with some cables the rising and falling edges of the digital signal are becoming like triangle waves, and then the switching point can vary, so the edges are no longer in their original position. Something like jitter?
I am no expert here, so I don't know if the effect is real, or by what mechanism that would become audible. But I think that's the story.
Jan Didden |
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| phn |
| You're right. Better go the full nine yards and get that 75 hz coaxial cable. Like this one. At $14 you can't really feel cheated even if it proves to be no better than a cheaper alternative. I mean, it looks like a million bucks. And looks are important. Really.:cool: |
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| vpharris |
phn:| quote: | | I have never understood the idea behind unbalancing an inherently balanced MC cartridge. And if there was something the balanced circuitry was invented for, it was low-output MC cartridges. |
Just the other day, I saw that N. Pass gave a reason why phono inputs aren't typically balanced in another thread. He said...
" No reason you couldn't do it, but I will point out that using
active balanced inputs on phono stages is very difficult. Usually
the common mode noise is so large that you find that it runs
quieter with one input grounded. This effect comes from the
fact that significant noise reduction is ordinarily achieved by
having one side of the cartridge's output grounded, which really
loads down any stray noise pickup. When we want to float the
output of a phono cartridge, the usual solution is to use a
transformer." |
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| phn |
Feel free to go OT.
Now, I'm not an electrician. But doesn't "When we want to float the output of a phono cartridge, the usual solution is to use a transformer" describe just a balanced circuit?
And being that I'm not an electrician, I can't judge the pros and cons of a transistor balancing. But I snatched this long quote from http://www.dself.dsl.pipex.com.
<<Electronic balancing has many advantages, such as low cost, low size and weight, superior frequency and transient response, and no problems with low-frequency linearity. While it is sometimes regarded as a second-best, it is more than adequate for most professional applications . Transformer balancing has some advantages of its own, particularly for work in very hostile RF/EMC environments, but many serious drawbacks. The advantages are that transformers are electrically bullet-proof, retain their CMRR performance forever, and consume no power even at high signal levels. Unfortunately they also generate LF distortion, have HF response problems due to leakage reactance and distributed capacitance, and are heavy and expensive. The first two objections can be surmounted given enough extra electronic circuitry, but the last two cannot. Transformer balancing is therefore rare, even in professional audio.>> |
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| analog_sa |
| quote: | | I would love to hear somebody try to explain why his (it's always a he, isn't it?) ones and zeros sound different from mine. |
Phn
You may, or may not realise that mentioning ones and zeroes for a system which uses an embedded clock is a pretty clueless statement.
Yup, 'digital' (they are not really digital, are they?) interconnects do make an audible difference. They provide a varying degree of unpleasantness. |
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| phn |
| Yes, they are "just" ones and zeros. It's all we've got. The analogue out from the amp is a completely different matter. |
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| analog_sa |
| quote: | | Yes, they are "just" ones and zeros. |
Sorry, but without a clock these ones and zeroes are pretty meaningless.
Interestingly i hear very little difference between analogue cables out of the DAC. I guess the dismal resolution explains it. |
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| phn |
| I'm not talking about the hardware. I'm talking about cables. And once the signal has left the DAC it's just ones and zeros. Hence, virtually impervious to outside interference. Even a "roughed up" one or zero the digital amp will interpret as either a one or a zero. It doesn't understand anything else. |
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| mikelm |
| quote: | Originally posted by phn
I'm not talking about the hardware. I'm talking about cables. And once the signal has left the DAC it's just ones and zeros. Hence, virtually impervious to outside interference. Even a "roughed up" one or zero the digital amp will interpret as either a one or a zero. It doesn't understand anything else. |
Steady on phn, there may be guys reading this that have designed and built many dac's and all of them know that low jitter is critical. In fact in many early CD players it was a major contributor to the dreadful sound we had to endure for years.
ps the o/p of a DAC is analogue, digital comes out of a ADC
mike |
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| phn |
Maybe my fault. I'm talking digital out, like spdif. And the digital signal is ones and zeros only. A "half" one will not sound any different than a perfect one. The digital amp will read both as one. So the cable doesn't matter, within reason. Like the $14 cable I linked to.
So lets make two points clear, since I obviously used wrong tech lingo.
First one is Transport and DAC do matter.
The second is that I don't care what cables somebody buys. Never have. (If I did I wouldn't mention it since it's irrelevant. That would be MY problem.) As I posted yesterday, I will not deny anyone his or her hobby or pleasure. If somebody wants to buy a Reference 75 Ohm Digital Link, fine. But don't pretend it's anything different than buying designer clothes.
