I assume series resistance did raise a lot. It was an inch from a 200 GEV ion beam for 16 years.No idea, does the damage increase the series resistance (which might have an opposite TC)?
This is from Bell Labs in the 60's when they were still worried about serious radiation damage to semiconductors.
http://www.dtic.mil/dtic/tr/fulltext/u2/650195.pdf
Link stalled for me, probably my IPad. Will check it out when I get to work.
Thanks
John
Sorry if I disturb you, I just did not find that is it obvious that the absence of light embedded in the zero point energy matrix (or Dirac sea if you prefer) propagates at the same speed (of the light). Have not had the opportunity to come across any physics on properties of an "absence of light".No problem with your understanding, it is only terminology. Quoting wikipedia "In physics, chemistry, and electronic engineering, an electron hole (often simply called a hole) is the lack of an electron at a position where one could exist in an atom or atomic lattice." People outside the mentioned field of study can have different definition for a "hole".
Yes, no fundamental reason, only definition. Classical physics I know of define matter as a substance with rest mass and volume that exclude massless particle such as photon. Did physics have a matter definition update I am not aware of?
It has not totally serious, "the absence of light" is a fairly meaningless concept without specifying what is light.
Yes, of course. My point was that until recently the neutrino was thought to be massless, which presumably means that massless matter particles were believed to be possible. As far I know they are still believed to be possible, even though we now know that the neutrino is not one of them. Of course, a massless particle would have to be one which does not couple to the Higgs field.45 said:
Personally, I still don't really know how an audio signal passes through a length of wire. I have, for the last 25 years, tried to find the right textbooks that would give me a satisfying answer, but I have not found it yet.
Theory aside, what is equally important to me is WHY many people and I hear differences between audio cables, yet there is no really good explanation for it.
Now, don't any of you 'experts' out there give me a few tired explanations and then accuse me of ignorance or being a shill for some wire company. I've been around, listened to the opinions of too many people that I trust, as well as my own ears, and have too many physics texts that I have acquired over the last 25 years, in hopes of a good working explanation of what my associates and I have experienced, to little or no avail. Hummel, my first textbook that I found, is about as good as any and better than most. Some textbooks that I own are more complex, but don't really address what the differences are that we find in cable or capacitor construction as well. We still have to depend on the listening opinions of serious listeners for the answers as to what works best.
Theory aside, what is equally important to me is WHY many people and I hear differences between audio cables, yet there is no really good explanation for it.
Now, don't any of you 'experts' out there give me a few tired explanations and then accuse me of ignorance or being a shill for some wire company. I've been around, listened to the opinions of too many people that I trust, as well as my own ears, and have too many physics texts that I have acquired over the last 25 years, in hopes of a good working explanation of what my associates and I have experienced, to little or no avail. Hummel, my first textbook that I found, is about as good as any and better than most. Some textbooks that I own are more complex, but don't really address what the differences are that we find in cable or capacitor construction as well. We still have to depend on the listening opinions of serious listeners for the answers as to what works best.
What I have been trying to get to over the noise from the peanut gallery is that the velocity of propagation in a conductor is not absolutely fixed. There can be small variations around it. So while there appears to be a fixed upper bound of the speed of light in a vacuum, in a conductor the path or medium may vary and thus the speed of propagation may wiggle.
John, I appreciate that you and many others still maintain to hear differences between cables, reasons aside and despite of contrarian opinion. the difference to me were never significant enough but I regret to have never go out of my usual lazy self to find better solution nor measure anything. However, previous discussions in this thread by practitioner in audio industry with advanced measurement tools about the subject have developed my curiosity. Was there no measured difference ever made? Perhaps you or others (thank you Simon7000) have more hints, other observations, suspicions or suggestions for a usable strategy on measurement of cables and other interconnect components.
Define recently. I remember TW doing a correction on a report that the sun was about to go out and said that when they added neutrino mass it balanced out. That was mid 80s. So recent compared to relativity but not very recent?
Max,
Where did I loose you?
In my test measurements a single millimeter of .1 mm diameter cable has 1e22 or so copper atoms, each with 29 electrons. If we increase the diameter to 3 mm that is 900 times the atoms so there can be more variance in the path.
Add in some impurities the charges do not use for transit and the variation grows.
So what I think is happening is that thicker wire will appear to have more noise than thinner ones.
Where did I loose you?
In my test measurements a single millimeter of .1 mm diameter cable has 1e22 or so copper atoms, each with 29 electrons. If we increase the diameter to 3 mm that is 900 times the atoms so there can be more variance in the path.
Add in some impurities the charges do not use for transit and the variation grows.
So what I think is happening is that thicker wire will appear to have more noise than thinner ones.
Ed you still need to settle your disagreement with jn. You talk about mean free path which indicates you are talking about the Fermi velocity. This is not the common usage for velocity of propagation. Someone here facile in statistical mechanics should chime in.
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Easy to measure, the noise performance of wire wound resistors is well documented. Even for enameled copper wire you should have enough around to get enough ohms of say #12 vs #24 to measure the noise with no confounders. We measure the mean of the resistance of course and one can certainly change the variance and not the mean (I should have mentioned that above). I can't see separating the two with a simple experiment.
Also remember wire wound resistors are considered among the best for excess noise.
What does this have to do with directionality?
EDIT - Metallic copper has only one free conduction electron.
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I'm differentiating cable direction right now, so it seems.
I need to improve some things in my measurement rig, but so far I am getting a residual according to the direction of one interconnect.
There are factors like amplifier AC power filter/conditioning/isolation that need to be addressed but else wise the measurement system is floating/battery laptop so there are no opportunities for audio frequency earth loops.
I am feeding 2ch mono to a consumer integrated amp via two 'identical' interconnect cables from a USB sound card.
I am comparing the active speaker outputs of the two signal chain/amplifier channels and as is to be expected I get a residual according to how good the channel matching is.
When I reverse the direction of one channel interconnect I get a change in this residual.
Ears will hear this difference, test equipment will not show it.
I need to run multiple/averaging experiments of all four directional permutations to get data, but for now these preliminary measurements correlate with prior subjective findings.
There may be confounders like minor variation in connector earth contact resistance, but in this experiment any such minor resistances should be of essentially zero consequence (I think).
By this test setup I ought to be able to discriminate other cable types also.
Dan.
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Just seeking clarification, thanks.
More opportunity for scatterings.
Different noise at least.
What changes with freq/current/temp ?.
Dan.
Attached are my measurements of three different cables. As cable diameter increases so does the intermodulation noise. Just for fun the cheap audio wire center conductor was .381 mm and the RG11 was 1.628 mm or 20 x log (1.628/.381) = 12.6 dB
Scott I can't see you behind that pile of peanut shells. I am not talking about mass vs velocity. It is all about path length variance.
Scott I can't see you behind that pile of peanut shells. I am not talking about mass vs velocity. It is all about path length variance.
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What are you calling residual? The difference between the two channel outputs?
If you are running two IC's from one device to another, you have formed a ground loop. Through most of the audio band, the return current is splitting 50/50 between the grounds. How are you controlling that confounder?
Forget music, do a swept sine mono, measure the diff vs frequency. You may see something interesting at the reactance break points.
Jn
If you are running two IC's from one device to another, you have formed a ground loop. Through most of the audio band, the return current is splitting 50/50 between the grounds. How are you controlling that confounder?
Forget music, do a swept sine mono, measure the diff vs frequency. You may see something interesting at the reactance break points.
Jn
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