dfdye,
Just as a lark, to investigate and debunk what the cable snake folks have to say, would you consider putting an audio signal capacitor, down in the 10's of picofarads, on the ground return of the power cord, out at the socket, of one of your more sensitive instruments? Perhaps leaving it possible to short the thing to itself or left to dangle. Then have a look at the noise floor of the instrument.
Bud
Just as a lark, to investigate and debunk what the cable snake folks have to say, would you consider putting an audio signal capacitor, down in the 10's of picofarads, on the ground return of the power cord, out at the socket, of one of your more sensitive instruments? Perhaps leaving it possible to short the thing to itself or left to dangle. Then have a look at the noise floor of the instrument.
Bud
barrier coatings
yes, unfortunately, usually a bright Watts nickel, used with significant class I and Class II levellers and brighteners, which introduce carbon and sulfur into the nickel in appreciable amounts, and cause levelling and brightening at the micro-asperites dimensions. Typically, the vendor wants as much brite and shiney smooth nickel, so as to minimize the amount of $$$ gold to just enough to look gold plated... unfortunately probably not much more than 1/2 micron or so...this is most likely true on even high priced cables.
Best long term surface conditions we used were rhodium plated pure silver surfaces, but that's expesnive stuff.
What is always left out of the theoretical treatises seems to be any mention of all the variables in ACTUAL plating and fabrication technology. Gold )and other metals/alloys/dielectrics) are listed as having one hardness (wrong), for instance, or yield strength, or dielectric constant, surface micro-roughness is measured only one way, usually to support the theory... mechanical and electrical properties of the metals are cast in stone, usually taken from some other ASTM reference book, or some such. We had to independently confirm and/or develop our own specs, and they rarely matched up with available literature. Heck, I helped develop some of the ASTM methods at Bell Aerospace for surface characterization, among other things; they're meant to be "typical" not absolute. EE's et als sometimes don't seem to grasp this.
'nough said
l8tr
John L.
yes, unfortunately, usually a bright Watts nickel, used with significant class I and Class II levellers and brighteners, which introduce carbon and sulfur into the nickel in appreciable amounts, and cause levelling and brightening at the micro-asperites dimensions. Typically, the vendor wants as much brite and shiney smooth nickel, so as to minimize the amount of $$$ gold to just enough to look gold plated... unfortunately probably not much more than 1/2 micron or so...this is most likely true on even high priced cables.
Best long term surface conditions we used were rhodium plated pure silver surfaces, but that's expesnive stuff.
What is always left out of the theoretical treatises seems to be any mention of all the variables in ACTUAL plating and fabrication technology. Gold )and other metals/alloys/dielectrics) are listed as having one hardness (wrong), for instance, or yield strength, or dielectric constant, surface micro-roughness is measured only one way, usually to support the theory... mechanical and electrical properties of the metals are cast in stone, usually taken from some other ASTM reference book, or some such. We had to independently confirm and/or develop our own specs, and they rarely matched up with available literature. Heck, I helped develop some of the ASTM methods at Bell Aerospace for surface characterization, among other things; they're meant to be "typical" not absolute. EE's et als sometimes don't seem to grasp this.
'nough said
l8tr
John L.
"Just as a lark......."
Bud I would never have thought of that, I hope I'm not left to dangle.
Bud I would never have thought of that, I hope I'm not left to dangle.
John L.
Second the comment on dielectric constants. In work done by my tutor years ago we found mylar with from 3.2 to 5.2 and Kapton from 4.0 to 9.0 in constants. Later the Kapton problem was traced to hygroscopic problems at low ambient temperatures and led to the replacement, under emergency conditions, of a tremendous amount of aerospace cabling, as in commercial airliners....
Bud
Second the comment on dielectric constants. In work done by my tutor years ago we found mylar with from 3.2 to 5.2 and Kapton from 4.0 to 9.0 in constants. Later the Kapton problem was traced to hygroscopic problems at low ambient temperatures and led to the replacement, under emergency conditions, of a tremendous amount of aerospace cabling, as in commercial airliners....
Bud
This is drifting again - nobody denies there are bad cables and connectors out there that may have a clear audible effect.
The problem starts when one states that he can hear a clear difference, while no measurements can reveal any differences.
In my book, "audible ==> measurable", which is logically equivalent with "non measurable ==> non audible". The reciprocal "measurable ==> audible" is generally NOT true. Therefore, the correct sequence is to establish that two cables are different by ABX testing then, if so, measure, identify and quantify the differences.
Measuring "something", even if entirely correct and relevant (and God knows we can go down to femtoseconds and easily count electrons flowing through a conductor) tells jack **** about the audibility.