What bugs me is the false marketing by Transparent Cable. "The large, polished OFHC center conductor is surrounded by proprietary air/spiral teflon insulation to reduce noise" is probably true. But they don't tell you that reduced noise doesn't make any difference in a digital cable, since a digital amp can't read noise the way an analogue amp do. |
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| r0cket- |
| quote: | | Originally posted by phn But they don't tell you that reduced noise doesn't make any difference in a digital cable, since a digital amp can't read noise the way an analogue amp do. [/B] |
I'm generally with you on this, however, I'd say that if nothing else, it can't hurt to keep noise out of a digital circuit, even if it isn't likely to be deterimental to the circuit's performance. |
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| mikelm |
Your digital amp, if you feed digital into it, is a DAC - a power DAC.
PLEASE go out and find out about digital design before you make such bold statements.
Unless you have an extremely expensive set up that really cleans up the digital signal before it goes to the DAC, the jitter that it may have picked up, anywhere in the digital chain, will create havoc with the sound quality when it is converted to analogue.
This is something that is clearly & mathamatically understood by hundreds of digital engineers that have been earning their living from digital audio design for many years.
Cables and their plugs and sockets can contribute to jitter so it is very easy to understand how they make a difference to audio quality.
good luck....;)
mike |
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| phn |
| I'm not talking about jitter. I'm talking about the signal. If the signal is right in the first place then the cable doesn't matter, again within reason. The ones and zeros are impervious to noise. A "one" can only be a "one" and a "zero" only a "zero." Noise is neither. Over long distances, talking miles, the signal can degrade to a state where the receiver can't read them. That's obviously not a problem in an interconnect. |
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| SY |
| I'm pretty ignorant about this stuff- does a normal level of jitter at the receiver correlate 1:1 with jitter in the conversion? If so, it should be easy to measure in the analog output signal as plain vanilla THD+N. |
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| phn |
| quote: | | I'm generally with you on this, however, I'd say that if nothing else, it can't hurt to keep noise out of a digital circuit, even if it isn't likely to be deterimental to the circuit's performance. |
I agree. I have bought lots of stuff because it's better to be safe than sorry. Like Teflon-isolated wire. Since Teflon, as far as DIY goes, only costs marginally more than PVC, and OFC really costs nothing at all, there's no reason not getting it.
It's just funny that when you question cables, the cable fans immediately make it an either or proposition. That's like saying either you're abstinent or an alcoholic. Like if there isn't a whole spectrum in between.
I believe in sound material and construction. But I'm not going to pay $10,000 for the capacitor and hoodoo you find in the Transparent box. I can make an identical cable (if I wanted one) sans the hoodoo for a fraction of the cost. Of course, it won't look like a million bucks or say "Transparent." |
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| GRollins |
As these threads often do, this one has accumulated a number of posts in the last twenty hours or so. I'll try to hit the high spots.
Regarding TerryO's post: I find it interesting when people read things into my writing that I did not intend. In a way, I guess it's helpful in the sense that it goads me to write ever more clearly.
Evolution is a remarkably succinct and wide-ranging theory that works extremely well. Is it perfect? I doubt it. But then to say that there are "problems" with Darwinism also leads one to contemplate the "problems" in physics, astronomy, geology, etc. Are we to demote all of these fields to the level of superstition? No. To latch onto things such as questions regarding the rate at which species evolve as so-called 'evidence' that the theory is fatally flawed shows a remarkable blindness as to how science operates.
Speaking broadly, the people who want Darwinism to go away are almost always religious zealots with a rather obvious axe to grind. It chips away at a fundamentalist's authority every time science explains something in a non-supernatural way. Historically, this has happened many times. Science always wins. We all acknowledge at this time that the Earth is not the center of the universe. It's not even the center of our Solar system, much less the Milky Way or universe. Yet the Church (note capital C) fought this desperately. Read your history books. It is happening again in our time with evolution. Anger, willful misrepresentation, fear...all these things have happened before, and no doubt will again.
To pinkmouse's post about moths, I would add Darwin's Finch of the Galapagos Islands. Very illuminating. Very clear. "Think of it as evolution in action," as the man said.
Um, let's see here...I scribbled a few quick notes as I came though. I wanted to say to digitaljunkie that all my experience with cable directionality has been with unbalanced cables. I have no opinion regarding balanced ones. (The only reasonable position until I get a balanced system going, get familiar with it, and then try cables.) At some point in the future, I may post on this, but can't say anything useful at this time.
Janneman,
Your post is good. Here is my position, which I think I've stated before, but it's been a while.
Your request for evidence is quite reasonable. Our problem is that, lacking a hard science (i.e. meters) way to register cable directionality, we have to fall back on soft science. This requires guinea pigs to sit in a room and correctly identify cable direction to some statistically significant degree, and even that is open to criticism in some quarters in the sense that there are always people who want the test set up some other way from the way it was done.
