How about watching inrush after magnetizing the core. Use DC to mag the puppy, then turn on the ac with a zero crosser in series with a big diode.
You'll only see the first 8 milliseconds or so, but you can correlate magnetizing level and direction to the first inrush pulse.
edit: you may need to provide another path around the toroid to keep the zero crosser happy, I would expect it requires some quiescent current to work properly.
jn
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As opposed to you, who has presented what exactly?
You keep saying theory proves...you haven't shown that.
You also have not explained away the 2f dependence example scott provided.
jn
OK I'll stop too, the currents involved don't make testing this easy. In parting my electrostatic example requires no non-linearity at all, you can assume pure piston motion of the two plates with no suspension non-linearity and you still get pure second harmonic.
You probably were not around for the sound propagation in water thread. It ended on a happy note.
shhh..math is not allowed..
Strictly mindless back and forth..that's the call of the day.
jn
Maybe, maybe not.
Wind a toroid with a coax, multiple winding layers..drive only the shield with current.
The core voltage will be the exact same voltage as the shield voltage, minus the IR drop..so connect the core at one end of the coax, and look at the differential between core and shield at the other.
Any magnetic non linearity will show up on both shield and core, and they will cancel, leaving just the shield IR drop.
jn
Calculate the inductance referred to the primary. Then the no load current the core will pull. Know the number of turns.
Wind a secondary with sufficient amp turns such that you can drive peak flux into the core using a dc supply..
Use the DC coil to preset any arbitrary remnant field you wish to test. Magnetize it, then bang it with a controlled-on half sine.
Magnetize the core peak remnance in both directions w/rt the half sine charging impulse.
This is the testing regimen that will provide what we discuss.
As to the math...the proximity effect gets more interesting when you start introducing a lag in the magnetic field. Especially at a gapped core near the gap, the fields just go crazy there.
jn
On another subject of discussion, I find that I have a significant departure in concept and methodology from many 'critics' here, and this has gone on for a dozen years or more.
Yesterday, while sorting some papers, I found some print-out by me from 15 years ago on the internet, but another website. It was 1998 when I typed this commentary. I hope that I can show it here. If I can, then I would say that it is MY way of developing audio, beyond college training, 45 years of experience (only 30 when I wrote this) and what I still find 'works for me'.
Yesterday, while sorting some papers, I found some print-out by me from 15 years ago on the internet, but another website. It was 1998 when I typed this commentary. I hope that I can show it here. If I can, then I would say that it is MY way of developing audio, beyond college training, 45 years of experience (only 30 when I wrote this) and what I still find 'works for me'.
Attachments
At the time of my 1998 comments, I was losing ground in audio. My designs were NOT getting good to excellent reviews, even though they used my topology, measured very well, had lots of features, and were cost competitive with just about anything else.
How can this be? It had MY name associated with the newer products, with all the product 'puffing' that marketing could conjure up, why did the reviewers find my latest designs (at the time) just OK, and nothing special? I will give you MY reason, why later or more independent designs actually were met with great success with reviewers and serious audio listeners, in general.
ATTENTION TO DETAIL, including parts,(both brand and construction), layout, and wiring.
Could any significant difference be measured? NO!
It had to be what we found WORKED better than something similar, and we used our ears to make the final evaluation, rather than just measurements, which were always pretty darn good. Take it or leave it, that has been my experience, and if I had not followed this path, I would not be in the audio business, today.
Heck, Parasound was ready to 'cut me loose' after a few 'failed' designs at that time. However, when we (CTC) showed, independently, that we could either completely develop, or modify Parasound products that were really subjectively successful, Parasound finally decided to give us a bit more freedom to design the JC series of Parasound products, and it has worked pretty well. To my knowledge, LESS advertising has been done by Parasound in later years, especially in magazines, YET we always get a good review, with the later designs that I have some design control over. That is my experience, and what I have tried to convey on this thread, is what we found important in audio design, above and beyond the schematic. Unfortunately, I am not able to do any better in this regard, at least on this website.
How can this be? It had MY name associated with the newer products, with all the product 'puffing' that marketing could conjure up, why did the reviewers find my latest designs (at the time) just OK, and nothing special? I will give you MY reason, why later or more independent designs actually were met with great success with reviewers and serious audio listeners, in general.
ATTENTION TO DETAIL, including parts,(both brand and construction), layout, and wiring.
Could any significant difference be measured? NO!
It had to be what we found WORKED better than something similar, and we used our ears to make the final evaluation, rather than just measurements, which were always pretty darn good. Take it or leave it, that has been my experience, and if I had not followed this path, I would not be in the audio business, today.
Heck, Parasound was ready to 'cut me loose' after a few 'failed' designs at that time. However, when we (CTC) showed, independently, that we could either completely develop, or modify Parasound products that were really subjectively successful, Parasound finally decided to give us a bit more freedom to design the JC series of Parasound products, and it has worked pretty well. To my knowledge, LESS advertising has been done by Parasound in later years, especially in magazines, YET we always get a good review, with the later designs that I have some design control over. That is my experience, and what I have tried to convey on this thread, is what we found important in audio design, above and beyond the schematic. Unfortunately, I am not able to do any better in this regard, at least on this website.
Ah, great. I wasn't sure the e-mail made it.
I tried to keep the writing simple because the target audience was high level physicists. They tend to go all esoteric, and forget to worry about the mundane things like releasing 3 gigajoules in an uncontrolled fashion, or how to measure an error of a hundred microvolts buried in ten or 15 kV in a few milliseconds.. That article was so they wouldn't need 29 kilovolt resistors. Or a really really large dustpan..
jn
John, the problem is that what the ears are picking up, but what conventional measurements are not, needs to be quantified, converted to a standardised testing regime. The sceptics are too busy wetting their pants, laughing at the snake oil merchants, etc, to get off their bums and implement a decent procedure. Over and over again, suggestions have been made about about improving testing techniques, and these are always met with deathly silence, and zero action - those in the "ascendency" are too lazy, and content, they are perfectly happy with the status quo ...
They exist all right. People with sensitive hearing, or who have attuned their perception to the common problems of audio replay have no trouble hearing the issues. And normal listeners also have no problems in reality -- you ask them if what they heard sounded "real", and to a man they will say, no ...
Good examples of typical, faulty playback occur throughout this video, easily perceived even via a YouTube link: Just How "Absolute" Is Recorded Sound? | Stereophile.com
Good examples of typical, faulty playback occur throughout this video, easily perceived even via a YouTube link: Just How "Absolute" Is Recorded Sound? | Stereophile.com
Well, have a really good listen to that video ... the reproduced sound is "wrong", it's not going to convince anyone -- so, what's making it wrong? And, it's nothing to do with the recording, or the concept that "reproduction can never sound real" - the playback is defective, and is obviously so, for me at least ...
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