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Below, Stu has proposed that black wire insulation degrades audio signals by introducing group delay in the transfer function of the wire. He says this is due to the non-infinite resistance of the insulation. He also asks for some objective data on the audibility of phenomena like group delay.Unfortunately I'm too lazy to pull out SPICE and try to model this effect to show the magnitude of the potential problem. But I will make some observations.
I wonder if Stu knows the difference between phase delay and group delay. Phase delay is basically the absolute delay of the signal at any frequency. If you listen to a recording made forty years ago, every frequency in the recording will be delayed by a minimum of forty years. This is a huge delay! Fortunately, all the frequencies are delayed by the same amount of time, so there is no degradation of the signal. If the music sounds different now than it did forty years ago, it's probably because the listener's tastes have changed.
Group delay is the rate of change of phase with respect to frequency. It is a measure of the extent to which different frequencies are delayed differently. Most electronic filters introduce group delay into the signal. Group delay is fine as long as it is constant. It's when group delay changes over frequency that potential audible issues arise.
Extensive research has been done to investigate the audibility of group delay. These usually use all-pass filters, which are filters that have flat amplitude response, but non-flat phase response. Most multi-way loudspeakers are all-pass filters and introduce substantial group delay into the signal across the flat part of their frequency response. For this reason, this question is very interesting to speaker designers.
The research has shown that group delay can reliably be heard when it exceeds a frequency-dependent threshold. There are some caveats, though:
* The experiments were done with very simple test signals designed to maximize the perceived effect. The difference is much more subtle with real musical signals.
* Differences are most easily heard with headphones. Loudspeakers in a room environment are subject to all kinds of interference effects that mask the effect of source group delay.
* The thresholds are quite high.The figure I have found for threshold of audibility of group delay at 1kHz is 2mS. This corresponds to a rate of change of phase of 0.73 degrees per Hz. Extrapolated linearly, this means a 73 degree deviation from linear phase between 1.0kHz and 1.1kHz. This is a HUGE phase shift, and readily detectable with simple instruments.
I think, based on real-world facts and common sense, that if black wire degrades sound due to changes in group delay, this would be very easy to measure. Since Stu hasn't posted the numbers, all I can go on is that the differences must be extremely small (since you need very specialized equipment to detect them). I have to conclude that the effect of insulation conductivity on group delay is unlikely to be a valid explanation for the subjective differences Stu claims to hear. The difference may be real, or it may be imaginary, but the jury is still out as to the cause.
The most reliable way to validate the claim would be to put it to test in a properly controlled double blind listening experiment.
-Henry
Edits: 04/28/12Follow Ups:
Here is an example where the color of the insulator made a difference, which was measureable objectively with standard test equipment.
Another anecdote from my MRI days, operating at roughly 10 MHz.
An experimental coil for head imaging had three turns of #8 AWG enameled coppper wire in a strange elliptical pattern around a thin-wall polyethylene cylinder roughly 12 inches in diameter. The pattern was defined by drilling holes (through a template plotted on a pen plotter) in the cylinder. Ty-wraps through these holes held the solid wires down, spaced roughly by the wire diameter. Since nylon is mediocre, I used polypropylene ty-wraps. They came in green and black. The black ones arrived first, and the loss of the coil was horrible. Substituting the green ones achieved the expected value (measuring the Q of the coil circuit when resonated at 10 MHz). The black ones were designed to resist UV radiation outdoors, and presumably contained carbon black. The green ones were listed as "natural" polypropylene. You could not measure any DC conductance across the black ones, but they obviously had high dielectric loss due to the E-field BETWEEN wires passing through the plastic. Presumably, one would see a similar effect if the black plastic were insulating two parallel wires in a zip-cord geometry.
This effect is only measurable at RF frequencies, where the capacitance through the plastic is important, and depends on the voltage between wires, not the current through wires.
...While I have no reason to doubt your findings regarding ty-wrap color and RF lossiness, I'd be cautious about attributing the differences noted solely to carbon black content. In the polymer world, UV resistance is usually imparted by a system of specific UV absorbing organic compounds AND pigments. I have no idea what the composition of those black ty-wraps was but I wouldn't be surprised if there was considerably more than simple carbon black in there.I also wonder if there are insulation colors other than black that might be every bit as "bad" as carbon black. Many stable pigments are based on metallic compounds.
Overall, the issue of insulation color in an audio context seems to be loaded with a lot of partial knowledge combined with the power of suggestion...IMO, of course.
Edits: 05/02/12
shit....now I have to replace all of my zip ties with white too? when does it end?
Rage,
Did Dennis or Jeff have anything to say about the pigment in zip ties affecting the audio signal?
That was not something I would have been looking out for.
I wonder if pigment-free zip ties are available anyplace?
We can always find subtle ways to improve our modern tube circuits, it never seems to end.
BTW, I heard about your 2A3 Medwin amp silencing critics at an audiofest.
Nice job.
dt 667
I was joking. :)
Aside from Dennis, who else works with modern tube circuits? I would be interested in learning about modern tube circuits versus old fashioned tube circuits. Do you know if Graaf or Unison Research use modern or old fashioned tube circuits?
Thanks
GEO,You need to contact Jeff Medwin aka DrLowMu and tell him what you want to do. He can get you started in the correct direction.
Other guys to contact would be Rage, Drummerwill, Coronadope, JLH or John Swenson.
There have been others who have expressed interest in building something but have not posted any reports.
I don't know about Graaf or Unison Research.
