While there is good information in that thread, maybe a few posts, most of it is a disaster, and pretty much none of it matters at audio bandwidths. Transmission line effects are not relevant at audio bandwidths and cable lengths except poorly matched digital cables and connections. Bulk effects would be far more relevant and there would need to be directional differences large enough to make a difference. There are many reasons cables can be directional and that thread only covers one really, but huuuge difference between reasons and MFG differences large enough to have any potential ability to be audible.
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Uhmmmm, most copper wires for flexible cable is annealed, which does cause recrystalization and improves conductivity, but importantly also makes it softer and more workable (and less likely to break). Some copper wire is intentionally not annealed to make it more difficult to hold a bend and increase tensile strength. Really, this is not a debatable item. It is done day in and day out and is well understood.
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This is an apples and oranges thing. This is a digital signal with very fast edge speeds, using RCA jacks. RCA jacks are not impedance controlled, and we have no idea whether any attempt at edge speed control (or termination) was implemented on the transmitting end to reduce reflection due to edge speeds that could have GHz components, unlike the 20Khz (ish) for analog audio. Al, (almarg), pointed out some where in the article, or a foot note,
there is a follow up saying the directionality was due to the
differences in the amount of solder used on one RCA connector than the
other. Was it the solder? Beats me.... I remember that Stereophile article, and skimming it, remember some glaring errors, like claiming the DTI magically improves the jitter from the DAT deck, a conclusion that cannot be reached, because all the previous tests with the jitter tester showed, is that the jitter with the DAT and the jitter tester was high, which could (and most likely is) an incompatibility between the DAT and the jitter tester (including the cable), not necessarily high jitter in the DAT itself. Low driver level on the DAT output (possibly to be compatible with something else), and a high threshold voltage on the input logic of the jitter tester could have made it overly sensitive to reflections on the cable, which seems sort of self-evident given the significant difference in jitter by changing direction. Definitely some bad stuff going on there, at very high edge rates with non impedance controlled connections (hence the reason to move to BNC). |
I don't know, where are you from geoffkait?
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Assuming I have the correct Ted, that is probably an insult to Ted ... Bundy :-) I assume Ted Bundy. |
Mr. Geoffkait, I don't think it best to quote HowItWorks articles that poorly quote Wikipedia. The result can be less than coherent. Take this sentence, The voice coil's electromagnet is placed within a permanent magnetic
field. The two magnets interact, and every time the electromagnet's
polarity changes, the interaction between the magnets changes. The voice-coil is the electromagnetic, and the voice-coil's magnetic field interacts with the permanent magnet field. Perhaps that is what they meant, but you get the impression they didn't really understand it. The signal energy travels down the cables in one direction
>>>> from the source to the load, (amp to speakers), in the
form of an electromagnetic wave. That is not really true and is shown not to be true with a simple case, a DC voltage and a load. There is no continuous electromagnetic wave to transfer energy. What there is is an electromagnetic field that cause electron movement with causes a magnetic field. The product of those two (power) always points to the load which is the direction of power transfer. In a transmission line, the changing e-field causes electrons to move which propagates down the cable as an electromagnetic wave, but technically, other than losses, no work is done. The "wave" sets up the fields, but does not define the transfer of energy ... at least using classical EM theory. |
Don't ask me, I can't even get it out of the roll without putting a ton or kinks in it ;-) Oh crap my home depot wire is not marked with the direction I should
install them. Does anyone know which direction will work best? I'm
freaking out here. |
And if you are late on a customer deliverable, they will travel anywhere but where you want them to be. In digital circuits the signal and energy travel in the
spaces between the traces or between the traces and the conducting surfaces. ... but I digress. The energy travels primarily outside the conductors as that is where the fields are, but the fields are a function of the properties of the conductors and the dielectric. |
Also, the way I always see the skin effect stated, the “high frequencies” travel nearer to the surface - but not outside the conductor - whereas lower frequencies travel closer to the center of the conductor.
Is that completely wrong?
