John Curl's Blowtorch preamplifier part II

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DF96, you have taught me a hard lesson, that I will try to follow. It doesn't really matter what I say here, it is just how I say it.
Of course, I try to be reasonable, and it is quite a challenge, as I have had the same arguments with the same people, SY, SE, and JN for 8 years or more. I am rarely proven wrong, but that doesn't stop everyone from arguing the same points over and over. The same 'cheap shots', etc. It is like a formula.
Where are the other audio designers at my experience level? Where is Walt Jung and Charles Hansen? They are my colleagues, and we talk together often. Why don't they post here, anymore? Do you have any ideas or suggestions?
 
For the higher frequencies in the audio range there is the "skin effect," that is, the flux tends to concentrate on the
outer surface of the laminations, which accounts for the
fall in effective permeability, as shown in Fig. 16.[/i]

se

Then what accounts for a slight rise in permeability at higher inductions (even at 20kHz) in thin Mumetal laminations when the effect of eddy currents would presumably be at its strongest?

John
 
DF96, you have taught me a hard lesson, that I will try to follow. It doesn't really matter what I say here, it is just how I say it.
Of course, I try to be reasonable, and it is quite a challenge, as I have had the same arguments with the same people, SY, SE, and JN for 8 years or more. I am rarely proven wrong, but that doesn't stop everyone from arguing the same points over and over. The same 'cheap shots', etc. It is like a formula.
Where are the other audio designers at my experience level? Where is Walt Jung and Charles Hansen? They are my colleagues, and we talk together often. Why don't they post here, anymore? Do you have any ideas or suggestions?

John, in this case no one is trying to prove you wrong. We are discussing amongst ourselves details of this phenomena and how to measure it.
 
John, some of the cheap shots were fired by you. I seem to remember remarks about professionals vs amateurs, apprentices vs graduates, and international prize winners? It was clear to a relative newcomer (on this forum) like me that there was some 'history' between those in the argument. This meant that many people seem predisposed to be more aggressive than they usually are. Your apparent reluctance to offer a simple physics explanation did not help.

Even now, you are talking about "my experience level". Remarks like that do not win friends. Scientific argument must be settled on the science, not the eminence (real or imagined) of the people involved. There is no room for gurus in science!
 
Freq dependent resistance is the correct way. This is not a fiddle - you can actually measure the resistance. If you put current through it you get I^2R losses. If you assume that the whole transformer is at one temperature you don't even need to worry about the physical origin of each element of measured resistance.
I guess I have to agree with that. Seein's as that's what I said about 3 bazillion posts ago (maybe friday?)

Course, I didn't get the fiddle reference...:confused:

No, but others have implied that JC was imagining things.
Actually, some may have actually said that..especially given John's propensity for shall we say, "creative physics fiction". Over the years he has spouted various physics "explanations" that were without merit, so I believe many will make the assumption of "business as usual".

I try to take each statement or understanding on it's own merit. Despite the fact that John C stated some "crazy" thing, I try to look at it on merit.
I thought so at first, especially when he seemed reluctant or unable to offer a reasonable explanation. At times he resorted to shouting, or sneering, which made me even more suspicious.

That's him...always has been, always will be. The fact that he cannot support a reasonable explanation doesn't mean his observational skills are bad..just that his understanding of physics is pretty rusty. And I do give him credit for attempting to figure out the physics. But he considers a discussion of the physics as an attack against him, especially if he has it all wrong. Again, it is what it is...
It was only when I began to filter out all the noise and confusion, and think about the actual physics, that I realised that he was probably right but he seemed unable or unwilling to offer a coherent explanation.

He didn't have a coherent explanation to give. Only after I started the eddy loss==>effective resistance stuff and we all started discussing, did he start to jump on the bandwagon..

They seemed to continue banging on his door for an explanation even after I had offered one instead.
Hmm.. this is such a long and fast thread.. Did you post eddy loss/series resistance before me?? I'd love to read it if so, can you provide a link? Thanks.

Some here would do well to listen through JC's ears and hear his words of experience.
Standard theory does not quite explain all.
Eric.

You are half right...half wrong.

Some here would indeed do well to listen to JC....

But...
Standard theory absolutely does explain it.

Gee, I was right, after all! '-)
Don't get a big head now duuuude..:D

Of course, I try to be reasonable, and it is quite a challenge, as I have had the same arguments with the same people, SY, SE, and JN for 8 years or more.

For my part, I'm keeping you honest John. When you're right, I tell you. When you're wrong, I tell you.

And in all cases, I detail exactly why you are right and why you are wrong.No more, no less.

In this particular case, I refused to allow your accurate observation to be dismissed out of hand..

Condescention on your part has never been justified.

I am rarely proven wrong,..

Certainly incorrect. But no matter..