Never have seen their schematics.
dt 667
Edits: 05/03/12
Is there anyone in the commercial field using modern tube designs or is this only for DIY guys?
Dennis Fraker of Serious Stereo and Jeff Medwin of AMA are the only 2 commercial builders/designers of tube amplifiers or components that are using the "modern" circuits.
There are a number of options for DIY builders to source components that can be adapted to modern tube circuits: Hammond, Triad, Edcore and AMA (Jeff Medwin's company).
You got to know what you want and look around for it.
Your best bet is to ask Drlowmu aka Jeff Medwin for some help getting started.
That is amazing. There are only two commercial guys in the world that understand modern tube circuitry. I will take at look but $12K for 2A3 monos seems a little high but if they sound good the price doesn't matter. We early adopters always end up paying more....I guess Dennis can recoup all the R&D he put into his product.....thanks for the heads up.
Negativity in the form of words and attitudes will NEVER trump performance. Performance-wise in a variety of audio systems, I easily find there simply is "no contest" with Dennis' 2A3 amps.It is usually poor build practice to use tie wraps, it is preferable, and better sounding, to float wires above chassis, separated from each other and their individual fields, crossing each other at right angles, as has been previously discussed here.
Larry D. Moore Esq. uses a "modern supply" in his 845 Monoco amplifier offering, see attached.
Jeff Medwin
Edits: 05/05/12 05/05/12
Jeff Medwin aka DrLowMu has produced a transformer and filter choke set for his modern SE 2A3 amplifier designs.
Rage used the Medwin designed products for his amplifer.
I used Hammond ICT for B+ transformers along with Triad and Edcore filter chokes for a budget SE 6V6 stereo amp.
You don't need to spend a lot of money to get a very good result.
I doubt that I spent over $100 for the transformers and chokes on my breadboard.
The amps Dennis Fraker builds are out of my price range, so I DIY.
Hey, Death. What color Kool-Aid does Dennis drink?
-Henry
"when does it end?"
For me it ends once I hit the power switch. Once the music starts to play I really don't care if my insulation is the wrong color, the fuse is in the wrong direction, or my tubes don't have "windmill" getters; the music sounds grand to me just the way it is.
This represents an excellent example of how these audiophile legends start.BTW, I am not being critical of the post, I believe it is quite factual based on my high power RF expereince in TV and satellite transmission.
However audio store salesmen and magazine journalists come across an issue in high power RF engineering for example and simply extrapolate it to base band audio.
To them who are lacking any formal electrical engineering knowledge, it's just that simple.
Edits: 05/02/12 05/02/12
Insulator Q matters a lot in many RF circuits. But you can easily measure the difference.
Measuring loss in a high-Q resonant circuit is, indeed, very easy. I just loosely coupled the circuit to the tracking generator and input of a suitable spectrum analyzer and measured the center frequency and bandwidth.
By the way, some simple experiments with orienting the "knot" of the ty-wrap showed that the effect was due to voltage between wires, not the current flowing down the wire.
In the case of conductive insulation, you forget that the signal is entering and exiting the insulation at any point of contact. The delay induced is insidious because it can happen at any place and at any time frame. There is absolutely no one rigid time frame that it occurs.
Hence an audio comparison of black insulated wire over pretty much any other color(I haven't tried them all, nor various coloring compounds) pretty much manifests itself as a pervasive smear from top through bottom of the audio bandwidth.
Again, it is a simply ten minute experiment, no instrumentation required other than your ears.
Stu
"a simply ten minute experiment"
You must be a wizz with a soldering iron.
I use black insulated wire as the ground for both signal and power supply throughout both my monoblocks. I bet it would take me a week to change all the wire to a different color. Fortunately, my amplifiers don't exhibit a pervasive smear from top to bottom of the audio bandwidth; I think it is because the signal is not entering and exiting the insidious black insulation at one rigid time frame.
one black strand, say, in one input ground. It should be audible even if you change only one channel as there will be a channel imbalance. If you change the two grounds, then you can have an instant A-B by simply changing the selector switch and moving the IC's. That shouldn't take more than a few minutes. In fact, you can simply lift one end of the ground wire and parallel another non carbon based strand for a quicker evaluation.That's what I did although I experimented with various cables, with various insulations and gauges. The ground wires are just as important as the signal carrying wires, IMHE.
Until you try it, you will not be aware of the smear the carbon adds. I lived with it for many decades, and the simple changing of the wire significantly increased the overall resolution of my system. I started with the inputs of my preamp to the PCB ground and from there slowly changed all the black wires. Fine detail and resolution increased significantly considering how little non back wire can cost, although the time invested is quite significant.
Some may say its psychosomatic, but I have changed out wires for customers' components without telling them exactly what I did, offering a money back guarantee if they were not satisfied (and a return to stock), and never got a complaint in 15 years of doing this.
Of course, if you have voiced your components to accomodate this smear, the change may jar your listening tastes at first: some may find it a bit more analytical, and, simply put, a lot more issues may be audible. I liken the effect like switching from an Instamatic camera to a good 35 mm camera (yeah, I'm an old man). With the Instamatic you never have to focus because it is never in real focus anyway. With the better camera, you will notice the difference with f-stops and lighting and every other controllable parameters.
Again YMMV.
Also remember the semi conductive insulation lying upon the superior conductor means that the signal can go in any direction, forward, backward, sidewards, etc. Not only do you get varying resistances with their corresponding group delays, but you also get varying capacitances and inductances, small though they may be. I believe they all add up to corrupting the sound and the longer the conductive insulation, obviously, the worse the effect.