I, myself, have served as such a guinea pig. I'm tired of being treated like a circus freak. (Look, Mama, there's a man with two heads...and over there a man with Golden Ears...) I'm here to tell you it gets damned old. Once or twice is okay. But there's always someone coming in saying that the previous test was flawed because of this or that, and you've got to do it all again or you'll hear the same old tired refrain:
"Ha! I knew it was ****! You're afraid to listen under my carefully controlled scientific conditions," quoth he.
"It's not that, it's that I've participated in three 'carefully controlled scientific' tests in the last two months and I promised I'd take my wife out to dinner tonight."
"That's an excuse!. Admit it...you can't really hear these things you say you can hear...."
And on and on and on and on...
And so it finally gets proved to person X's (grudging) satisfaction. Two years pass, and the cycle starts up again. By which point X has moved away and is no longer willing to testify on your behalf anyway, as he has quit audio and taken up fly fishing. Couldn't care less. He's bought himself a table radio and listens to Rush Limbaugh all day.
Jan, it gets old. I'm not trying to turn you away on this, man, but I'm tired of it. All I can suggest is what I've said before: Try to develop a hypothesis that might explain the observational data and test it (but be prepared to formulate more hypotheses if the first one doesn't work, as the phenomena is real--yes, this will take patience and dedication). The other possibility is to listen for yourself if your system is good enough. As I think I said earlier in this thread, it's mainly in the high frequencies and imaging. (As opposed to, say, absolute phase, which is most obvious in the impact of drums.) To me this suggests that it's a detail retrieval thing, but how the hell to test for detail I don't know. If I knew that, we might be able to resolve some of the tube vs. solid state questions or class A vs. AB, that sort of thing.
One thing I must caution against--don't try this on any system that you are not very, very familar with. You don't take a guy into a room, have him look around, take him out in the hall while changes are made, then bring him in again and fuss because he didn't pick up on the fact that the vase on the end table was moved six inches. It's all different to him and he's overwhelmed trying to memorize a thousand details that are new to him.
For what it's worth, this is the only oddball thing that I vouch for. Everything else, as far as I know, has either been proven or else my position has been stated as,"No opinion."
Grey |
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| scott wurcer |
| quote: | Originally posted by phn
Now this thread is heading somewhere interesting. As a vinyl junkie I have never understood the idea behind unbalancing an inherently balanced MC cartridge. And if there was something the balanced circuitry was invented for, it was low-output MC cartridges. For digital gear you can use just about any conductive material you can find for interconnect cable and it makes no sonic difference. I guess that's the reason unbalanced gear and antiquated RCAs are still around, to keep the cable makers in business. |
I've run balanced phono for 25yrs and never had a noise problem. Careful design of the front end can give common mode rejection nearly as good as a transfomer, cetainly to the point of diminishing return. |
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| GRollins |
Scott,
Any tips? I'm smack in the middle of a balanced phono design and anything you've got to say on the subject would be of great interest.
Grey |
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| phn |
Grey, I can't ignore the effort you have put in. But it also makes it next to impossible to reply. I also believe we had this discussion yesterday.
But I can say this. I think this forum shouldn't be too much concerned with personal opinions. As a DIY forum it should be concerned with how things actually are. Sometimes the scientific findings and subjective opinions converge. Be as it may, but in the end, sticking with facts is what results in improvements and innovations. The Transparent hoodoo box doesn't help anyone here make better gear. |
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| Bratislav |
| quote: | Originally posted by GRollins
I rarely participate in threads like this anymore. Why? Because it's the sort of thing where people treat science like a religion and that irks me. In doing so, they demonstrate a bothersome lack of comprehension as to the proper workings of science, amongst which is the dictum,"Question everything. Especially the things you think are bedrock knowledge."
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Can I ask a simple question here ? Like, does audio cable carry something OTHER than plain vanilla electrica signal ? In other words, audio or something else, does it really matter ? And if does, why ?
| quote: |
Cable directionality exists.
Get over it.
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Then let's go further. *If* the answer to my question above is "no, there's no audio related subatomic particles carried through the cable, just good ol' electrons modulated by electrical field", THEN we can conclude that *other* applications should benefit from this newly found knowledge that cables are *ahem* directional.
Applications that require sensitivity and freedom from distortion FAR beyond simple audio. Like say, capturing single neutrino pass through a container of millons of galons of ultra pure heavy water, where detectors are so sensitive that ANY stray light, no matter how small, would instantly pop all the photomultiplier valves like old flash bulbs (it actually happened once).
Or, capturing ancient light so tired from getting across the universe that it's redshifted into radio long waves, and trickles at rate of one photon per hour. Or, capturing the primordial ripples in echoes of a Big Bang, mapping the cosmic backround radiation to the unprecedented precision, trying to "see" the seeds of matter as we know it, forming.
