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Hi !
i am trying to understand a little about cables science.
I found the interview in the link but there is a point that i do not understand.
If i am not wrong the designer talks about a difference in the signal speed through the conductor and through the dielectric, causing a time disalignment of the two signals, if i have understood correctly of course.
And he says that they have found a specific metal alloy for the conductor to reduce the speed in the conductor and align it with that in the dielectric ?
However ... my question is pretty basic and maybe very trivial, i am a beginner.
Does a signal travel in a dielectric that, by its nature, is not conductive ?
How is it possible that a signal, that in the end is a voltage, can propagate through a dielectric ?
what i am missing ?
Thanks a lot indeed for any welcome and appreciated advice.
Kind regards,
bg
Edits: 04/19/15 04/19/15Follow Ups:
R&D department are the guys laughing all the way to the bank!
Hi i think that is a case of difficult communication.
I have a great admiration for the actual products and consequently for their designer/manufacturer.
They deliver IMHE a very musical and nice sound, especially when used with digital sources. They tend to make digital sound right.
I would like very much to understand what makes them so nice.
In the past i had a very little DIY experience with simple twisted magnet wires.
I heard something extremly interesting but also quite unbalanced.
Now i think that solid core wires have a lenghty break-in and with a little more patience i am quite sure even those simple wires could deliver a good sound.
And of course in that case the dielectrics where the thin layer of enamel and the air between the conductors.
I am a believer in solid core/litz wire interconnects (less for speaker/power cables, much less).
I hope to get a confirmation this weekend after some tests.
And midrange is the key. If the midrange is right that the rest can wait.
Kind regards,
bg
Edits: 04/24/15 04/24/15 04/24/15 04/24/15
It might help to take a different look at exactly what the audio signal is.
It is an electromagnetic wave traveling through space, with magnetic and electric (voltage) components that are intertwined and inseparable.
The wires could be looked at as simply a sort of "guide" for the EM waves to most easily travel near.
Another thought is that if you had a perfect superconductor, then virtually NONE of the signal would actually travel INSIDE the wires, but rather, be right at the surface and in the surrounding space around and between the wires.
Even with "ordinary" conductors, almost all of the voltage field is outside the wires in the dielectric, and most of the magnetic fields are outside the wires in the space between the wires.
Thus the dielectric material used to insulate and separate the two different polarities of wires has a much greater influence on the sound than one might otherwise believe.
The velocity of signal propagation is directly related to the dielectric quality of the surrounding insulation, as this insulation has a direct and significant effect on the propagation of the voltage signal through space.
A really poor insulation can slow the VOP down to nearly half the speed of light, while a superb and well engineered insulation can do better than 80-90% the speed of light for the VOP.
It can be hard to comprehend some of the tenets of high performance cable design, but a solid and well versed basis in physics and EM theory and practice can provide a means to understanding many of the advanced and esoteric concepts used for high performance audio cables.
Jon Risch
reflectometers. They send a pulse down a cable and measures the reflections. They can determine how far down the cable the issue lies. For cables like a cat 5, a sharp bend, or an over tightened zip tie can make a measurable difference.
In hindsight, (no I don't have one, but placed a bid for several at DRMO auctions), the issue may not be the wire itself but must be the insulation, too.
Jon,
That is the best explanation of the contribution of dielectric material that I have read to date. This is the first time that I feel I understand how it works. Thanks!
Dave
.
Hi and thank you very much for your very kind and valuable advice.
I have to say honestly that i understand much better your words than the mentioned interview. Your words make sense.
I understand that some kind of proprietary technology or invention is involved.
Nevertheless i have found the explanation in the interview very obscure.
However, i would like to take the opportunity to ask you why most of the unbalanced cables (not XLRs) are twisted pairs plus screen instead of a simple coaxial.
I have the feeling that a well designed and built coaxial should be absolutely perfect for unbalanced connections.
Why they are not more popular ? They would be my first choice.
Thanks a lot again.
Kind regards,
bg
RE twisted pairs vs coaxial cables carrying audio signals.
You need to realize that the so called ground leg carries the signal every bit as much as the so-called "hot" wire does.
See:
About cable "ground":
http://www.AudioAsylum.com/audio/cables/messages/503.html
With that in mind, the real world coaxial cable often has a foil layer, or tinned conductors, or silver plated conductors, or some other less than ideal conductor situation.
The outer layer of a coax (the "shield") often uses a completely different gauge wire than the center wire, woven at a significant angle, with wires criss-crosssing each other to form the tubular coax outer layer.