In response to other posters, I see no need for me to provide further proof. I have literally spent the past two decades examining this issue. I have gone to unusual lengths to obtain wire as uniformly constructed as possible and then comparing the sonics. Being a home hobbyist, I can not afford the instrumentation needed to verify what I can hear is happening. I have O'scopes, ohm meters, gaussmeters, a Genrad SPL meter, which is probably more than most hobbyists. Still, for me measuring the effect is almost impossible. I can, however, distinctly hear the difference.
The hypothesis is very simple: carbon being conductive adds problems to the conductive element. Now considering that there are only three parameters which can affect wire: resistance, capacitance, and inductance; again, consider how a conductive sheath can affect such parameters and what effect it will have.
If you do not believe, that is fine. That's your system and your sound. IF you are happy with what you have, so be it.Stu
PS: ever wonder why an air or vacuum dielectric sounds "better"? Or at least why some claim it does? Ever wonder why some love cloth insulated wire, say like Yamamura/ with their silk insulated wire?
Edits: 05/02/12
Stu, I'm afraid once again I have to disagree.
For fifteen years you've been charging customers to make an unspecified change to their equipment, with a guarantee that if they're not satisfied you'll give them their money back. Don't you realize that just by setting this expectation you have primed them to perceive a difference? This is such an incredibly biased experiment that it simply cannot be accepted as credible proof of anything .
You have proposed a physical mechanism to explain the differences you hear, but, honestly, it's just pseudo-technical nonsense. As DIYers, we should strive for a higher factual standard of thinking and discussion.
I have read many articles explaining how psychology shows that the more you refute a person's beliefs with facts and reason, the more strongly they are likely to hold onto those beliefs. I fear this is one such case, sad as it may be.
If you are interested in pursuing this issue, you should think about what experimental controls you can implement to rule out the possibility of subjective bias. I would have to guess, though, that you're not interested.
-Henry
The bible says it. I believe it. That settles it.
that you are the BIBLE?I have quoted others as hearing original effect. I merely pursued it a bit longer after learning of it from them. I have clearly stated what cables I have used, and where I sourced them from ( Belden and Daletech). Daletech, interestingly, manufacturers what they call a LOW LEAKAGE power cable, specifically engineered for medical use. They have since been swallowed up by a larger conglomerate and is no longer as accommodating of smaller orders.
I have postulated a cause, I have stated what I hear. To further illustrate, I have unbraided Kimber's Silver Streak and replaced the two black copper leads with clear TCSS strands, rebraiding the IC as it was. The difference in comparison to a stock model is not small. I once sponsored an audio club and everyone in the club could easily hear the difference, BTW.
I have experimented with a large variety of cables ( BELDEN as well as Daletech, as well as smaller wire companies willing to accommodate my requests), attempting to insure that the manufacture of the various wires were to the identical manufacturing standards in order to make a more meaningful comparison.
I see no more reason to have to prove to you anything. You can accept the basis of my premise, or call me deaf (and Stan Warren, too, as a matter of fact).
Yes, I am not interested in proving anything to you. I hove done extensive experimentation to come to the conclusion I have. As I have said, you can easily check what I have written by changing one input wire on your preamp. Why should I buy the necessary instrumentation to sooth your ego?I have absolutely no economic interest in making my statement. I simply posted it to help others in their search for better sound. I even give credit to others for noticing the effect. I got no monetary compensation from any of the companies I shared this information with. Since I am not asking any compensation from you, I owe you nothing.
Stu
Edits: 05/02/12
The quote about the bible is from a bumper sticker I saw a few years ago. To me, it epitomizes the sad attitude of people who prefer to take their beliefs from authority figures instead of suffering the inconvenience of thinking for themselves.
Do I think you're deaf? Definitely not. Do I think your perceptions can be fooled, or influenced by expectations? Absolutely. If you think your hearing is an objective measure of the sound that hits your ears, you're already lost the argument. It's a total non-starter.
You insist on ignoring the key distinction in my argument. I believe you 100% that you honestly hear these differences. More anecdotes won't change that. I'm just interested in something else, which is whether or not there is an actual, physical mechanism at work (in the wire) that accounts for what you hear. This is a totally different question.
You've proposed a mechanism and presented it as fact. Speaking as an engineer, I'm telling you your proposal sounds like bollocks to me. You don't seem like an engineer to me -- why bother dressing up your listening experiences with this technical conjecture? The failed attempt to attribute the subjective experience to an objective cause just diminishes your credibility.
By the way, the reason hospital grade power cords are designed for low leakage is that small leakage currents can mess up measurements or even kill a patient. The spec doesn't mean the cords leak less than standard parts, but it does guarantee that they will meet the safety standards. It's just the same as with mil-spec tubes. They're not necessarily better performers than commercial parts, but they are guaranteed to perform.
By the way, the reason hospital grade power plugs are clear is so that you can visually inspect to make sure the ground wire is intact. Some audiophile outfits sell hospital grade outlets and cords as through they will improve sound. It's really pretty useless unless you plan to electrically attach the interconnects to your body and you want to make absolutely sure you won't be killed by a ground fault.
This ultimatum you have offered me -- to accept your premise or call you deaf -- is a total straw man. There is some truth out there on this question. We don't know what it is yet. Whether the effect is real or imagined, the truth is probably more subtle than your black and white ultimatum implies.
-Henry
Mr Engineer, have you checked out the construction of the Daletech power cords? Quite different from the vast majority of power cords on the market, including audiophile ones. I wonder why they went through extra trouble of adding extra insulation when a standard hospital grade cord could work fine.