You would think those application need to know about cable directivity, no ? After all, if one direction works better (that is has less distortion), this would prove to be a major advantage. I can see a few postdoc dissertations in this, and why not, even a Nobel prize.
What, no takers so far ? Strange. Very strange. Almost as strange as the fact that all the cables I saw hanging off state of the art devices like 2dF and 6dF spectrographs at AAO do NOT seem directional in any way, they look just random cut offs of, admiteddly high tech, coax cable. Same at Parks radio telescope. Same at all scientific institutions I've been to, where lots of people would give body parts to get another decimal point of freedom from noise and distortion.
Are they just plain ignorant ? Are all people making scientific intrumentation just blinded by the dogma ? I find that hard to swallow, knowing at what lengths people will go to stamp their name over something genuinely new and groundbreaking as, *ahem* cable directivity.
| quote: |
I didn't believe it. Didn't want to believe it. And said so loudly and at length, with all sorts of scientific proof. There was just one tiny, little, bitty problem:
I was wrong. "
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Well, I'd like to be able to step up to that level of knowledge. Can you give some pointers on how do we PROVE this, using same "scientific proof" ? Because, without the proof, we have yet another theory. Nothing more.
Bratislav |
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| SY |
| This does not rise to the level of a theory yet. At this point, it's unsubstantiated assertion. With some actual EVIDENCE, a theory can be constructed. |
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| GRollins |
I agree that it does not rise to the level of a theory, nor even that of a hypothesis. At least not to me. Although others have advanced possible explanations, I do not. All I can offer is observations. By all means, look up other peoples' proposed mechanisms and discuss them. Some make more sense than others, but it's certainly not a fixed thing where everybody agrees that it's because of such-and-such.
Incidentally, the effect is certainly not new as someone said above. I don't recall seeing anyone say that it's new in any way, shape, form, or fashion. I first ran across it in about '81 or '82, and it was known long before then.
The same poster is guilty of using science as religion. The "If it were real, they'd be doing it at NASA" argument is old. Essentially, he's appealing to an authority figure (aka god) to smite the infidel. Science does not rely on authority figures and invariate revealed truth. It relies on observations of phenomena, followed by hypotheses, followed by tests. To assume that everything is known at any given point in time is the height of arrogance.
As for evidence, I will repeat what I said earlier, if you are familiar with the effects of absolute phase, and if your system (and, I suppose, your hearing) is such that you can hear that, then listen. What could be simpler? It's on about that same level or degree or whatever you wish to call it. The only remaining variable is whether your system is up to the task. I wouldn't care to try it on a gain clone-based system (sorry, Peter), but the effect has been obvious enough on a lot of other systems.
People always whine and carp about this one, too, but I'll throw it in. Back when I was in retail, we got in a shipment of cables from the Vampire Wire folks (Sound Connections). Steve, a fellow who worked with me at the time, got busy listening to the cables. It was a service we provided. Didn't charge for it--it was just something to do on slow afternoons. We had a red marker that we used to put a dot on the leading end of the cable. He couldn't find it and made do with a black one. I'd been off that day for some reason, but came in the next day and saw the cables. I didn't see red and assumed that they were unmarked. I managed to locate the red marker and sat down with the same cables. Marked them with the red marker. The next day, Steve was back and I mentioned that the cables were done. He said, yeah, he knew, he'd done them. At which point he showed me his black dot, which I had missed.
The punch line? There were twenty pairs; forty individual cables in all. Steve's black dots and my red ones matched perfectly on every cable.
Was that "scientific" enough? No, of course not. Not controlled. Not single, double, triple, quadruple blind. Not ABX. Not...fill in the blank. For those who have made up their minds already, no amount of evidence will convince them that something as odd as cable directionality exists. On the other hand it does rather strain the statistics of chance, does it not? Neither of us had any vested interest in the outcome. We didn't have any external guide on the cables themselves, as this was before people started marking cable jackets with arrows. Even the writing on the jackets had proved to change from time to time--seems that the manufacturer just marked it any old convenient way--so we had no indication there, either.
I'll say it again. It's weird. It's annoying. It's counterintuitive. But it's there.
Grey |
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| Bratislav |
| quote: | Originally posted by GRollins
The same poster is guilty of using science as religion. The "If it were real, they'd be doing it at NASA" argument is old. |
Really ? So you can sideswipe all scientists (NASA isn't at forferont of technology in many fields anyway, including ultra low signal detection - observe who made the critical instruments on SOHO, HST etc.) and simply offer non controlled personal experience for a fact ?
