There is plenty of blame on both sides. I just happen to have a lower tolerance threshold for groups outside the law.
So your expectation is that everybody must be the content police, and that all who do not knee-jerk-react to such sillyness have no moral fortitude.
First, I have objected in the past to such descriptions on both sides. Obviously you are either unfamiliar with that or I've not done it enough to satisfy you. Since I do not live to satisfy you in this regard, I won't worry about it.
Second, I have defended parties on both sides of the fictional fence you choose to retain. Since you choose to retain this fence, that is your albatross, not mine.
No, it is not a fair request. Since it would never come to pass that everybody exhibited restraint in this regard, your request (as you well know) is doomed to failure, and you would wish to claim a moral victory as a result...(see, I told ya so)...that kinda thing.
I would love it, but I am a realist.
Telling them their wrong is insufficient. Telling then they are wrong a thousand times is still insufficient.
You need to detail scientifically WHY they are wrong, How they are wrong, WHAT they are wrong about, and provide a scientific model which explains in horrid equational and physics detail what is going on, and predictions that will arise from that model that are testable.
The ridiculously foolish phrase " I trust my ears even though I can't prove it", is an abysmal affront to intelligent and educated people. Telling them (audiophiles and scientists alike) they are wrong is foolish.
Detail why they are wrong and how to fix it. That has been my approach all along. Just ask about IC's, PC's, EMC, localization theory..that kinda goop. If any of your so called "scientists (or strawman scientists)" feels the desire to question the fact that IC's and PC's can indeed affect the sound of a system, I'd be more than happy to trash their assertions using derivations of Maxwell's theory, EMC theory, practical application and test, geometric considerations of trapped magnetic flux, amp chassis current control, whatever.. THAT is how you get your message across...detail in THEIR language exactly why they are wrong..reactions consistent with an 8 year old isn't working.
Again, with this "OH YAH, well same to you" schtick. It doesn't work..
Go on??? All I see is you beating your head against a wall. When will you realize it isn't working?
Always good advice.If in doubt I always go with funny...
Ciao T
Look. You and I have much in common, and agree on quite a bit. You are foundering about using a people skills technique that hasn't worked for children for decades. And you misrepresent scientists... your message ain't working. In fact, it is counterproductive.
Please consider changing your techniques.
cheers, j
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I have been thinking a bit about this and I hope it would not be OT to come back to this with some technical questions, from the practical perspective of a guy soldering stuff together. But first: upon rereading I come to the conclusion that I might not understand the calculations as provided. If I multiply the 15nH internal inductance with the permeability figures you mentioned, I constistently get to results 10 times higher than the ones you provide (i.e., with a mu of 100 it would be 1.5uH and not the 150 nH you mention). Anyways, this is not the real question I have, which are just practical.
1) I have an assortment of very nice NGO t.t.h. caps. When I use them, I always take care to minimize path length and area within the path loop to keep the self resonance frequency as high as possible. Now, these rather expensive parts all have magnetic leads, which I just learned increase their inductance. Probably not a good thing, but to what extent is it relevant in real life?
2) some of the interconnect cable I use is the tan coloured Belden PTFE coax, which has very good screening and is pretty tough as long as you don't kink it. However, the inside cable is silver clad copper on steel. Does this imply that the inductance would be let's say a hundred times more than that of the same cable with a non-magnetic core? Is it a component to avoid for audio?
Vac
ad1) you can quite easily measure the elcap inductance.
ad2) no, the inductance of the conductor would not be 100x higher.
A lot of fairy tales here.
Clearly my math skills need woik...your right of course...my error..
Depends on the frequency. I'm betting that the self resonance is well beyound the frequency where the skin depth causes the current to ignore the center of the wires. For rf, probably not relevant..
It most likely will have higher inductance at low frequencies. As to audibility, I cannot say..others here may be able to answer. You could experiment yourself, given it doesn't cost much. Me, I wouldn't worry, but that's just me.