Not wrong, but not accurate either. Electrical field penetrates conductor, moves charges, induces magnetic field, but the majority of the fields are outside the conductor, and the product of the fields, the power transfer is near 0 in the conductor. At high frequencies, the electrical field does not penetrate very far into the conductor and hence the charge only near the surface of the conductor moves. The fields are still mainly outside the conductor and again, the product of the two fields (power) is near 0. |
What difference? - If the difference is not frequency dependent, or at least the dependency on frequency is small within the audio frequency band, then the impact of crystal structure would be akin to changing wire size. - I am not aware of any non-linearities w.r.t. crystal structure either that could cause distortion, and there does not appear to be any energy storage mechanism of note either. Where I am aware of crystal structure being an issue is at extremely high current densities allowed when temperatures reach superconducting levels. Making a difference, and making a difference that is anywhere near the realm of audible, are the critical discussion points. I am not going to be able to tell the difference between a 1lb and a 1.001lb weight in my hand, though it can be easily measured. Why wouldn’t the non-symmetrical crystal structure of drawn wire also
make a difference in the signal transmission? Especially if the non
symmetry was visible on the surface of the wire. Yes? No? |
While Ralph Morrison is not the last word on electromagnetism, I am not questioning his expertise, because I did read your links (and have one of his books), and there is nothing in them that disagrees with what I wrote Jea48. I am not questioning Ralph Morrison's understanding, I am questioning yours. Why would I read the other thread you linked to. With the exception of almarg who always writes clearly, it is mainly a miss-mash of misconceptions and partial truths and I have better things that go through it in detail. How much energy is outside the conductor and how much inside the
conductor? If it 80% - 20%? Maybe 50% - 50%? 95% - 5%? If most of the
“energy” travels outside the conductor please explain all the heartburn
over skin effect, for which very high frequencies travel closer to the
surface and lower frequencies travel deeper inside the conductor. Also,
frequencies of what? Thanks in advance. Almost all the energy is outside the conductor. The product of the electric field and magnetic field inside the conductor is near 0, assuming a good conductor. The E-field penetrates the conductor causing charge to move inducing the magnetic field, and with high frequency, that e-field does not penetrate much into the conductor, but in either case, almost all the energy is outside the conductor. |
So, you believe the “audio signal” travels inside the conductor, right?
Regardless of whether the skin effect applies or not. I’ll ask again,
the frequency of what? It's moot where the "signal" moves, what matters is if the effects are relevant at the frequencies of interest in the system in which they are installed. All cables in a given system will have some directional aspects at high enough frequencies, but a 10 foot cable at 2/3 the speed of light means the signal takes 10 nanoseconds from the amp to the speakers, and neither the amplifier nor the speaker are a set impedance, and they certainly are not "matched". Any transmission line effects will be 100's of db below the signal. So what else could be "directional"? Pretty much all that is left, absent intentional directionality (i.e. added RLC elements), is differences in lumped bulk RLC parameters based on the direction. However, the bulk RLC of any half-decent cable should be such that frequency dependent impact on transmission is a fraction of a db, meaning also no detectable phase shift by any human on the planet (we are terrible at detecting phase-shift that is the same on both channels), and since directional changes in the bulk RLC are orders of magnitude less that the bulk RLC, that fraction of a db now becomes thousandths of a db .... obviously undetectable. It's fine to talk about single crystal copper (which improves by high temperature annealing, not cryogenic processing, but I digress), and it is recognized to have better conductivity at low frequency, there is no evidence of any frequency dependent effects that could impact audio transmission. |
You may be sure, but I think most others would find it to be a equivalency that is not false. It illustrated the difference between factually different, and detectable by human alone different, which is the argument on any cable directionality discussion. I would never take the position that all cables are not "directional" at a high enough frequency in a given system as there will always be a high enough frequency, for a given length, and a large enough signal to noise ratio that they will be directional. I take the position, that within the sphere of human detectable audio difference, they are not directional. As I have yet to see anyone measure a significant enough difference, factually illustrate how there could be a significant enough difference, or show, in reasonably controlled conditions, an audible difference (including ones I have ran), I have had no reason to change my position. If someone want to believe there is and plays around with it, I am not going to stop them, but I would point out that repeated removal and connections of wires is often a good cleaning process, and for interconnects, rotating the RCA can help with this as well.
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Me thinks Nordost marketing people come to audio forums for inspiration ;-)
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Geoff, nice to see you still have your square peg this morning. Same hammer?
Andy I think L1 and L2 would have been enough. |
Yup, same hammer, different square peg. At least you are consistent ... or is that predictable?
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