Accuse me of "scientologism" (or whatever your word for sci-religion is), but in my books fact and fiction don't sit on the same page. There are thousands of PhD's written RIGHT NOW on various aspects of signal detection, including cabling/impedance/dielectric/shielding/whatever effects. To assert that noone has thought about directionality is ludicrous. For Chist's sake, people have FALSIFIED data to get into scientific history - do not underestimate scientists' drive to "boldly go where noone went before". If there was one iota in this, there'd be articles everywhere (and I'm not talking audio magazines here - only peer reviewed stuff counts. That is religion of science, sorry).
BTW, talking about "old arguments" - the one where only certain people have "systems" that offer resolution good enough to hear these effects comes to mind rather quickly.
Bratislav |
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| phn |
| I think I know what absolute phase is. Again, I have never said that stuff doesn't matter. (I'm getting a bit tired of having to answer stuff I have never expressed an opinion on.) A ferrite core on a cable makes a difference. Hence, the Transparent box does make a difference. But that's it. It's all physics. There are no magic powers in the Transparent box, no hoodoo, no witchcraft, no nothing despite what Stereophile and rest of the mouthpieces in the high-price audio press try to tell us. Here's a gutted Music Wave cable. The demons have been exercised. |
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| SY |
"Exorcised." Unless they're muscled demons.
I can't remember whose cable it was, maybe MIT, but Audio Critic opened up the sealed boxes on each end and found in one box... nothing but the potting material and in the other, a 100 ohm resistor shunted across the two leads. One could argue that the shunt resistor could have some microscopic but oh-so-important effect...
GR, interesting anecdote. Thanks. |
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| Yoghourt |
If
- cable has directionality
- and result is audible while playing music
then
- feed the same audio signal to 2 cables having different directionality but otherwise being the same, including cable construction (shield structure or whatsoever)
- probe the 2 toutputs
- check difference between the two probes
end
Get ready for major headaches in order to sort out difference signal from experiments noise and measure errors, especially knowing that differences must be searched from DC to amplifier's internal bandwidth, generally above MHz.
Question is: is that the "20% of causes" that will solve the "80% of consequences" in the quest to audio perfection? In other words, are all other items of the audio system (including recording sub-system, the listening room, and the guys who listen) already so good that the "directionality of cable" supersedes all other possible improvements? |
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| phn |
| The Transparent cable was apparently not much better. One of the components, if I understand it, was hanging. It was only connected at one end. I'm not sure, but the function of the Transparent box may in fact be to keep capacitance consistent regardless how long the cable is. Somebody on that forum said something such, if I remember. Take that for what it is, a wild speculation on my part. But I know that you shouldn't shorten some factory terminated cables if the values, like for a cartridge, are important. Having that said, the really funny part about all this is that people seem to believe the cable manufacturers sit on some big secret the rest of the world don't know about. Actually, it's not so much fun as tragic. |
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| runebivrin |
| quote: | Originally posted by phn
The Transparent cable was apparently not much better. One of the components, if I understand it, was hanging. It was only connected at one end. |
As it turns out, the actual connection was a Zobel network with 1nF in series with 26.7 ohms, and two mysterious thin conductors connected in one end only with one of the main conductors. This may result in a minute directionality; I'm not up to the maths of this (actually too lazy). Higly scientific, and active somewhere in the region of 5.5 MHz and above, if I got the decimals right. Incidentally, 5.5 MHz is the audio sub carrier in the PAL colour TV system. Are they on to something?:D
Rune |
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| GRollins |
The cables I have mentioned were all un-terminated.
It would be interesting to take something like an MIT cable which is marked with a direction and listen to it 'backwards.'
It might also be interesting to remove the termination items from a terminated cable and listen.
Yoghourt's proposal is interesting, but will not convince anyone who has already made up their mind that there's nothing to this, as they'll claim imbalances in the differential going into the scope or other test equipment.
I wouldn't anticipate finding anything very useful using sine waves, so I propose using music and some sort of nulling hookup, then look at the residual. Of course, the problem then becomes: How does the non-test signal get to the summing device? Through another cable, of course. Ugh. Okay, maybe this will be more difficult than I thought.
I would be surprised indeed if the differences were any greater than, say, -40dB. It will take a certain measure (ahem) of sensitivity in the test instruments to find anything; i.e. don't bother trying to see anything with a multimeter.
I've just had an idea relating to the cable shielding, but I want to think it over for a bit before I toss it out for public mauling.
Grey |
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| Bratislav |
| quote: | Originally posted by GRollins
How does the non-test signal get to the summing device? Through another cable, of course. Ugh. Okay, maybe this will be more difficult than I thought.
|
Well, you can have calibrated termination devices (say two identical 100kohm resistors) placed physically close to the measuring device (say high end CRO) and run two very short runs of single wire (ultra low capacitance/inductance) straight into two inputs from the "top" of the two resistors. Run "A-B" and there's your residual. You can probably place one end of the resistor straight into the input, so no extra wire involved.
| quote: |
I would be surprised indeed if the differences were any greater than, say, -40dB.