The low frequency inductance of that coax is the sum of the inductance within the center conductor and the inductance between the center wire and the shield. As the frequency goes up, skin effect will cause the wire's current to move to the outer surface of the core wire. As the current skins more and more, the 15nH per foot time mu number will go down, getting close to zero at rf. Leaving only the inductance due to the spacing between the core and the shield.
Belen ignores the core wire internal inductance and gives only the core to shield number because that is what determines the characteristic impedance of the cable at RF. I've found over the years that Belden at least, has been providing fewer and fewer inductance per foot numbers in the wire product catalog, and I suspect it's because users like us would measure the inductance typically at 100 or 120 hz. That will give a higher inductance number that the rf one, so the user would calculate an incorrect cable impedance as a result.
Sorry bout the rant...thanks for correcting my math...I ran out of fingers...
j
ps..Sy, I hilited the answer to your concen in the next post.
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That is quite incorrect, caveat being..the core inductance is a smaller part of the overall inductance, so the full cable inductance does not go up two orders of magnitude.
At low frequency, the internal core wire inductance will be exactly mu times 15 nH per foot.
The actual low frequency impedance is Z = sqr[(L internal + L between)/C]
At high frequency, where cable Z is measured typically, the internal core wire inductance is essentially zero., so the equation becomes:
Z = sqr(L between/C)
If you wish to discuss the equations, speak up, I'll explain the equations more.
But don't expect me to do the math right...I'd have to take my shoes off above ten..
j
Someone has probably confused magnetic induction (B) with inductance (L)
B, of course, depends on permeability.
Please review the math. I have not confused B and H.
The inductance internal to a cylindrical conductor is L = (muzero*murelative)/8 pi.
The inductance between the core wire and shield is L = (muzero/2 pi) times ln (b/a).. Note I've assumed the insulation mu relative is 1.
j
There is. The magnetic field within a cylindrical conductor is a linear function of radius. It is zero at center, maximum at surface, then drops as 1/r outside the conductor until the shield, where it becomes zero due to opposing field of the shield.
I believe we are speaking across each other. The core wire inductance does indeed scale with core mu, but the overall coax inductance doesn't go up like that because of the ln(b/a) term.
j
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John,
Here we strongly disagree.
One of the nice side effects of having test equipment is that when you use both you learn the signature sound of certain things you are measuring.
For example IM sounds different than THD, so when listening to a system and one can identify IM distortion you may wish to play with the output circuit without even looking at a meter.
Then there are things like articulation tests that use listening panels for the accurate results and the electronic measurement systems can only simulate or approach the accuracy of real ears.
Then the real issue is when you are hearing something and the measurements you are using do not show what you are hearing. Playing around has on some occasions shown that what is being measured is the wrong figure of merit.
As an example there are those folks who insist they can tune a sound system using equalizers, audio delays and similar processors to give the best results for "Fidelity" and "Gain before feedback." Now in most demonstrations after they have tuned such a system a skilled operator with reasonable measuring equipment can improve both, which would indicate that the assumption of "Tuning by Ear" is faulty. However in my work neither of those are my tuning goals. I can use instruments to set my adjustments, but then I really do have to listen to be sure that the adjusted system is actually working!
Yes I have had on many occasions tuned by machine and had to start over because the results were quite simply nonsense. Yes for each case I know why the measurement based tuning was in error, and try not to repeat the mistakes. But the final judge is not just my ears but those of the audience.
In my end of the world there are lots of folks who insist the measurements are great and they don't understand why there are so many complaints. (Yes they are measuring the wrong things, but they do get good measurements!)
(Yes I know your modifier was "...even though I can't prove it" but my proof is with my ears! Very circular!)
ES
John, I would not like for someone to get an impression that an inductance of the wire multiplies with wire permeability.
To oversimplify for DIY purposes, an inductance of the COIL multiplies with pearmeability of the coil core, not with permeability of the wire with which the coil is wound.
To tell someone that inductance of the wire is directly proportional to its material permeability would be very confusing.
To oversimplify for DIY purposes, an inductance of the COIL multiplies with pearmeability of the coil core, not with permeability of the wire with which the coil is wound.