StuPS: I've stated the reasons why I started this investigation. I have confirmed what I was TOLD by others. I've have advanced a postulate as to why it could have causality in the real world.
Now you write claim that it is impossible. So now please prove to me that it is impossible.
Edits: 05/02/12
I have absolutely no idea how or why Dale Technology power cords are built the way they are. I have to assume because this makes them safer and more reliable. If you're interested, why don't you write to them and ask, then post the answer?
I don't see how this is relevant to your feelings about the sound properties of black-insulated wire.
You seem terribly affronted, but you have to understand I'm really quite dispassionate about this. Black insulated wire may sound worse than white insulated wire. If so, that's interesting. Black insulated wire may sound the same as white insulated wire. That's fine, too. If the former case, I suppose I'd be curious to know the reason why. There has to be a reason, you know.
If I can try to summarize, you have postulated that the signal traveling through the black-insulated wire enters and exits the insulation layer at many random points along the length of the wire. The signal traveling through the resistive insulation material is delayed relative to the signal in the conductor, and this results in a "smearing" of the signal across the audible frequency band. The smearing effect is barely detectable except with the most exotic equipment, but is readily apparent to the human ear. You have discounted the possibility that expectation has colored perception.
I have here pieces of white and black teflon insulated wire. I also have a Fluke 187 digital multimeter which has a conductance scale with a resolution of 0.01nS. That's one divided by 100,000,000,000 Ohms. I am pressing the probes down hard on the insulation about 1/16" of an inch apart. I see no change in the reading for either color wire, beyond the random fluctuation due to noise in the instrument.
Can you quantify for me how much conductance are you talking about here in properly manufactured black wire?
I am trying to understand what potential differences along the length of the wire would cause electrons to flow into this super low-conductance insulation layer in preference to moving through the copper conductor.
I am trying to understand how this postulated flow of electrons into the insulation layer would influence the electromagnetic field around the wire, which is where the information actually propagates. (The electrons themselves only move at a speed of a fraction of a millimeter per second -- did you know that?)
I am trying to understand how this tiny amount of incidental current hypothesized to be flowing in the insulation could cause a random variation in the propagation delay of the signal through the wire that would be audible in any normal hi-fi application.
I'm trying to understand how you can be immune to subjective bias.
I studied electrical engineering. You (and a few others) seem to think that's a crime. Go figure. I studied Maxwell's equations, electromagnetics, and semiconductor physics. But the bulk of my training was in the realm of circuit analysis. Circuit analysis imposes simplifying constraints to make problems tractable. You can't readily analyze a schematic if you have to solve everything in terms of field behavior. Have you got a lumped circuit model for this effect you propose, or does it require that we go all the way back to the field equations to get a solution?
Do you actually, really know what group delay is? Even after reading my earlier explanation?
Show me your model and crank some numbers through it so I can get a sense of the magnitude of the effect. Give me some equations I can puzzle over so I can figure out what you're really talking about.
OK, now this is the part where you tell me again that you trust your ears and you don't have to prove anything to me because the evidence speaks for itself. Right. Got it.
So you were the one who came out with this engineering explanation, and I took you seriously enough to take time out of my day to think about it. And now, you're angry at me because I have pointed out some flaws and omissions in your analysis. Is it because you wanted to appear smart to people, and I came along and rained on the parade?
Remember, I never said you didn't hear the difference. I didn't even claim the difference was impossible. That's YOUR word. All I said was your explanation made no sense.
Stop being indignant and reading things into my words that I didn't say. You want to be taken seriously or not? Yes? You have been taken seriously.
Deal with it.
-Henry
Henry,
Your erudite arguments are pearls before swine, IMHO. For years now, a cabal of quacks has been trying to subvert this forum in order to push its own agenda and peddle its weird brand of snake oil to the gullible. In the hope of stifling opposition, these charlatans continually attempt to discredit qualified technicians, engineers and scientists. I don't think there is anything to gain by arguing with them (other than to point out the fallacies the preach, for the sake of maintaining a balance of fact vs fiction).
get on the suggestions of Tim Fox, and Dave Slagle...ok
If there is a dynamic effect relative to different dielectric constants, this is the next one I would check...how will you check it???
and as for as I am concerned those who need explanations need to do the proving...i.e. very capable people have already done the experiments by listening...Henry: the Church (i.e.you and Gusser) needs to prove to Galileo why the Earth is the center of the Heavens....
and you need to prove why the Earth is Flat...ok....the rest i.e. the users, understand already that the Earth is Round, and that the Sun is the center of the Solar System....like that....then you are in service.
ok have fun,
Sincerely,
-3db
Thanks for the notes. Again, a lot of misunderstanding here.1) Galileo was a scientist. His conflict with the church pitted him against the religious and political establishment who had a powerful incentive to stop the spread of science and reason. Same thing today, when much of the hi-fi industry depends on keeping people from thinking clearly about the value of what they're buying. In this analogy, I am Galileo and the hi-fi tweakers represent the church. The flat-earthers were the ones saying, "Don't think! Trust your senses: the ground is flat and the sun circles the earth!"
2) I keep saying (and I'll say it again) that I'm not declaring the claimed effects are "impossible." Anyone who thinks I said that isn't reading what I've written. What I have said is that the burden is on the people making claims to provide the proof. The burden is not on the audience to prove the claimants wrong.
