John Curl's Blowtorch preamplifier part II

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#50,603
jcx said:
I believe I'm the one that brought Ordinary Magnetoresistance, the Corbino Disk (Scott too, independently, I believe) to the table, if the geometry pushes the wire out of coaxial symmetry, solenoid mag field adds components that cause the Lorentz Force to modulate the charge carrier path lengths...
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I am not bringing anything exotic to this table. What I detailed to you was a test design that will discern resistive proximity effect induced changes. If you would rather talk down to me with "rocket science absurdities" than perform an actual test, be my guest. But let me know right now if you have no intention of engaging the discussion or approaching the problem from a scientific or engineering direction. I had assumed you were of a technical mindset and understanding, perhaps I was incorrect.

If you bothered to look in my gallery, you will see that a .2 mH air core 18 gauge inductor climbs to 20 times it's dc Rs at a frequency of about 30 KHz. A 5 mH #15 gauge air core goes totally nuts, running 20 times at about 8 kHz (also in my gallery).

If you do not understand proximity effect, just ask. Condescension is not required nor appreciated.

jcx said:
...then maybe you have something that affects 100 T pulsed magnet design
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The highest field magnet we have is 24 tesla. Normal superconductors are difficult above 20 tesla as the magnetic forces exceed the yield strength of copper, even at 4K. I believe that's at 60,000 psi.

jcx said:
so to see this at audio frequency I need cm thick Cu? or turn up the window unit til I have air condensing on my speaker cable?
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Again, you clearly do not understand proximity effect. Look at the data I put in my gallery. The effect is clearly evident with 20 gauge inductors. So much so, that using a coax braid in the .25 inch dia range provides lots of cylindrical distance such that proximity will modulate the current path in the braid.

jn
 
#50,604
simon7000 said:
Scott, why do you insist on nonsense such as perfect capacitors, you among others have mentioned that internal losses may be modeled as resistor type noise sources. I have shown the vibration induced noise from the V dc/dt component. It is inherent in all capacitors. Turns out it is simple to design out if you know that it is there.
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scott wurcer said:
Where did I say that? You and Frank please download the schematics for an AP it includes the BOM. Find all the precious audiophile approved components.

You do just what you accuse me of, the non-idealities of capacitors have been studied for years and folks have been designing around the problems for just as long, I have never said anything otherwise.
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Perhaps from this...

scott wurcer said:
We don't sneer, just point out flawed and incomplete experiments. With respect to resistor sound still nothing but anecdotal nonsense. Have you ever reported anything more than "I sent some resistors to my buddies and they confirmed my measurements"?

BTW capacitors are a pure reactance and can not contribute noise unless you want to rewrite physics.
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Have you noticed all the new AP research on resistor distortion? Wonder what started that? The AP folks in their original design had custom made capacitors as the existing ones set the performance limit to the input filter.
 
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#50,605
Kindhornman said:
ES,
I am not one to disagree with your measurement techniques or statements of fact or information. What is hard for me to follow with your posts, and you are not the only one who does this is that you start things off as very vague questions that only a few like Scott or JN would really understand at that level, and even they question the accuracy or details of the questions. It would be much clearer and easier if you are trying to help educate us Luddites if you would state your case clearly so we can understand what it is you are saying and how you came to that conclusion. I try to read everything with an open mind, but sometimes asking a technical question that is over my head or others comprehension and then others getting into these battles just makes this thread a cluster "F" if you get my meaning. If we are hear to learn from one another it would help if questions or information was given in a clear fashion and not as a game show question format. Perhaps we aren't really here to learn but for some to just show off their superiority over the masses.
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I try to ask what are very simple and basic questions, it amazes me how some of these are interpreted. If you are interested and it is not clear, just ask. That goes contrary to the practice here, but just might be useful.

The issue is that there are many fundamentals that I assume are common knowledge and seem not to be. The best example was the unit of sabins, how one can claim any knowledge of acoustics and not know the basic unit of measure is surprising.
 
#50,607
KBK said:
the limit (absolute reach) of individual human cognition, in the idea of logic and extrapolation, by default, includes the hard aspects of human psychology and the physiology thereof. Emotions intrude and can even be the dominant factor.
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I want to point out that this is very true. I tend to think that science is not much better than the level of objectivity of the people performing the science, and that even well-performed science by people who are not very objective in their daily lives will often be flawed, and even if it has accurate results, the aim of the entire experiment may be flawed.

For this reason I think it is important to understand cognitive science well. In any case, not being objective as a person will result in making decisions in our lives that always take us somewhere different from where we wanted to go, and tends to result in a lot of unhappiness and tears when our wishful thinking does not pan out.
 
#50,608
keantoken said:
I want to point out that this is very true. I tend to think that science is not much better than the level of objectivity of the people performing the science, and that even well-performed science by people who are not very objective in their daily lives will often be flawed, and even if it has accurate results, the aim of the entire experiment may be flawed.
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I can agree to that as well. A real good scientist spends maybe as much time trying to blow holes in his arguments as he does on constructing the arguments in the first place. Applying the scientific method is necessary but not sufficient.

Jan
 
#50,609
JN, just a little testy?