This leads to an imbalanced amount AND length of conductive material, as well as an imbalance in the voltage field gradient at the surface of the conductor compared to the center wire.
The magnetic field density is also different than the conditions present at the center wire, thus, the magnetic field lines are not balanced either.
Thus the audio signal has to traverse two different kinds of paths to make the round trip that is necessary for actual signal transfer from the source to the load.
With a twisted pair, the audio signal has the same type of wire to traverse, the same electrical and magnetic field conditions for both signal paths, and the close proximity and twisting help provide some small degree of outside interference rejection even though the cable may be an "unbalanced" electrical situation (as opposed to a true balanced condition).
Finally, with a separate shield structure present to help ward off outside
interference, the audio signal "ground" leg does not have to also carry away the interference signal as well as to pass the audio signal. Note that when a shield is forced to carry current, it's shielding effectiveness is reduced and compromised. By the same way, draining the outside interference into the audio signal ground by directly mixing the two in the same conductor is NOT a good thing.
The separate shield of a twisted pair prevents this from occurring, and thus avoids the contamination of the audio signal with outside interference as much.
These are admittedly small issues, and usually have a minute influence on the total resulting sonic performance. However, they ARE positives compared to the coax situation, and all these things add up.
Of all of them, the slight added amount of outside interference rejection may be the most important, as it is hard to overstate the deleterious effects of such contamination of the audio signal on a high performance audio playback system.
Jon Risch
Hi Mr. Risch,
thank you sincerely for the very valuable advice.
Even if i am very uneducated this makes a lot of sense to me.
However, i still have some big doubts.
Let me elaborate a little.
One thing that i have learnt here is that digital signals transmission is usually a very challenging task.
So i am doing a weird reasoning.
If this task is more demanding that the transmission of an analog signal why good digital cables (usually coaxial) cannot be also good for analog signals ?
Moreover one of the most challenging situation is the connection from a scope probe to the scope.
So a cable good for a scope probe should be also good for digital connections (impedance issue solved) and then also for analog connections.
But i guess i am trivializing a lot.
There could be something more decisive involved.
Thanks a lot again for the very valuable advice.
Kind regards,
bg
Your logic chain is not completely valid.
Oscilloscope cable use is not the same criteria as digital cable use, which is not the same criteria as analog signal use.
Without going into all the nitty gritty, as this would take some time to do, and I have posted many posts on audio cables and the theories behind the quality issues, I will give one set of examples for comparison.
In the case of an SP/DIF digital connection, the factors that make for good clean transmission of digital data are different than those for analog signal transfer.
For instance, the main factor for a digital cable is helping to maintain a low jitter signal environment.
This requires tremendous bandwidth, well above the fundamental data transmission frequencies centered around 5 MHz, good shielding and freedom from external noise and interference, and a controlled impedance
environment.
Analog signal transfer has a different set of important factors, good signal resolution at extremely low levels in the uV region, while digital needs to be clean in the middle of the bi-phase signal waveform, where the accurate timing detection of a signal polarity flip is paramount, that occurs around the middle of a 0 to 5 volt range.
Analog does not need a 60 MHz bandwidth or higher to convey high performance audio signals.
Analog signal transfer does not require strict and consistent impedance conditions at the source, along the cable, or at the load.
There are many other factors that come into play for each type of cable, but to say that a cable that performs well for digital or scope use will also perform well for analog signal transfer is an erroneous idea.
Jon Risch
Hi and thanks a lot again.
I was looking for a free meal ... almost let's say.
Because making a good digital cable appears quite straightforward to me.
I nice coaxial (like the Belden or VHAudio ones) and a decent pair of RCAs is what is needed.
But i have not carried-out many comparison for digital.
Instead i have tested many different analog Ics in the same system and i have been amazed by the differences.
With some Ics the sounds were all disconnected, while the good Ics put everything in order, like when focusing with a lens.
The fact that cables fascinate so many people i think it has to do with these effective differences perceived during the listening.
Thanks a lot again.
Kind regards,
bg
Edits: 04/23/15
Rather than "slowing down" the conductivity of metal wires, I think George Cardas is talking about his insight into a new cable geometry that affects how signal energy is propagated along the length of the conductive metal wires, as well as how the signal energy is propagated within the non-conductive dielectric, since like a capacitor, the dielectric of an audio cable acts as an energy storage reservoir, and the behavior of the dielectric greatly affects what comes out the load end of an audio cable.