3) Science is by nature an adversarial process. Scientists propose hypotheses and publish experimental results to justify them. The scientific community's job is to try to shoot holes in the research. It's a process of trial by fire. Good experiments get duplicated and validated. Bad ideas get trashed, or evolve and are reborn to start the process again. The fact that many scientists are skeptical of new theories that are eventually proven out does not mean the scientists were fools, or that the process of science doesn't work. The same is true when accepted scientific theories are forced to change in the face of new research. This is all part of the process.
4) There is way too much valid scientific data showing how fallible human hearing is for me ever to accept at face value that just because one or a bunch of audiophiles "heard" something that this means the "something" they heard was real and not an artifact created in their heads. Do some studying on the topic of psychoacoustics and blind testing methodologies and you'll see what I mean. There is a hell of a lot of neural processing going on in the auditory part of your brain, and it's just naive to think that conscious and subconscious biases don't affect perception.
5) I'm not criticising Stu for saying that black insulated wire sounds different. I'm questioning the engineering explanation he's given us to try to substantiate his claim. His technical reasoning is insufficient to prove the case.
All this makes me think of arguments about evolution I've read on news sites and discussion boards. The creationists like to say that science is just an atheist religion as though this proves the whole issue is purely a question of philosophical relativism. And therefore, belief in science is just another kind of "faith" that is no more valid than religious faith. This is all bunk. There are fundamental, deep philosophical differences between science and religion. If this isn't clear to you, you also need to spend some time reading about the philosophy of science.
Finally, the idea that asking for explanations of surprising claims is somehow wrong is just totally backwards, IMHO. If what you are saying is that all perceptions are valid, and that any lay technical speculation based on subjective observation must be accepted as true by default, then I have a big, fat spaghetti monster to sell you...
(If you don't know what the Flying Spaghetti Monster is, then you can add that to your research list.)
-Henry
Edits: 05/03/12
1) please look again at why I said it the way I did Henry...the history is what I am referring to, and your statements here are typical of the Church...it is true because I said it was , etc....
The Flatland analogy applies because you can show a Flatlander a high mountain, and all perspective lines curved (i.e. an actual experience), and demonstrate a FlatLand having noncurving perspective lines, and he is still going to deliver some positional nonsense....i.e. Dahlquist/imaging, non believing engineers and CD/Nyquist nonsense...I am intentionally eroding that stance of any authority Henry...It has been blown already ...ok
You have to recover here by having some fresh willingness in tone...this is the middle ground, which I don't hear so much...ok
2)Yes the Church hates it of course when I say No...I mean NO Henry because of the nonsense...the Audience that has some problem, even with their Tweekers assigning causes inaccurately, is now burden with showing the proof.
You need to grasp this: this is what Galileo incorrectly died for...why should he have to prove the truth to the Church Henry??? This is a problem...as far as I am concerned listening is now way closer, and the denial problem on the engineering side so great that the situation needs to be reversed...if fact authority incorrectly assumed is the problem here....
3) Thank you Henry, I agree here, and am actually just doing my job.
4) and I agree...and I have done the work here...examining one's own perceptions is the primary work...measurements help,but actual insight into the colorations of one's own senses is the most important...and Henry how do you do this...by actual listening and examing one's listening directly, seeing, and actually examing one's seeing (I am a photographer also, the same colorations come into play, just different),
touch, smell, etc...actually I have done a lot of research. I also have no problem with double blind listening ...it tells a lot, particularily with "educated, able to make distinction, listeners"
5) and again, I have no problem I wasn't criticizing: I agree directly, and was saying arrogantly yes (no further use), and move on: because what Dave Slagle, and Tim Fox have to say might get closer to what the distinction is, and real measurements might offer... and Stu is fine and correct about what he is hearing...I actually appreciate his comments..
ok...I am busy and on vacation...so please you and Gusser rip me a new one while I am gone...
thanks
-3db
listening is not the only way of course, but I am honestly interested in getting to some sort of middle....It is not hard...
I had to listen all kinds of nonsense from lots of engineers during the beginning of Dahlquists work....and how many would just go listen and then, ...begin to evaluate , question, challenge...etc? few...
(Tell me Henry: how do you quantify "Imaging"...is Group Delay sufficient?)
Then we had it again during the introduction of the CD..." i.e. no , the CD sounds like crap, sorry Nyquist frequency is all you have to do, trash, and who was listening???" etc...how long did we go around that...
(How do you quantify "Digital Nastiness?")
As far as I am concerned if you don't listen, and are not quite capable of making a lot of fine distinctions concerning what you hear, and also an engineer not capable of parsing problems...then in general one is not competent and should be in a different business....I don't mean you directly because I know you do listen...thank you...however the notion that something is Quote "wrong" because it doesn't fit your theory, or someone's published work....just needs to be thrown out on it's head, as surely as the Church needs to thrown out with respect to Galileo or concerning Flatlanders...etc...
i.e. order of relavence:
First Listening
Second Measurements
Third Theories and Explanations...
Have you read Godel yet Henry???
Sincerely,
-3db
What you propose is the typical untrained hobbiest approach.1) Slap some parts together from somebody else's schematic.
2) Listen to it.
3) Hey it sounds great because I built it.
4) Measurements - why? It sounds great!
5) Theory - Why again? It sounds great!I'm sorry but that's not the way audio (or any technology) products are designed and built in the professional world.
1) Model the circuits. Either by calculator, slide rule, pencil and paper, or computer sim.
2) Bread board the design.
3) Measure paramaters and verify the math is correct. Adjust as needed.