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I would be really surprised if residuals are anywhere near -100dB.
Typically cable residuals are well into -150dB range. |
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| Bratislav |
| quote: | Originally posted by Bratislav
Well, you can have calibrated termination devices (say two identical 100kohm resistors) |
I just relized people have mainly been talking about speaker cables (right ? there's no much sense placing a 100 Ohm across the leads of line level cable), I've been carried away with another experiment (long story). In which case use your calibrated speaker loads (8ohm in paralel with 1 uF or whatever is your fancy; but use impedance bridge to make sure terminating impedances are EXACTLY the same) and do the same as above.
Bratislav |
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| Yoghourt |
| quote: | Originally posted by Yoghourt
- feed the same audio signal to 2 cables
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| quote: | Originally posted by GRollins
I wouldn't anticipate finding anything very useful using sine waves, so I propose using music |
I had not talk about sine waves...
| quote: | | indeed if the differences were any greater than, say, -40dB. It will take a certain measure (ahem) of sensitivity in the test instruments to find anything |
-40dB? Easy for an high impedance differential amplifier (aka an instrumentation amplifier). With a proper setup, one can probe for differential signals 80 to 90dB below common mode signal, with 1 megohm input impedance. Basic info on it is typically found in fast AOP datasheets. |
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| real |
Guys,
I am just wondering, even if cable directionality does exist (which I must say I completely disagree with), how can it matter for audio, since audio is AC - half the time it will be going in the 'better' direction, the rest of the time it will be going in the 'bad' direction.
Also, if the cable has some effect on the signal, think about how the cable is connected to your system. Since we are talking about such tiny variations in the signal here (don't say it's not minute [if it's there]) then what effects will the slightly different connections to the amplifier, speakers have each time you swap over the cable ends to check for the 'right direction'? On such small scales as the 'cable direction' then surely this will have an effect too, not to mention all other uncertainties (bit error from CD player in one test but not other)? Do they not matter?
I'm interested in any replies.
Chris. |
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| Circlotron |
I don't believe cable directionality exists.
Therefore, I am unable to hear it.
I imagine the opposite would apply also.
Makes it kind of hard to nail down. :rolleyes: |
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| mikelm |
| quote: | Originally posted by real
I am just wondering, even if cable directionality does exist (which I must say I completely disagree with), how can it matter for audio, since audio is AC - half the time it will be going in the 'better' direction, the rest of the time it will be going in the 'bad' direction. |
Hi Chris - yes in one sense the signal is going equally backwards & forwards but in another sence an electromagnetic signal is going from the i/p end to the o/p end.
It is this second scenario - I believe - that may explain directionality.
any other thoughts on this idea ?
mike |
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| phn |
DOOH!!
Finally got your post.
Exercised.
Exorcised.
That I get for being a terminal insomniac and posting here way past midnight. Damn second language.:D |
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| janneman |
| quote: | Originally posted by mikelm
Hi Chris - yes in one sense the signal is going equally backwards & forwards but in another sence an electromagnetic signal is going from the i/p end to the o/p end.
It is this second scenario - I believe - that may explain directionality.
any other thoughts on this idea ?
mike |
Mike,
I don't understand the logic here. If the signal alternates in two directions, and the signal generates the electromagnetic signal, doesn't it follow that the electromagnetic signal, or rather the electromagnetic field, also alternates in the two directions?
Jan Didden |
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| Yoghourt |
Even if signal is AC, you have the signal source at one end of the cable. :clown:
AC electromagnetic field is *propagated* from that source.:D |
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| janneman |
| quote: | Originally posted by Yoghourt
Even if signal is AC, you have the signal source at one end of the cable. :clown:
AC electromagnetic field is *propagated* from that source.:D |
Hi Danone,
I think that only goes for cables that are long in relation to the wavelength. With shorter lengths, both the signal and the field (which are two manifestations of the same phenomenon) are stationary. If what you say would be true, it would also mean that the signal is "propagated" from one end to the other. In the limiting case that is true, but does not come into play except with either very high frequencies or cable lengths of many miles.
But all this talk really leads us away from the topic. Whatever the propagation is, there is no indication that it would suddenly be different when you change the cable direction.
Jan Didden |
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| GRollins |
I think you've overlooked an important point. Signals that are going back-and-forth, with the implication of complete symmetry are called sine waves (okay, cosine, triangle, square etc. are symmetrical too, but that doesn't invalidate my point). We don't generally listen to sine waves, we listen to music.