Where are the other audio designers at my experience level? Where is Walt Jung and Charles Hansen? They are my colleagues, and we talk together often. Why don't they post here, anymore? Do you have any ideas or suggestions?
Honestly, my thinking is that they don't want to be associated with your posting style or some of your hilarious physics meanderings... But, that's just my opinion.

Cheers, John
 
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iko

Ex-Moderator
Joined 2008
John, some of the cheap shots were fired by you. I seem to remember remarks about professionals vs amateurs, apprentices vs graduates, and international prize winners? It was clear to a relative newcomer (on this forum) like me that there was some 'history' between those in the argument. This meant that many people seem predisposed to be more aggressive than they usually are. Your apparent reluctance to offer a simple physics explanation did not help.

Even now, you are talking about "my experience level". Remarks like that do not win friends. Scientific argument must be settled on the science, not the eminence (real or imagined) of the people involved. There is no room for gurus in science!

+1

Cheap shots on either part makes one look bad no matter the status or level.
 
JN, you have never taught me anything of significance in all of our interactions. Perhaps, it is just me, but I do tend to 'muddle on' to make successful audio products. The very idea of 'keeping me honest' is a slight, that I do not appreciate it, like so many other comments that you made toward me. I have NEVER knowingly lied or gave misinformation on this or any other website in my life experience. It would be a waste of time for me to do it, and it would give 'ammunition' to my distractors. I don't know EVERYTHING, but I know a lot, and I always appreciate any REAL input from engineers and physicists that actually gives more insight to audio design.
 
Sorry I wish had more time yesterday that was a hurried post. I don't think we need the esoteric references. Let me take a step back because I think I have an experiment that anyone can do.


"I have coils on my desk which are made using 700 or so turns of 15 guage solid copper, and some made using equivalent guage litz. Measurement of both from 20 hz to 50 Khz clearly shows the equivalent series resistance of the solid goes nuts, exceeding 300 to 400 ohms at 20Khz.
Am I being told that both will have the exact same noise should I push 20 Khz 1 ampere into them?"


Yes, except for heating and other non-ideal effects

Gosh, I meant that all the noise would be accounted for by the real part of the resistance at 20kHz. This does get confusing. And this can be measured from the terminals with only the self noise as a "signal".
 
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+1

Cheap shots on either part makes one look bad no matter the status or level.

That is why I prefer .22 for target shooting much less costly than larger calibers, but it does make you look silly on the range when everyone else is shooting relatively speaking cannons! :)

That was also an off topic bit for those who are satire impaired.

Can we continue with Scott's experiment?

Scott I find it a bit hard to conduct from the telegraphic post, why don't you flesh it out.

John, I take it you did not get my email or don't agree with it.

ES
 
Did you post eddy loss/series resistance before me?
I don't know. My memory is poor, and I can't claim to have read the whole thread. I don't claim to be the first to mention eddy current as an issue.

However, we have been arguing for a few days about the nature of the eddy current issue. I claim thermal noise arises from this loss mechanicm, and you were disputing this. You were saying that there is a noisy back-reaction against a signal, but that would mean no noise from this mechanism if there is no signal. I'm not sure if we now agree or still differ!
 
That is why I prefer .22 for target shooting much less costly than larger calibers, but it does make you look silly on the range when everyone else is shooting relatively speaking cannons! :)

That was also an off topic bit for those who are satire impaired.

Can we continue with Scott's experiment?

Scott I find it a bit hard to conduct from the telegraphic post, why don't you flesh it out.

John, I take it you did not get my email or don't agree with it.

ES

Ed, I was suggesting the same thing as DF96. The noise in the system is a signal and you will always see the effects of the eddy losses. Measure the Q of a coil and then make a parallel LC circuit with it resonant at the same frequency. Then look at the voltage noise across this circuit. You will see the equivalent resistance (loss) in the noise spectrum. I see I was confused by JN's extraneous information (20kHz at 1A). The 1A is irrelevant the coil will look like 400 Ohms at 20k and have sqrt(1600*KT) nV/rt-Hz of noise at 20kHz.
 
JN, you have never taught me anything of significance in all of our interactions.
I know. But it's not for my lack of trying.

Happened when I tried to explain EMC compatibility issues in your test equipment when you claimed you upscaled that old ST1700 with new electronics but neglected any and all ground loop issues..remember that thread?

Happened when you claimed the diffusion velocity of electrons was the fermi velocity.. You even got some prof in florida (if I recall) to try to "splain" to me how something I never said wasn't correct..

Happened when you were brandishing Hawksford's very bad and quite inaccurate skin theory goop.

But yes, you are correct..I never taught you anything. You're like a horse I've led to water, yet you'll die of thirst...

Perhaps, it is just me, but I do tend to 'muddle on' to make successful audio products.
No, you do not muddle. You experiment, you use your observational skills, your produce excellent product as a result (from what others have told me..remember Phil Tower?).
The very idea of 'keeping me honest' is a slight, that I do not appreciate it, like so many other comments that you made toward me.