4) Listen to it. If somethings not right, then go back to step 1 & 2.
5) Then, design for production and package it.
6) Measure and Listen again to the finished prototype.
7) Tweak the packaging design as needed.
8) Measure and Listen again.
This idea that match, physics are optional is again just a rookie hobbiest myth. So you can get away with it for a while. But sooner or later you are going to hit the wall and have to learn how thus stuff really works.
Edits: 05/03/12
because no one is going to pay you to reinvent these ancient wheels...
You assume 1 through 5 is accurate, but of course it isn't...
because you need to get to the middle Gusser, because
1 through 8 is actually what happens, except that you needed to come back to me with better than 1 through 5, because I have to call you out Gusser on 4,6,8 as being unfortunately steps you never do, and you are going to have to prove it to me now....so, please step up a bit Gusser...Are you blind enough to see that what I have said here is not in the middle, and how it resembles a lot of what you say???
I am saying this because I think you actually mostly do good work Gusser...I'll be blunt, if I were your Boss, I would say: you could simply start to develop a little more experience/time connecting actual sound to circuit characteristics/material properties, and less time to reaction.
Ok so generally 1 through 8 are true if one is doing a decent job, except that I would add that 4 and 3 are usually reversed, because half the time I am hearing things I don't like before I measure. The things I hear wrong are half about taste...and the other half are that I unfortunately have not so much done bad math, as forgotten some fundamental assumptions, like I can't put the switching were I want, and I should already know that....
So good luck
-3db
Here:And here are the newer tube amps built in 2008.
http://home.earthlink.net/~tubesforht/
Edits: 05/04/12
I am out of my league here but all this debate is very similar to debates about the Hogan amps....people like the way they sound despite the fact that John did so many unconventional things.....but whenever you would question it, the wolves would come out....finding out the whys is always a healthy discussion....it is more to it than it just sounds better....kind of like how 12AU7 clear tops sound open and smoked 6SL7s sound dark.....funny.
1) Kimber is told black wire sounds bad.2) Kimber buys a $100K device and finds black wire has problems. So we are told here, Kimber doesn't publish a word about this though.
3) Some audiophile club test a rebuilt Kimber interconnect with black wire replaced and hears "no small difference"
4) Kimber still sells braided interconnects with black wire.
5) What's wrong with this picture?
Doesn't sound to me like Kimber is on board with this idea either!
And I am hardly a Kimber supporter!
Edits: 05/02/12
the following products from Kimber
Power cable: PK-10 and PK-14
Interconnects KCAG, TCTG, Tonik, Timbre, all Select models
Speaker cables: 4TC, 8TC, 12TC, all select models.
Seems to me only the lower models utilize black insulation....
Seems to me you're just plain stubborn, but that's just an opinion, and I have no instrumentation to test that one out.
8^)
Stu
Not using black wire in favor of a different color costs nothing! Why then would Kimber use it at all after investing so much in test equipment to prove it.Like I said there is nothing I could find published by Kimber relating to the black wire test. Nothing....
I'm beginning to think this whole $100K analyzer is just part of the illusion you are trapped in.
Edits: 05/02/12
explain the effects of previous advertising on current marketing and knowledge but I feel such obvious explanations would be largely wasted on you.
Stu
Nt
Stu, I don't have the time to explain why your conjecture about the mechanism behind the difference you hear doesn't make sense.
I think the most likely explanation for what you hear is subjective bias. But I can't rule out that a valid, observable difference exists. The burden is on you, though, to provide the proof. "Trying it myself" is not proof, because I'm just as vulnerable to imagining things as anyone else.
If I could offer a suggestion, it's to stop thinking intuitively and learn to think analytically. Ask yourself: "On the basis of what factual knowledge do I rest my belief that signals 'entering and exiting the insulation' is responsible for the subjective differences I hear?" If you cannot trace this explanation back to root principles through logically correct engineering inferences, then the only real justification for what you're saying is, "It makes sense to me." Which is no justification at all...
-Henry
If you (freely) download the:
HANDBOOK FOR SOUND ENGINEERS
The New Audio Cyclopedia
Glen Ballou (Editor)
and go to page 29 and 30 of Chapter 2 you will find a lot of real information.
I would also recommend to all inmates to take a look at Chapter 2 too, just for learning the basics of how inner ear works.
Best Regards
Luca
ecc230
If you take a reasonable length of good coaxial cable, properly terminated, it has a constant delay time from DC to very high frequency. The phase shift from the signal at one end to the signal at the other end is therefore zero at DC, and increases linearly with frequency. This constant derivative of phase with respect to frequency is the ideal response for many signals, since it only delays the signal while not affecting the shape, etc. However, 40 years of coax at 1.5 nsec per foot (27 light-years of length) and 0.2 dB per 100 feet (1 MHz) would give a lot of attenuation, even at audio.
Edits: 04/30/12
Coaxial cable does in fact produce small, non-linear phase shifts and reflections that vary with frequency, even when properly terminated. This is due, I believe, to variations in physical tolerances along its length and perhaps also chemical makeup. I have measured these anomalies in the past, and while they are insignificant for most purposes, a sensitive nulling mechanism with a dynamic range exceeding 60dB or so can detect the effect of these disturbances as variations in input impedance.
--------------------------
Buy Chinese. Bury freedom.
I should have said "ideal" coaxial cable. I was just giving a simple explanation about ideal phase response for a finite time delay. One bad problem with practical cables is that the variations in dielectric diameter during the production process may be periodic with respect to distance and give very bad results at high frequencies with interference from regularly-spaced changes in characteristic impedance.