I can understand why cables manufacturers don't want to go into serious cable testing; it won't improve sales over the current marketing tactics of unsubstantiated (if not fraudulent) claims.
One of the best known plating (and old) schema is still widely used in the semiconductor industry (in particular on the back/drain/collector of our beloved power devices chips): Ti-Ni-Ag. Titanium for adherence, Nickel as an (electro)migration barrier and Silver for conductivity. Beats the porous gold hands down, but it's of course much cheaper to flash gold and get that sexy marketable color.
BTW, I have no problems with rich idiots spending $5000 on a power cable. I have a problem with those making that kind of money by fraudulent advertising.
The problem starts when one states that he can hear a clear difference, while no measurements can reveal any differences.
In my book, "audible ==> measurable", which is logically equivalent with "non measurable ==> non audible". The reciprocal "measurable ==> audible" is generally NOT true. Therefore, the correct sequence is to establish that two cables are different by ABX testing then, if so, measure, identify and quantify the differences.
Measuring "something", even if entirely correct and relevant (and God knows we can go down to femtoseconds and easily count electrons flowing through a conductor) tells jack **** about the audibility.
I can understand why cables manufacturers don't want to go into serious cable testing; it won't improve sales over the current marketing tactics of unsubstantiated (if not fraudulent) claims.
One of the best known plating (and old) schema is still widely used in the semiconductor industry (in particular on the back/drain/collector of our beloved power devices chips): Ti-Ni-Ag. Titanium for adherence, Nickel as an (electro)migration barrier and Silver for conductivity. Beats the porous gold hands down, but it's of course much cheaper to flash gold and get that sexy marketable color.
BTW, I have no problems with rich idiots spending $5000 on a power cable. I have a problem with those making that kind of money by fraudulent advertising.
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Trouser sharks were invented, as a teaching tool, to dissuade young males from dangling in socially delicate situations. They are incredibly effective.
Bud
The discussion here is extremely basic and much more is known about contact surfaces. Especially for audio or any LINEAR connection.
syn08. Yes. Now drifting towards dielectrics.
Apart from slow evolutionary changes, human hearing ability is fixed, not so our ability to measure things, in my book the ears will never catch up.
Apart from slow evolutionary changes, human hearing ability is fixed, not so our ability to measure things, in my book the ears will never catch up.
Cardas do rhodium over silver over eutectic brass. Should be decent if it's done right. Have no idea if it is.
Your humour escapes me at the moment. So back to your earlier post.
".... putting an audio signal capacitor, .... on the ground return of the power cord, out at the socket, ........leaving it possible to short the thing to itself or left to dangle."
If this experiment alters the noise floor of the instrument I'll have to believe there is something going on no matter how much it hurts.😀
Okay, but the high-end audio "industry" being what it is, means that there likely will be bad connectors, indeed incompetent designs, masquerading as "state of the art". Or there could be any number of variations in between - inexpensive stuff that does really well, medium-priced stuff that's only mediocre, and many other possibilities. What I was trying to get at in my questions to John L. was the issue of what makes a competent design, and further, what's an economically feasible way to approach that? How do I know if what I have is a competent design from a materials science perspective? I'm an EE with no materials science background, so I ask that in all sincerity, from a "for dummies" perspective.
To me, it's like power amps with sub-ppm distortion. It may be overkill, but if it can be done within the realm of reasonable design, why not engineer the thing so that one need not worry about distortion at all? I may be all wet, but I'm thinking that there may be some very good, yet inexpensive process out there that beats out other, much more expensive processes in terms of measured performance. It may not matter at all from a controlled test of "how does it sound now", but might make a difference in how it sounds many months from now when I forget to freshen up the contacts.
Dear Sir from Kiwiland, I beg to differ. Our hearing is neither linear nor logic, which makes applying even the best measuring tools a rather wonky affair.😀
Pit
Pit
I would agree, but i would also say that our measurement technology is still primitive and we do yet either know how to measure, what to measure, or have hit the limits of things we can currently measure.
dave
andy_c,
If you believe that my treated drivers are snake oil you are surely mistaken sir.
dave
edit: andy deleted his post after my reply.
If you believe that my treated drivers are snake oil you are surely mistaken sir.
dave
edit: andy deleted his post after my reply.
If human hearing is "neither linear nor logic", it sounds more wonky than the science trying to measure it. 😀
John, I have to call you on this random non sequitur. Science continually re-evaluates assumptions, but at some point we leave well enough alone. No physicists question the wave/particle duality of photons, but it was once a hotly contested theory. No biologists question the structure of DNA, but it was revolutionary enough of an idea to merit a Nobel prize. Your "X-rays don't exist" anecdote is representative of debate when an open question is undergoing continual re-analysis.