My impression of what he is saying, is the storage and release behavior of his newest dielectric material(s) is paramount when designing a specific cable geometry that provides a more "time aligned" velocity of propagation between the dielectric involvement factor, and the electromagnetic fields of complicated, precision wire bundles, rather than just paying attention to that of skin effect, and the resonant behavior of litz-wire.
Hi i was thinking ... in a cable of let's say 2 meter length which will be the difference in time arrival between a signal running at the speed of the light and a signal running at 1% of the same speed ?
The human ear will be able to differentiate ?
Just asking.
Thanks again.
Kind regards,
bg
Edits: 04/21/15
US7674973
He is contending that the signal VoP is mismatched between the dielectric and the wire there for causing sonic degradation. His solution is to lengthen the conductor to a point VoP would be the "same" between the two.
I think it is a solution to a none issue though. VoP of a insulated wire is just that, the wire and dielectric together, not a separate VoP for dielectric and that of the wire it is insulating. Without an internal conductor a dielectric would propagate nothing.
Hi and thanks a lot for the very kind and interesting explanation.
I understand more clearly now the complexity of the phenomena and their comprehension is very challenging for me.
My skills are very limited.
But i get that he is talking about the dielectric composition. Good.
Cables in a way are like long capacitors and dielectric quality is very important in capacitors and i guess the same in cables.
Thanks again.
Kind regards,
bg
There are seeming contradictions in the video. If the dielectric carries the signal at 78% of the speed of light (?, IIRC), and is faster than the conductor, then it sort of ignores the rational scientific basis of resistivity of materials, which ranks silver as #1 closely followed by copper. Most plastics are not even close.
I firmly believe that Cardas had something else in mind, otherwise why bother with the conductor and simply use the dielectric instead.
Empirically I know that dielectric material can affect the conductor , and some very detrimentally, particularly those dielectrics which use carbon as the coloring agent. Carbon itself, although used by such luminaries as A.J. Vandenhul, has very high resistance, indicating that it should have a noticeable group delay.
Perhaps he was visualizing the conductor and insulation interface as being a waveguide, factoring some air space, which can carry signal, particularly the highs( the bundled litz construction of the Cardas designs would lend itself to being sensitive to this artifact).
The interviewer, though, never asks the obvious questions.
The inductors he mentions for the phone lines can be seen in MIT and Transparent and Monster products, although I am sure they are adjusted for different frequencies. Brisson once said the boxes on his cable desings were to adjust for the differences in the three wire gauges used in his cable construction.
FWIW and YMMV
Hi and thanks a lot for the very valuable advice.
Above all other things is this idea of a "conductive" dielectric.
To me it sounds like a water fuel ... a non sense i mean.
Dielectrics do not carry any signal, any voltage.
Actually they stop signals. They act like a barrier for electrons.
Maybe i am trivializing ...
Or better, as you say, " he had something else in mind " ?
Thanks again.
Kind regards,
bg
Edits: 04/20/15
Actually some dielectrics have limited signal carrying capability. You can look this up in wikipedia under dielectric. It seems that the dielectrics will react to a charge fairly quickly, and becomes polarized.The degree of polarization and the retention of polarity is what determines the dielectric "memory". The best insulation with the lowest " memory" Is polystyrene, even lower than teflon.
It could be that Cardas has found an insulation where this difference in insulation polarities ( inner vs outer surface) can be utilized as a high frequency waveguide.
The wikipedia article mentions frequencies in the RF range. If there is a lot of subharmonics then it can affect the lower audio frequencies.
Sorry to be so vague, but this is relatively new territory for me.
Edits: 04/20/15
Hi and thanks again.
I was clearly trivializing a very complex issue.
As i said i am trying to catch some principles, but it is difficult.
Of course i love Cardas cables. I have already a 300B and i am waiting for a Hexlink Golden V xlr.
It could be my definitive cable if it will give me the midrange i am looking for. I am obsessed by the midrange.
Thanks again.
Kind regards,
bg
bg,
I haven't heard a large variety of cables, but Cardas has bested a number of brands that I have heard in regard to midrange (IMO).
The only issue I have heard with Cardas is a slight possible exaggeration in the upper bass/low midrange (which decreases as you go up in their line.
I have not auditioned any of their current cable releases.
Happy Listening!
DeeCee
Hi and thanks a lot for confirming me what has been also my impression
I have bought also other cables to compare with the Hexlinks
I want to check if the good midrange is mostly due to the use of litz wires in the cables, as i suspect.
I am curious to compare them
Thanks again.
Kind regards,
bg
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