The other month I went through the lumped constant derivation of impedance and velocity factor of transmission lines just to make sure I remembered it.
Fortunately, we don't need coaxial cables to carry our old recordings into the present and the future...
-Henry
It is possible however to build a filter that has no significant group delay. It's called a "transversal filter" or "sin cosine equalizer".I first came across these in the FM head preamplifiers of analog broadcast video recorders. At the broadcast quality level you can't have any group delay in the FM output from the playback chain. You know what group delay can do to FM! However the tape head outputs follow the same 6db/octave curve as any tape recorder and must still be equalized flat from 5mhz to 10mhz in this case. A conventional equalizer has too much group delay. (Although industrial and consumer VTRs used them anyway. But here there was much lower FM bandwidth. Some as little as 1mhz deviation with 4mhz carrier).
The transversal filter has delay lines that add the delayed signal back to the un-delayed signal and thus correct the roll off.
Now in ANALOG audio the delays required to build a filter or equalizer like this were beyond practical. But today with DIGITAL audio, DSPs, and cheap memory transversal filters for audio are quite common.
BTW, why FM in a video recorder?
Well it's IMPOSSIBLE TO RECORD BASE BAND VIDEO ON TAPE! Audio has a spread of 10 octaves where standard 525 line video has a spread of 17 octaves. Even with our analog technology today you can't build an analog equalizer with a 17 octave spread to flatten a 6db per octave magnetic tape response. No way! So the video signal was FM modulated to compress the bandwidth. The playback FM was then demodulated back to base band video. So while you can't record a bandwidth of 10hz to 4mhz on magnetic tape, you can record easily a bandwidth of 5mhz to 10mhz. Same baseband signal bandwidth but now less octave spread. Of course a high head to tape speed of 1000ips is still needed and that's why rotating the heads.I just though a review of some interesting practical technology here would be refreshing among all this magic wire talk.
Edits: 04/29/12 04/29/12
I like the use of capital letters. Is this some kind of sales pitch? :)
No, just high lighting what I think are some interesting points. As this is an audio forum, people here may not be familiar with analog video technologies.And when you start to get into video, RF, and high speed digital systems, you will start to see that a lot of this audiophile theory goes right down the toilet.
Edits: 04/30/12
Why not simply check the dielectric and mechanical properties of the various wire insulations?
If on a simple level we can accept that different caps sound different, can't we simply look at the three major factors that give a cap its "sound"
the "conductor", the dielectric and the physical construction. Since we can assume the conductor to be constant between one makers wire, that leaves the dielectric and construction as the next thing to look at.
A simple dielectric test can be done with a megohm meter and plotting the resistance of a bifilar pair over time at various voltages. Once the dielectric is fully charged, the voltage can be reduced and the discharge characteristics can be plotted.
To get accurate results you would probably need to do the test with 10 identical samples of one color and average the results and then repeat with 10 samples of another color to see if there is a difference in the behaviors.
Next are the physical properties and that might require getting a bit more clever since i don't think a durometer will help unless you can get a solid cube of the insulation material. Maybe stretch a known length of wire to a specific tension and check the frequency of a "string pluck"
In both of these cases the goal isn't to prove anything but to document a difference. If a difference is noted, then one can move forward.
Even if a noted difference is observed in either of these tests, it still doesn't explain anything other than maybe there is a sonic difference. People on both sides of this are just lazy and all to often they "hear" / "don't hear" a difference, and take the first thing they can grab as proof of their position and run with it.
enough ranting and a story.
Once upon a time there was a young lad named clippy who took much abuse for his gratuitous use of scrap plywood, hot glue, clip leads and moving equipment to build his creations. One day the abuse became so great he made the occasional solder connection and replaced the hot glue with drywall screws. Still the jeers continued. Clippy decided he was going to show them and built a preamp in an aluminum chassis. In order to mount the big 'lytic caps, he sifted through the stuff on hand and came up with some leftover faucet repair washers to isolate the screw termnial connectors from the chassis. Upon first fireup of this creation the fuse blew. A week of troubleshooting ensued and no solution was found and the project went on the shelf and clippy held his head low in shame.
About a year later, clippy came across a genrad 1644 and proceeded to test all kinds of things for their conductivity. It was a new toy and he found out important things like a rottweiler is more conductive than a strip of formica. He also noticed an interesting property that several materials became more conductive with applied voltage and that is when the bell went off. He thought of the plumbing washers and sprinted to his junk box. Out came a different sized washer from the same pack. His DVM showed no conductivity. The megger however was able to test at much much higher DC voltages and show much higher levels of resistance. As the voltage went up, the resistance dropped drastically and the thought that the insulators becoming conductive at high voltage may have been the issue.
The carcas was brought out of hibernation and the caps isolated by air and the fuse didn't blow. Next came the search for a new insulation material and in the same bin were some washers from a different manufacturer. The megger showed them to be great insulators even at 1000Vdc. A quick swap was made and the project was finally completed and a Loesch 5687 linestage was born. Words cannot explain how how this beautiful creation sounded. I can still hear clippy's words to this day. He uttered a simple concise "this sucks" and went back to his plywood ways.
As a footnote to this story, the insulators that were conductive were black and the nonconductive ones were blue. Also the Blue nonconductive sink washers were the premium "long life" units.
While the above story is true, names have been changed to protect the ignorant.
dave
Everybody is going to have to do a little work correlating audible phenonmenon nnnnnnn (sufficent nnnnnnnnnnn's? ) to measureable quantities.....