Music is asymmetrical. Take an extreme example like a drum. The impulse will spike hard as the drum is hit, then damp rapidly. Do a little analysis and you'll find that much more current (i.e. the area under the curve) is flowing one way than the other. The result is a net current flow that does not return. The "AC just goes back and forth and thus evens out" argument is a red herring...unless you intend to listen to sine waves.
Grey
P.S.: This leads me to wonder if there's a way to use Fourier analysis to isolate the effect. |
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| Yoghourt |
Jan: for info, propagation always exists (Maxwell equations + causality). When we consider that U and I are constant, we in fact consider that the setup of U and I is so fast that it's useless to even think about it. (end of off-topic :) )
Grey: if there is more "forth" than "back", then it means that you are feeding your speakers with DC current...
Music is not symetrical, but average (integral) of signal "envellope" (sorry, I don't find the english word for it") is supposedly 0. Not even talking about Fourrier decomposition of signal into sine waves ;)
If metal crystallin structure is not symetrical, then one could argue that parasitics encoutered by current are not the same when current goes "forth" and when it goes "back". Same idea for insulator. A collegue thought about twisting orientation, as far as twisted pairs are concerned.
But question is: can one prove objectively that cable directionality has audible impact? |
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| Bratislav |
| quote: | Originally posted by Yoghourt
But question is: can one prove objectively that cable directionality has audible impact? |
Of course we can ! If we accept that is ELECTRICAL signal differences that have to be responsible for audible differences (speakers being electromechanical devices), comparing the shape of the electric signal at the terminating devices (which HAVE to be the same), one cable having direction reversed, is relatively trivial. This is a highly sensitive test (null test).
Then we can start arguing whether residuals 100dB+ below signal are audible or not, and start spectral analysis of the residuals (are they low or high level THD, nonlinear, transient, whatever).
If we venture into "not yet known quantum mechanisms or whatever", then no, we cannot objectively prove anything.
Bratislav |
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| hummhoom |
| I'm unaware of any cable directionality occuring, even at the -100dB level. Metal oxide to metal junctions can rectify though, this is the basis behing the silicon rectifier. |
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| jcx |
| quote: | Originally posted by GRollins
I think you've overlooked an important point. Signals that are going back-and-forth, with the implication of complete symmetry are called sine waves (okay, cosine, triangle, square etc. are symmetrical too, but that doesn't invalidate my point). We don't generally listen to sine waves, we listen to music.
Music is asymmetrical. Take an extreme example like a drum. The impulse will spike hard as the drum is hit, then damp rapidly. Do a little analysis and you'll find that much more current (i.e. the area under the curve) is flowing one way than the other. The result is a net current flow that does not return. The "AC just goes back and forth and thus evens out" argument is a red herring...unless you intend to listen to sine waves.
Grey
P.S.: This leads me to wonder if there's a way to use Fourier analysis to isolate the effect. |
this makes about as miuch sense as setting off explosives in sealed rooms - which is the olny way i can concieve of getting a DC component in a sound wave |
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| janneman |
| quote: | Originally posted by Bratislav
Of course we can ! If we accept that is ELECTRICAL signal differences that have to be responsible for audible differences (speakers being electromechanical devices), comparing the shape of the electric signal at the terminating devices (which HAVE to be the same), one cable having direction reversed, is relatively trivial. This is a highly sensitive test (null test).[snip] |
Yes indeed. We must remember, as you said, that ANY audible difference MUST come from a different electrical signal at the amp terminal. Unless you believe in ESP (sorry Rod).
The argument often is that the electrical difference is too small to measure but the audible effect can be readily heard. I have no clear answer to that, but there is some VERY sensitive equipment out there, that is more sensitive than our hearing, like 120dB+ dynamic range. Also, they say that what we measure would be the wrong thing. But hell, ANY measurable difference that corresponds to an audible difference would be a step forward.
So, my considered opinion is, that if there is an audible difference, it should be electrically measurable. But no, I have no proof of that.
Jan Didden |
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| mikelm |
| quote: | Originally posted by jcx
this makes about as miuch sense as setting off explosives in sealed rooms - which is the olny way i can concieve of getting a DC component in a sound wave |
Are you so sure ?
If a drummer hits the bass drum pedal good and hard and then releases the pressure very slowly...
the forward stroke is heard and felt as a transient but the reverse stroke could well be out of band i.e. the signal will not even reach the amp.