To tell someone that inductance of the wire is directly proportional to its material permeability would be very confusing.
We actually are not disagreeing.
However, you bring an EQ into the discussion??? What are you thinking????
My discussion is really only in regard to things like IC swaps, PC's, changes that logically really shouldn't affect the sound. But yet do, and then the audiophile gets the ol' miles and miles schtick, or wires are wires, you know, the typical so called objective or scientific" tirade which "proves" you can't hear the difference.
And then audibility testing which may or may not sufficient to the task of discernment. Especially if changes affect imaging construct, one thing audiphiles so much look for.
j
I understand your concern. However, I prefer they have complete knowledge. I can agree that there will be times when it is too much knowledge.
The internal inductance of a wire does indeed scale with it's relative mu. External is dependent on the current loop geometry.
Since vacufile asked about a specific construction coax, I detailed. But it is also good that you have such concerns about the confusion of others, I think that is worthy.
Your example is one where the external inductance is dominated by the structure reluctance, and entirely different from a coax.
j
ps...I prefer to provide all the information, and help explain if the target is confused.... I do not agree in this case that it is a good thing to withold content based on what I would think would confuse them.
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We actually are not disagreeing.
However, you bring an EQ into the discussion??? What are you thinking????
My discussion is really only in regard to things like IC swaps, PC's, changes that logically really shouldn't affect the sound. But yet do, and then the audiophile gets the ol' miles and miles schtick, or wires are wires, you know, the typical so called objective or scientific" tirade which "proves" you can't hear the difference.
And then audibility testing which may or may not sufficient to the task of discernment. Especially if changes affect imaging construct, one thing audiphiles so much look for.
j
John,
My current bit of audio play is looking at how noise affects circuitry. (Also the effect of envelope modulation on transforms.) It really shouldn't come as much of a surprise that an op-amp such as the LME4562 measures way better than an LF442 as far as harmonic and IM distortion are concerned.
When you introduce a bit of EMI into the same test rigs the LF442 degrades at a much lower rate. At levels of EMI that can occur in normal use the advantage may be to the LF442! (Of course inserting a choke into the LME4562 will fix the problem.)
Now the reason why I started looking is because I reviewed the Burson Modules and although they do not measure as well as many IC op amps they did sound better inside a CD player. So the measurements follow my listening surprises.
Now there are certainly those who have demonstrated that they prefer the sound of some distortions. If they wish to design by ear I have no problem with that. My usual question on that issue is; "Who is the better artist, Rembrandt or Picasso?" Depends on your taste.
There are those who would argue that accurate is better. My response is that you are taking a four dimensional signal partially encoding it in three and then reproducing it, so I have no object to adding false color to simulate or enhance the original emotion.
ES
So, your post clearly indicates that you are attacking anecdotal reports with actual science and measurements..
This shows that you are an outlier to the generic "scientist" thorsten rails about..
Probably why we don't seem to disagree much??
Cheers, j
I would propose you to stop name calling period. It detracts from your posts, it detracts from your character. Saying 'them first' reminds me of kindergarten rather too much.
jan
Hi,
Yes, you are correct.
Ciao T
I find I disagree - a true skeptic would not qualify the word 'evidence' with the word 'good'. That's here a weasel word to dismiss some evidence subjectively deemed 'bad'.
Yes, you are correct.
Ciao T
No.I find I disagree - a true skeptic would not qualify the word 'evidence' with the word 'good'. That's here a weasel word to dismiss some evidence subjectively deemed 'bad'.
A qualifier MUST be used when describing evidence. Simply because it is scientifically and logically unacceptable to embrace BAD evidence. All evidence must be good.
I'm confident we share a better understanding in that: Good and bad qualifiers can be mis-used in order to promote one's agenda, and I am sure that we are in violent agreement that that is appropriate to use good date and reject bad data. The real devil in the details is just how to categorize it such that it is independent of desires.
j
Right on! Especially, when ears are calibraed, tools can be calibtared by them.
I calibrated my ears when designed synthesizers and guitar effects. It was long time ago, but even now when I hear something I can imagin waveform and spectra change.
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