And this is not easy....one, these things are hearable??/ questions for the big question mark people who are afraid of snake oil...??? what do they sound like??
Question for testing as Dave gives many hints....Measurement what???
All the people who want the comfort of "so called" objective, already published material, might have to get off their ass and do a little work....instead of nay say: contribute...
and Finally this is really for Henry: What are you in service of??? anyway...some nonsense in your mind?? Like many styled "Academics"...rather like Luddites...same just different...
Anyway...I am in service here, and in my Business...for the Pleasure of the experience of Music....i.e. I am here because I have some Passion about actually having a really Exquisite, Visceral, Moving experience of Music for my clients, and actually "serving people through Pleasure in Music" is a very real thing, which makes money, and puts me on the front edge of what is good in Audio. Yes I care about measurements in order to maintain quality, but that is all...why did Kimber measure something at all??? Because they care about their customers, and need knowledge to serve them! Simple...I don't think they give a damn about what comes down on one side or another of someone's pet theory, nor do they care if it is conventional. and if it were me, frankly it is confidental data which represents an edge on the competition, which is why I and others have not been able, so easily, to find it....
ok enough....I invite that we might have a project for the service of audio??? or just another pit of arguments??? and yes I am not much better..I get cranky with Henry like I used to get cranky with Jeff...
anyway peace, and good Music
-3db
We are talking wire color of mass produced teflon insulated wire that all have the same rated dialectic voltage breakdown in the context of internal amp wiring and the specific impact of audible group delay caused by the color. I measure zero voltage on both the red, white and black insulation on the B+ line for both AC and DC.
It is one thing to keep an open mind, but having no filter whatsoever floods the brain with garbage.
This color of the plastic/rubber insulation of the wire reminds me of the old: "cloth, push-back wiring" has superior tone to modern wiring.The only reasons I use it still, is to maintain the vintage LOOKS and that these wires hold their position a bit better, when bent or tweaked, than the thicker synthetic insulated wire.
TONE? Kinda placebo.
FWIW, I bypass any "ground polarity" switch on older amps. And put in three prong, grounded AC wiring. But, I leave the dead ground switch in the amp. To preserve the original looks.
There have been more tha a few ppl that have said, "this position or that position" of that switch = superior tone or quiter operation than the other. If it does it for them... fine. Absolutely no harm done.
Edits: 04/29/12
"While the above story is true, names have been changed to protect the ignorant."
LOL!
The black rubber washer almost certainly contained carbon black. The blue washer contained some sort of dye. The resistivity/conductivity differences are obvious .
Eli D.
"To get accurate results you would probably need to do the test with 10 identical samples of one color and average the results and then repeat with 10 samples of another color to see if there is a difference in the behaviors."
I did that test with a highly specialized HP transmission line test set about nine years ago. The subjects were various colors of twisted pair in unshielded CAT 5. What we discovered was that over runs of 1/2 mile or longer, differences in propagation time, balance and loss could be consistently attributed to wire color. The worst was always the worst, and vice versa. It should be noted, however, that the differences we saw were truly minute. Taken in an audio context, it's more likely that an audiophile in L.A. could hear a cow belch in India.
--------------------------
Buy Chinese. Bury freedom.
Hi
I do not intend to rain on your parade, however, the four twisted pairs within a CAT 5 cable have (as specified) slightly different # number of turns per meter, in order to avoid crosstalk.
Using sufficiently long runs, different color CAT 5 twisted pairs from the same spool will show different capacitance and inductance measurements, therefore slightly different signal transmission behavior.
Best wishes
That's correct for CAT5E and above. Due to the different twist spacing difference there is also a physical length difference. Not a problem for Ethernet but when CAT5 cable is used for analog video as in a KVM extender, this causes some mis registration of the analog RGB over a long run. ALso when used to extend HDMI, this timing skew causes problems in the digital RGB data as a well. The delay is typically corrected in these applications by variable delay lines in the CAT5 receiver.
OF COURSE THIS LENGTH SKEW IS IRRELEVANT AT AUDIO FREQUENCIES FOR THOUSANDS OF FEET!
what wire color was "worst"? I reckon you are reluctant to reveal it, because it may encourage a certain someone, or two or three, who have certain convictions re black wire. But don't leave us hangin'.
"Taken in an audio context, it's more likely that an audiophile in L.A. could hear a cow belch in India."
The "Emperor's New Clothes Syndrome Virus" runs rampant in our community. All of us are vulnerable and constant vigilance is in order.
Eli D.
There is lot's of masturbation going on in the forum....
It makes it very difficult for someone who aspires to be a good builder to use much of the data that is puked out...
If we could all bring out creations to one location and have a good ole Fashion listening session, we could rule the audio world:> ).
Stuben
"He says this is due to the non-infinite resistance of the (black wire) insulation. "
What is the insulation resistance of bare wire?
Is this in a vacuum?
The original supposition here has the same problem as the HandyAndy posts, miss-appropriating science-y terms to support conjecture.
I have no problem if people say they don't like black wire. We are superstitious as a species.
I want to know how the group delay of a power cord influences its sound.
-Henry
Or case construction. 60/40 solder vs. lead free, IEC and RCAs, romex, switches, line transformers, turbine manufacture, coal/methane/oil.
At least my stereo(s) sounds really good.
I was thinking today if wire quality doesn't matter inside the magnetic field of an inductor, why not make the chassis out of nickel-iron and wrap a few hundred turns of the AC power line around it?
-Henry
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