No, it's a point of humor. You need to develop a sense of humor..

I have NEVER knowingly lied or gave misinformation on this or any other website in my life experience.
Never said that. Never will. edit: and, I would argue anybody who claimed such inappropriately.

You divert, John..

I don't know EVERYTHING, but I know a lot, and I always appreciate any REAL input from engineers and physicists that actually gives more insight to audio design.
Aw gee, guess that leaves me out, eh??

Gosh, I meant that all the noise would be accounted for by the real part of the resistance at 20kHz. This does get confusing. And this can be measured from the terminals with only the self noise as a "signal".
I was hoping you'd correct that. Now you are in agreement with me...(perhaps now would be a good time for you to rethink your stance??.):p

John, I take it you did not get my email or don't agree with it. ES
John who? Me? (edit...got it, thanks)

I don't know. My memory is poor, and I can't claim to have read the whole thread. I don't claim to be the first to mention eddy current as an issue.

I do claim that. Of course, I've not read the entire thread either, so I'm not gonna look for anything that bursts my bubble...;)

However, we have been arguing for a few days about the nature of the eddy current issue. I claim thermal noise arises from this loss mechanicm, and you were disputing this. You were saying that there is a noisy back-reaction against a signal, but that would mean no noise from this mechanism if there is no signal. I'm not sure if we now agree or still differ!
You know, I'm not sure either. However, I believe we are not arguing. This has been an intelligent discussion. (don't burst that bubble either..please)

But I'm confident that the mechanism can be measured via a two terminal effective resistance test at frequency..and that if there is no signal present, the noise would be consistent only with the coil itself regardless of the core construction assuming consistent inductance. Remember, measurement of the coil noise voltage by itself doesn't push current, so there will be no coupling to the core such that the inductance of the core and/or eddy loss is involved.

I see I was confused by JN's extraneous information (20kHz at 1A). The 1A is irrelevant the coil will look like 400 Ohms at 20k and have sqrt(1600*KT) nV/rt-Hz of noise at 20kHz.
Yah, sorry about that. My tests have been 20 to 20k and 1 ampere to ascertain phase shift and eddy/winding losses, so naturally I just used it..

So I guess we all agree that the noise generated at a specific frequency will be dependent on the Rs component of the Ls-Rs model?

And that by using equipment like the HP 4284A to measure Ls-Rs from on terminal set, we should be able to determine equationally the amount of noise that will result from both proximity and eddy dissipation.

That would be a very good coup....

Cheers, John
 
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Can you cite an example of this so I can take a look at what you're talking about?

se

5530129434_6fd65a1346_b.jpg


I said a slight rise but as you can see, permeability effectively doubles at 20kHz near saturation, which would seem to be related to domain stiction issues.

John
 
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Ed, I was suggesting the same thing as DF96. The noise in the system is a signal and you will always see the effects of the eddy losses. Measure the Q of a coil and then make a parallel LC circuit with it resonant at the same frequency. Then look at the voltage noise across this circuit. You will see the equivalent resistance (loss) in the noise spectrum. I see I was confused by JN's extraneous information (20kHz at 1A). The 1A is irrelevant the coil will look like 400 Ohms at 20k and have sqrt(1600*KT) nV/rt-Hz of noise at 20kHz.

Scott,

The issue I have with adding my noise to the currents swirling around here is my rule is that I cannot discuss anything that involves other folks' secret sauce recipes.

From what you have written I can still read it several ways. One way I can give you useful results, the others and I am still not here.


ES
 
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So I guess we all agree that the noise generated at a specific frequency will be dependent on the Rs component of the Ls-Rs model?

And that by using equipment like the HP 4284A to measure Ls-Rs from on terminal set, we should be able to determine equationally the amount of noise that will result from both proximity and eddy dissipation.

That would be a very good coup....

Tell ya what, if anyone's equipped and willing to do this, I'll provide a CineMag CMMI-10C 1:10 microphone input transformer.

se
 
From Soft Magnetic Materials for Audio Transformer: History, Production and Applications:

For the higher frequencies in the audio range there is the
"skin effect," that is, the flux tends to concentrate on the
outer surface of the laminations, which accounts for the
fall in effective permeability, as shown in Fig. 16.


se

Steve

Just yesterday I had to scream at Scott for posting an old and important paper anyone could understand. And here you are doing the same thing!

About the only issue that it did not make completely clear was why increasing the inductance of the transatlantic cable helped to carry the signal. Most folks would have assumed that the increased inductance would decrease the signal strength.

Are you now going to point them the papers on that issue that explain when there is capacitance and inductance in the right ratio's you have a constant impedance? So raising the inductance will actually result in a more uniform loss without frequency peaking?

Shame, shame, shame...

ES
 
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