The speaker will return to rest position but not because a signal from the amp. The average of what the amp did was not zero |
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| scott_jcp |
| You anaolgy about the drum being hit is ridiculous. When the drun is first hit, the sound you hear is a the waveform of the sound.... a series of up and down peaks in air pressure (which corresponds to up and down peaks in the voltage of your signal cable). As the volume of the noise of the drum being hit falls, the amplitude of this wave decreases, but is still averaged around 0. If the wave was centered above a zero amplitude, you wouldn't hear anything--since we hear tone based on the frequency of a tone, it must be a continously oscilating pressure/single wave. ie. A "spike" on only one side of zero that does not cause an oscilation at a particular frequency is inaudible. |
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| Bratislav |
| quote: | Originally posted by janneman
Yes indeed. We must remember, as you said, that ANY audible difference MUST come from a different electrical signal at the amp terminal. |
Jan,
I believe you meant at speaker terminal. If cable directivity is somehow "modifying" the signal originating form the amp, differences should only be visible at the terminating end. In any case, this is where we should measure/compare.
As you said, we have already at our disposal equipment that will measure voltage differences at microvolt level - easily. State of the art devices will go several orders of magnitude below that.
And then we have the question on how small the signal can get before speaker doesn't react to it AT ALL. No cone movement, no detection by even golden ears. Unless we get into ESP again ...
Bratislav |
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| SY |
Take a mike and a scope, go to a bass drummer, and try looking at the waveform.
For a better example of an asymmetrical waveform, mike a trombone. Instruments like that are useful when you're playing with absolute polarity. |
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| GRollins |
Thank you, SY. I was beginning to wonder if anyone here had ever bothered to look at a real musical instrument waveform before.
Based on the posts above, it would seem that there are few who have. If there is such a high level of, well, ignorance about the physics of music, then it's no surprise at all that this discussion hasn't moved forward.
Incidentally, the more-or-less symmetrical, decaying waveform described above will give a nice, clear tone much like a bell. It sounds nothing whatsoever like a drum. In fact, if you actually draw the waveform, even a rudimentary analysis will show that it, too, is assymetrical. Higher math is not required, only a pair of eyes. Each peak (positive, then negative, then positive again...) is less than the opposite polarity one that preceded it. Ergo, it does not have the same area under the curve, and the result is not a zero sum solution. At the end, the polarity that produced the initial peak will win the current flow sweepstakes.
It's not difficult to build a circuit that will produce such a waveform. Try it sometime. A drum, by definition, produces an asymmetrical waveform. It is possible to build a circuit that produces a noise somewhat like a drum, but SY's mic & scope suggestion will give you a much more realistic understanding.
For those who assume that a waveform must be symmetrical to be audible, imagine the following: Speaker cone at rest, speaker cone jumps forward, speaker cone returns to rest position (i.e. 0V) without ever moving backwards.
Did you hear something? Yes. What did it sound like? Well, in a crude sense, it sounded like a bass drum, though it lacked overtones.
Grey |
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| mikelm |
| quote: | Originally posted by scott_jcp
You anaolgy about the drum being hit is ridiculous. When the drun is first hit, the sound you hear is a the waveform of the sound.... a series of up and down peaks in air pressure (which corresponds to up and down peaks in the voltage of your signal cable). As the volume of the noise of the drum being hit falls, the amplitude of this wave decreases, but is still averaged around 0. If the wave was centered above a zero amplitude, you wouldn't hear anything--since we hear tone based on the frequency of a tone, it must be a continously oscilating pressure/single wave. ie. A "spike" on only one side of zero that does not cause an oscilation at a particular frequency is inaudible. |
If you hit the bass drum pedal on a regular rock & roll drum kit and hold your foot down the skin of the drum is pushed forward, damped by the soft hammer and held in place by the pressure of the drummers foot on the pedal. There may be some side vibrations but the majority of the movement in the skin moving forward and staying put.
I was not talking about timpani !
So not that rediculous...:) |
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| mikelm |
| quote: | Originally posted by SY
Take a mike and a scope, go to a bass drummer, and try looking at the waveform.
For a better example of an asymmetrical waveform, mike a trombone. Instruments like that are useful when you're playing with absolute polarity. |
Well yes, but with the drum you do not need the scope, the movement can be clearly observed ( although using the scope might be easier on the ears ! )
True though this is, to be honest it is probably not helping our understanding of cable directionality...;)
mike |
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| SY |
| Hmmm, the scenario you propose won't pass the continuity equation test. You can't create pressure that integrates out to anything other than zero unless you have an airtight room with a bass drum membrane stuck on one wall with it being pushed from the outside and not let go, i.e., a more-or-less permanent volume change in a sealed room. |
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| SY |
| Mike, the idea is that if there's any sense to the directionality stuff, one would predict that asymmetric waveforms like trombone would be the most useful for detection. |
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| mikelm |
| quote: | Originally posted by SY
Hmmm, the scenario you propose won't pass the continuity equation test. You can't create pressure that integrates out to anything other than zero unless you have an airtight room with a bass drum membrane stuck on one wall |
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