Here's the argument from another direction: theoretical physicists have "proven" that infinite multiple universes exist, divergent at every potential deviation in a probability function. Yet no experimental proof for this mathematical "proof" exists. Obviously, this multi-universe proposition is still very much in question despite the "proof," and is quite analogous to your X-ray example.
Ah! The old "Golden Ears" phenomenon.
Again, I readily concede that you have built some pretty nice gear (and I would love to have some of your components if you would care to prove to me how good they are! 😀), but until you can hook your ears up to a strip chart recorder (or ADC card if you prefer to use more modern equipment) then forgive me if I don't accept your personal subjective opinion as scientifically reliable evidence. (Reading back over that, it sounded a bit more snarky than I intended, so please don't take that comment personally--just trying to make a point)
Not sure what he said, but I did indeed just request a copy of your book recommendation via ILL. Even though we may disagree about some stuff, I am never one to reject the experience and lessons of people who have experience to share! Thanks for the reference.
This doesn't exactly agree with my (admittedly limited) experience with the gold nanoparticles and gold surface enhanced Raman spectroscopy (SERS) substrates used in our lab and in our department. Granted, the nanoparticles that my coworkers make are typically surface passivated, but I have not heard or seen any data indicating that gold oxides form at the surface of these particles. Similarly, the SERS substrates that I am familiar with rely on partial bonding of materials to bare metal (assuming you subscribe to the charge transfer explanation of the SERS effect and not the surface plasmon explanation), and the analytes under investigation would not typically bond to gold oxides! This is not to say, John, that your statement is inaccurate, just that it is not consistent with my personal observations. I'll definitely look into it further upon your recommendation. Are you sure, John, that you aren't referring to sulfide surface contamination? That would make a lot more chemical sense!
Also, do you really mean "tunneling?" I don't mean to split hairs, but I'm interested in more deeply understanding how you are claiming the gold oxide impacts conduction between two gold surfaces. If Holm explains this argument, then I will just wait and read his analysis, though I will be interested in seeing how he performed surface characterizations of gold surfaces in 1946. The blurb about this book on Amazon.com did indeed mention tunneling, but I am interested in how he was using the term and whether he was using it in the "quantum" sense. I guess I will find out in a few days.
Anyway, here is my point about all of this tunneling business: I'm not sure if a gold oxide surface monolayer is thick enough to present a classically insulating barrier. Hyperconjugation is readily observed through aliphatic bonds in organic systems, and a gold(III)oxide monolayer could potentially transfer electrons through the oxide ligands, or through some sort of oxide hyperconjugation. Tunneling assumes a classically impermeable barrier through which electrons can be transferred without orbital overlap. Are we really talking about the same thing here, John? Well, somebody HAS to have done those experiments. I guess I just need to do a little library work. No point, really, in further speculation before we know the conductivity of gold oxide and/or gold sulfide or sulfoxide monolayers.
A couple of disclaimers:
1) I assume gold oxide monolayers since I highly doubt penetrative oxidation in a bulk gold sample will occur, though I would readily entertain the possibility if you have some evidence of it. Ball is in your court on this one. I looked and didn't see anything mentioned in the Au surface chemistry articles I found with a quick SciFinder search (didn't look too deeply there--forgive me, it is a Sunday night and I am typing this while watching football!). Plus, it is counterintuitive knowing the reduction potentials of Au(III) (1.52 V vs. SHE) and O2 (-0.13 V).
2) I assume gold(III) since I believe this is the most stable gold oxide--it's been a long time since I read that, so if anybody has a copy of Cotton and Wilkinson lying around, feel free to double check me on that—I couldn’t find it with a quick Google search, so I just went with what I remembered. I readily admit I am not 100% sure about this one! I’m just shooting from the hip trying to remember a transition metals class I took 8 or so years ago.
Regardless of these split hairs, I can say with 100% certainty that all of my good BNC and SMA connectors are gold plated (well, at least the signal pins are in the BNC's). That seems to be a pretty good endorsement of gold plating to me, regardless of the surface chemistry. 🙂
Have you heard of the Holm conference on contacts? This is where the action is. You (and others) should look it up, just to catch up with those of us who have studied audio contacts for the last 30 years. Ask Walt Jung, as he has made a parallel effort, and owns Holm's book, himself.
I don't say that I could not learn a lot from others here, who actually work with metals, but it is important to at least get up to speed as to what we already do to make a good audio contact.
I don't say that I could not learn a lot from others here, who actually work with metals, but it is important to at least get up to speed as to what we already do to make a good audio contact.
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