John Curl's Blowtorch preamplifier part III

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Or maybe someone just dowses each cable and pronounces which way it should be connected?

Ridicule is probably not helpful, nor in compliance with forum etiquette. Understood you may be frustrated, as you are only human. But, so is the other side in this matter only human.

Again, people believe their own eyes, and their own ears. Sensory-based perception of reality in conscious awareness is a powerful illusion, no human is completely immune.
 
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A cable which is symmetric or a tiny fraction of a wavelength in length, and contains no exotic materials cannot be directional. There is nothing to sense the direction of a signal, and nothing to do anything with that information even if it had been obtained.
I see a cable as a 2 port network that contains distributed sprinkling of impurities, joints, dielectric absorptions, defects, inclusions, varying metals, varying cystal structure and other esoteric weird and difficult to understand properties that may or may not introduce enough asymmetry to be noticeable. I also have not come across anything scientific stating that the effect of imperfections on commercially available cables to be non measurable. (I can understand matter properties easier than the term "sensing" or "information".) However, differences I noted on non faulty cables are subtle enough not to loose any sleep.
 
Evidence?
Experience, long experience in multiple scenarios, multiple witnesses.

Subtle differences are far more likely to be going on in my head than going on in the direction of the wires. Which allegedly simplified equations do you have in mind?
You need to learn to trust your ears some more.
The equations have two major variants

You repeated this measurements several times to eliminate contact resistance, cable placement, intermittent interference etc. so that cable direction is the only thing which correlates with the difference signal? You have posted the data somewhere for others to look at it?
Yes, I reckon the experiment was reasonably rigorous on all the counts you suggest.
This weekend I will run a repeat with longer record times and more recording events.
If I can get to it I will also knock up an AC power filter/isolation transformer box and see if that usefully alters noise floors.
I'll let you know what I find.
Dan.
 
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Markw4 said:
Ridicule is probably not helpful, nor in compliance with forum etiquette.
My apologies if I have offended any dowsers here with my attempt at humour. My main point was that we have no reason whatsoever to suspect that NASA believes in directional cables or carefully orders only non-directional ones.

I admit to being human. I suspect that most of those who disagree with me are human too.

indra1 said:
I see a cable as a 2 port network that contains distributed sprinkling of impurities, joints, dielectric absorptions, defects, inclusions, varying metals, varying cystal structure and other esoteric weird and difficult to understand properties that may or may not introduce enough asymmetry to be noticeable.
As I said, you need significant length for this type of thing to be noticeable. OK if we were talking VHF or microwaves or long-distance audio; irrelevant for domestic audio.
 
My main point was that we have no reason whatsoever to suspect that NASA believes in directional cables or carefully orders only non-directional ones.

True, but they are not using cheap USB dacs like Dan is either. Not sure NASA or any other similar examples are helping us make progress coming to agreement or solving the perceptual puzzle to the group's satisfaction (or come any closer to it).

In fact, I don't see how any progress can be made the way things are going. Looks like maybe a lot like what has been going on for the last 10 years. Why expect anything different this time unless we do something different?

Dan told me he is fully confident he can differentiate his cables connecting his equipment blind. Maybe he would say he could do it with other equipment too, if he is given an opportunity to listen.

Since none of us are likely to travel to Dan's location to administer a blind test for him, I think he will need to recruit a local psychology professor, or similar who is interested in Dan's work and claims. Think he already found a physicist. We would need to talk to the person to make sure they understand what is needed. Maybe we could set up a phone call between such a person and Jakob2, to talk things over?

Will it work, can it happen? I have no idea, but at least it would be trying something different than repeating the same old arguments over and over for another 10 years.

Maybe it would give us new stuff to argue over (my turn at attempting humor :) )
 
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My apologies if I have offended any dowsers here with my attempt at humour.
Apology accepted, I am a trained medium skilled water dowser. But my skill does not include detection of wire direction. Honest to God truth, no kidding.
My main point was that we have no reason whatsoever to suspect that NASA believes in directional cables or carefully orders only non-directional ones.
NASA has no need for a belief, a non performing cable will fail tests and rejected, consequently the corresponding manufacturer will be flagged. We all know what could happen when parts used on space vehicle was not meticulously specified and tested sufficiently.
As I said, you need significant length for this type of thing to be noticeable. OK if we were talking VHF or microwaves or long-distance audio; irrelevant for domestic audio.
Do you mind helping me find scientific references to arrive at your conclusion, particularly those showing irrelevance for domestic audio? What type of paper or publications to search for?
 