I need to be doing taxes - so I do resent the time spent looking for your gallery - a diyAduio feature I hadn't seen yet - I'm afraid it wasn't illuminating as to what you expect to be built to test

and just using quick analogies I thought your 20x was unreasonable - speaker cable parallel runs seldom see few dB Rs rise from proximity effect by 20 kHz

I would always start with a single layer coil for testing physical principles - so ~"tightly wound coax, 1mH air core" doesn't scan - I get rather large dimensions for the winding

eddy current loss doesn't appear to be nonlinear in linear, nonmagnetic materials - didn't you see Hofer's account of the Al patch glued to the steel cover over his oscillator when he realized the poor production test oscillator distortion numbers were from the steel cover - which he never used on his bench developing the circuit

and where are sensitive instrumentation transformer designer's, textbook's warnings of added "eddy current harmonic distortion" with electrostatic shield if your account is relevant?
 
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#50,611
jcx said:
JN, just a little testy?
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NO. NOT A LITTLE.😡

It's just GOTTA be happy hour somewhere, no??

jcx said:
I need to be doing taxes - so I do resent the time spent looking for your gallery - a diyAduio feature I hadn't seen yet - I'm afraid it wasn't illuminating as to what you expect to be built to test
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Yah, I apologize for that, I put them in the gallery because I lose track of where in a thread I had put the content. The problem I have now, is I can't figure out how to link any picture from my gallery into a post. It would be great to be able to put up some discussion, then a pic, then more discussion, etc, as that way I'd be better able to illuminate a discussion. Sadly, I don't have any grandchildren available to teach me how to do that on this site..

Once you figure it out, the gallery feature isn't that bad.

jcx said:
and just using quick analogies I thought your 20x was unreasonable - speaker cable parallel runs seldom see few dB Rs rise from proximity effect by 20 kHz
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For a speaker cable, proximity would be really high in frequency, way over 20K. I can't speak on how it would alter timing delays at the microsecond level, but I suspect it doesn't make a difference as our ITD limits with dither never go beyond 12Khz or so, proximity in a zip would be way beyond that.

For an inductor, that 20x is no longer unreasonable. I was quite surprised to see what an 18 and 20 gauge .2 uH inductor did vs frequency.
jcx said:
I would always start with a single layer coil for testing physical principles - so ~"tightly wound coax, 1mH air core" doesn't scan - I get rather large dimensions for the winding
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I be Ed has a 400 foot spool of coax lying around to spare...

Seriously, I'm sure even a .2 to .5 uH air core coax made inductor will show the proximity modulation, it just raises the frequency.

http://www.diyaudio.com/forums/gallery/showphoto.php/photo/9698

edit: well, it's in, but not as a picture...sigh..
jn
 
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#50,613
jcx said:
eddy current loss doesn't appear to be nonlinear in linear, nonmagnetic materials - didn't you see Hofer's account of the Al patch glued to the steel cover over his oscillator when he realized the poor production test oscillator distortion numbers were from the steel cover - which he never used on his bench developing the circuit
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Do not confuse lenz effect exclusion with proximity resistance modulation. The example you cite used a conductive non ferrous plate to exclude dB/dt from the enhancing and non linear effects of a high permeability material with a bad hysteresis characteristic.
jcx said:
and where are sensitive instrumentation transformer designer's, textbook's warnings of added "eddy current harmonic distortion" with electrostatic shield if your account is relevant?
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It is important to consider the angle the flux hits the conductive surface, as well as the level of magnetic field being produced by the coils. Instrumentation transformers are not generally designed such that the flux is supposed to cut through the electrostatic shield.

Both your examples are inconsistent with the discussion.

jn
 
#50,616
Kindhornman said:
Though I have done some weird stuff, many things could be considered somewhat mundane today, but when I did them they were all outside of the norm. I have always had to push technology and materials applications into areas that I have been told haven't been done before. At the same time there has always been scientific method used to get to the end result, you can't just guess about these things, but you do need to use intuition in many instances and evolve those ideas to get to the final point. I would say the same happens in audio, you may have an idea that is outside the norm, but there is always some basis for trying something or an inkling of an idea that you would try. I have a pretty good idea that anything that John has done has come from some technical knowledge that he has learned along the way. That doesn't mean you don't try something nobody else has done but you have some idea of an outcome you are trying to create. Just stabbing around in the dark without any end result in mind doesn't often work. Unless you are working in a place like a Bell Labs where you really don't know what something you are going to try may do, basic research with unlimited discovery potential that is a rare thing. Most people don't do that type of science, only a few get that opportunity and audio isn't an area that you are just willy-nilly putinng electronic parts together with no knowledge of what might happen. We aren't inventing electricity and trying to invent a new way for ears to work, we have a pretty good idea how all this stuff works at this point. Developing new test equipment is rather rare in audio today, doesn't mean someone may not come up with a new tests protocol or stumble upon a new way to measure distortion that nobody thought of before.
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100% agree with all the sentiments here ... 🙂
 
#50,620
john curl said:
Yes Marce, I come to the defense of my colleagues. Look at where you are? You are not on some thread trying to make the cheapest electronics possible, or something similar. Every time you comment, you tend to insult what I do for a living, and often, specifically what I both believe in and have invested money toward.
For example, I have a cable 'break-in' box designed by a colleague that is used by 100's of audiophiles out there. This 'box' was first commissioned by my deceased colleague, Bob Crump, the other` C in CTC, also the true father of the CTC Blowtorch preamp, who made cables independently, on the side, and INSISTED on break-in for ALL wires and audio equipment that we made. Each Blowtorch was broken-in for weeks before it was released, and the silver wire that it was wired with was both directionalized and broken-in for 30 days on the spool, before installation. Can you now understand what I have to 'put-up' with your criticisms?
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First you get all upset that anyone would consider questioning your expertise then you turn around and give an example using a "break in box" and "directionalized" wire. 🙄 Golly and you still don't see the connection?
 
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