We all know what could happen when parts used on space vehicle was not meticulously specified and tested sufficiently.

Sometimes it still does not help. I was partially responsible for the testing of temperature sensors for the space shuttle "skin". The requirements were staggering. We had to maintain a 0.001 degree ice point reference using water of an exactly specified ratio of heavy water isotopes and the parts were tested and serialized over numerous burn-in cycles. They paid almost $300 (1970's) for a $1 part.
 
indra1 said:
NASA has no need for a belief, a non performing cable will fail tests and rejected, consequently the corresponding manufacturer will be flagged.
Are you implying that cable directionality might be a test they perform, or that after testing a cable they carefully ensure that it is always used the same way round as it was tested?

Do you mind helping me find scientific references to arrive at your conclusion, particularly those showing irrelevance for domestic audio? What type of paper or publications to search for?
It is highly unlikely that any serious research paper or textbook will deal with audio cable directionality, just as no serious planetary science textbook discusses the 'cheese Moon' theory. However, the derivation of circuit theory as the low frequency approximation of electromagnetism will get you part way there. Offhand I don't know which textbooks do this, as in my case it was done in first-year lectures. Then you need to see that a short audio interconnect is basically a trivial potential divider, with little more than series resistance and shunt capacitance. As I keep saying, to get directionality you need length (so distributed phenomena come into play) or exotic materials (which somehow react to the product of electric and magnetic fields) or significant asymmetry in relevant electrical properties.


Max Headroom (quoting Wikipedia) reminds us that Maxwell's equations have two major variants: microscopic and macroscopic. Not sure what point he is trying to make, as the two variants fully agree.
 
DF96, your jokes about NASA, dowsing etc, you think you're pretty funny, what you are not understanding is that it is low level system noises that are altered according to cable direction, and not the high level excitation/information signal, no demons present.

For pretty much any application other than audio this asymmetry of noise behaviours is of little to no consequence.
Rectifying/averaging metering adds positive and negative half cycle information with the result that fine asymmetric information gets ignored.

My testing methodology is intended to reject signal and sense signal driven system excess noise only, and by DAW post processing derive a difference signal between events whose variables are cable direction, system drift and time.
Time raises the noise floor and degrades the SNR of the measurement, any signal correlated difference signal that emerges is due to system drift and/or cable direction difference.


Dan.
 
In reality, it really comes down to the matter of trusting your ears in whether directionality of cables is real. It is generally a subtle effect, but serious audio designers should take it seriously, IF they have a choice in implementation.
We saw the same sort of criticisms, 400 years ago, when Galileo invited people to look at the moons of Jupiter through his telescope. The 'church' at the time said it was impossible for moons to exist on Jupiter, so they could not be there! Sound familiar?
 
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We saw the same sort of criticisms, 400 years ago, when Galileo invited people to look at the moons of Jupiter through his telescope. The 'church' at the time said it was impossible for moons to exist on Jupiter, so they could not be there! Sound familiar?
It does sound familiar. Where we might disagree is in identifying who is Galileo and who is "the church" in this discussion. ;)
 
RF network analyzers will often show a lower SWR using a cable with attached connectors in one direction versus the reverse.

I have read a bit more of electron flow and it seems to agree with DF & others. I cannot find the thesis as it was just before the internet and longer than that for the web.

I do have many other measurements on cables. Some show silver performs better than copper even when the copper is a bit thicker and with less resistance. I attribute this to oxygen defects in copper are poor conductors and in silver good conductors.

Same thing not surprisingly is oxygen free copper works better than old dirty cheap wire.

Interestingly I did try .500 x .02" copper ribbon and it worked very well.

If I get time I will make some changes to lower the noise floor and show the results. I did get some practical suggestions on making improvements. One issue will be to also measure the same conductors with a higher current load. In my earlier experiments using a 10K load much of what I now see did not show up. Which is why I think it is a low current issue. Perhaps that is why professional gear operating at higher voltages and lower impedances does not seem to have the same problems.
 
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We saw the same sort of criticisms, 400 years ago, when Galileo invited people to look at the moons of Jupiter through his telescope. The 'church' at the time said it was impossible for moons to exist on Jupiter, so they could not be there! Sound familiar?
John, I don't think the comparisons are anywhere related in magnitude. Using a church as a fair and impartial judge for these things. History shows that the church back then was against anything that might affect the status quo. They had to maintain power over great masses of people.
It is generally a subtle effect, but serious audio designers should take it seriously, IF they have a choice in implementation.
This is just a commercial point about features to be able to charge more for a cable and position it within a narrow market with massive profits. It's a way to obtain more cash rather than any kind of breakthrough.

Hi Dan,
DF96, your jokes about NASA, dowsing etc, you think you're pretty funny, what you are not understanding is that it is low level system noises that are altered according to cable direction, and not the high level excitation/information signal, no demons present.
Well, actually NASA is working with tiny signals buried in the noise floor often enough. Their requirements for a cable are much more stringent than any audio application is or will be. Sure, they also deal with line level signals or higher, but the signals they recover from distant areas of space are generally extremely low amplitude and on the same magnitude as the background radiation. Those signals are far below that of an MC cartridge.

-Chris
 
In reality, it really comes down to the matter of trusting your ears in whether directionality of cables is real.
Of course it is real but some won't hear it without training.
Dick Heyser nailed it when he said "If two people hear it, it exists".

It is generally a subtle effect, but serious audio designers should take it seriously, IF they have a choice in implementation.
It is relatively subtle, but once heard cannot be 'unheard', and the better the system the more apparent it is.
This leaves the question of what to do about it or even to use it to cancel the inevitable program embedded 'directionality'.

We saw the same sort of criticisms, 400 years ago, when Galileo invited people to look at the moons of Jupiter through his telescope. The 'church' at the time said it was impossible for moons to exist on Jupiter, so they could not be there! Sound familiar?
Yup, and the 'church' will proclaim "It's not a bug, it's a feature !".


Dan.
 
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Galileo brought data. Extremely good data, especially given the era and the instruments available. Not ears only.

There's no excuses for this stuff to be immeasurable and yet audible. And the onus of proof belongs to the claimants. Get cracking, folks, and spend less time on long winded narratives on a internet forums.
 
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(I can understand matter properties easier than the term "sensing" or "information".)

While diving down to the um, nm, pm world, everything becomes a discontinuity.

I also have not come across anything scientific stating that the effect of imperfections on commercially available cables to be non measurable.
The question is, size of imperfections, amount of imperfections and the relevance of all those to the application that that wire is to be used in (engineering)

https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=4297&context=qnde
Defects in axisymmetrically drawn bars caused by longitudinal superficial imperfections in the initial material - ScienceDirect

For pretty much any application other than audio this asymmetry of noise behaviours is of little to no consequence.

I can not even smile reading this.


RF network analyzers will often show a lower SWR using a cable with attached connectors in one direction versus the reverse.


Hi Ed (note: the “directivity” mentioned is the directivity of the bridge, not of the cable)
https://www.keysight.com/upload/cmc_upload/All/E206COMPTEST_METHOD.pdf


George
 
One issue will be to also measure the same conductors with a higher current load. In my earlier experiments using a 10K load much of what I now see did not show up. Which is why I think it is a low current issue. Perhaps that is why professional gear operating at higher voltages and lower impedances does not seem to have the same problems.
Yes. Phono can be very sensitive to cable direction as I discovered a few decades ago.

Dan.
 
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Even with Precision connectors and very high freq..... swr is different depending on the quality of the connectors. One being better than the other end connector. So in changing end for end cable you could get different swr readings... most of that is due to mismatch of source to cable and to load Z. To minimize those mismatches of source to cable to load, we used a 20dB pad at the source end and at load end also. The gen sources usually were not as good a match as a prec load, so sometimes more atten for pad was on the source end.

That is to say the small diffences in each connector could be better or worse Z matching depending on mating complimentary connectors precision.

But for audio ---- if you want to minimize the affects of cable characteristics, one ought to at least start with a very low Zo source over a wide freq range.


THx-RNMarsh
 
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