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In Reply to: RE: Teflon is cool.... posted by gusser on January 26, 2013 at 13:36:26
"The electrical attributes of Teflon are nil at audio frequencies anyway. So the benefit is strictly mechanical."
Hi gusser,
It's exceedingly difficult to read this falsehood coming from another fellow EE. Steve Bench's site where he shows distortion of dielectrics proves you wrong long ago. I have gone into this time and time again. You fail to keep up with the literature on topics such as epsilon-sub-r distortions, including hysteresis and saturation. It's a real life subject, not in any fantasy land. But this time I will not be handing out all the references for you because you never read them and follow up properly based on that new information. So I will contradict by only saying to you: please get with the program, and let me ignore you as I usually do.
Follow Ups:
And as usual you take my claims way out of context.I did not say anywhere that teflon PC boards don't have specific attributes for electrical signal transmission. I have a lot of microwave experience. Teflon boards are often mandatory in this application.
What I did question is the relevance of these attributes on an audio amplifier circuit.
Now are you going to argue that a teflon PC board make any significant difference over FR4 and G10 for an audio amplifier? I want measurements, not audiophile fokelore. In may day job back in 1999 i even considered using teflon PC boards for some early HDTV digital switchers running at 1.5gbs, 745mhz. However I determined that FR4 is adequate and so has the industry in the past ten years.
You seem to be one of those EE's that never soldered two wires together. Based on your posts you have no concept of practical relevance. That fact that these phenomena are present and even measurable does not make them in issue in every application of electronics. I have no doubt there are research papers relating to the effects you post. But show me research in the consumer or professional audio industry where this is being practiced. And while I do have a lot of respect for Stever Bench, his site is still a hobbiest resource. Show me and IEEE paper that realtes this phenomena to audio circuits and I will accept that.
Edits: 01/28/13
I looked through his site and I don't see anything about teflon tube sockets or PC boards sounding different. Now he does have an excellent article on capacitor dielectrics which I find no fault with at all.But we aren't talking about the sound of different capacitors here are we?
Now before you jump in and try and educate me as to the capacitance between tube socket pins and traces on a PC board, I certainly understand that. Of course there is a measurable capacitance difference between G10 and teflon, between ceramic, phenolic, miconol, and teflon.
But what exactly is that difference in farads and what influence does it have on a typical audio circuit. To be clear I am not saying it doesn't exist. I am asking what audible influence the difference makes based on the signal to noise ratio of the circuit?
Edits: 01/28/13 01/28/13
"But what exactly is that difference in farads and what influence does it have on a typical audio circuit. To be clear I am not saying it doesn't exist. I am asking what audible influence the difference makes based on the signal to noise ratio of the circuit?"
That is the question for all time in audio, isn't it? There it is all in the believability of short or long term impressions. I know wiring makes only a small difference, but I believe it does make a difference. And believe me, people can hear signal to nearly -30dB down in random noise. It's another posting of mine long ago why I think 24 bits sounds better over dithered 16 bits.
If you want to "prove" two things are the same, do DBT's. Proving a difference is equally impossible in small shifts of timbre and time domain performance.
If you refuse to believe that you can hear this small change that often disappears right after using it, that's not a bad position to be in. If you believe in the change occurring but realize the effect is measurably very small, that is another good position. Just as long as we now understand ourselves to be doing one or the other.
But blanket statements for all that we just can't have an audible effect is insulting my intelligence. That PIM occurs only at microwave frequencies and not baseband is just one such example people misinterpret the truth about the real world.
Does skin effect occur at 10hz?
YES it does.
Now show me an application in the history of electrical engineering where it makes any difference.
So is myself or anyone saying skin effect at 10hz is nil wrong?
Note that in the first post you took exception to I did not say teflon has NO effect on audio circuits. I said the effect was NIL.
BTW "nil" is a widely used engineering term. I have seen it used in many papers and PE reports.
Do you know what "parameter"' he is measuring in his scope traces? He refers to the less than perfect traces as symptomatic of "hysteresis" but of what? It seems to be voltage coef of cap but he never states this. If it is, is it sonically significant? The ceramic caps come out bad but what type did he test: NP0? Z5U? etc. You're not curious about his conclusion that the PIO caps that he happened to be evaluating for a client "test" and sound best. Or have his cap test pages changed since I last checked? Or did I miss it?
I have no fault with the idea that dielectrics can make measurable differences in capacitors.
...But what in the world is Bench measuring and are his specific conclusions valid?
A small hint for you all.
So what should I conclude from this? That if I place, say a peice of plastic coated wire inbetween to charged plates, that the plastic will deform? That as in place a charge across a capacitor's leads, the dielectric will deform?
What scale are we talking about here?
The electric field will distort as the charge inside the dielectric is increased. The problem is the same with a spring. It's linear counter-force at the start, but goes similarly nonlinear the more the force on the spring is increased. A balloon is also similar. These are mechanical features of the limits of material memory being nonlinear.
Maxwell's equations neglects all nonlinearity in material and is in fact only correct for case of free space. Dielectrics are mostly assumed linear, with a model neglecting its true nonlinearity. So other experiments are necessary to show this effect. The lack of perfect "memory" in the mechanical nature of dielectrics adds another distortion feature in hysteresis distortion.
Anything that can be seen on a scope with your eyes, such as effects of dielectrics in capacitors, is huge distortion. You can hear it far more than you can see it on an ordinary scope. It's about 3% HD before you can see the bends in a sine wave.
The same effect is there in wire insulators, HV charges on vacuum tube sockets. This is no longer assumed free space anymore through the socket. But it is a far less electric field strength there than inside capacitors. So distortion from these sockets have to be much smaller. In fact, I personally haven't heard any difference in sockets. But I will not be the kind of guy who has to tell off the next guy who thinks there is a difference. I used to think caps would also make no difference, but I hear big differences now and I would not make the same mistake again, I hope. When people can peel the onion back further than I have, who knows what next effect will be noticeable?
I have to see it that way. When people are still saying all amps sound the same, I just leave them. What a waste of time (with aggravation) talking to them. Most people don't say that, but the idea of "parts quality doesn't sound different" is amazingly still pervasive. No part is pure. Even passive devices distort nonlinearly.
If someone threw a file folder out a window of WTC#1, did that reduction in weight prolong the collapse?Yes, it did and given enough resolution you can prove it mathematically.
Now what practical difference did it make in the final result? Was one life saved because of that miniscule delay?
This is the Tube DIY forum. Whatever dielectric compression phenomena exist between Teflon and other standard dielectrics are well below the threshold of audibility and practical measurement. Practical measurement meaning the standard tools used in designing electronic audio products.
Edits: 01/31/13
"Whatever dielectric compression phenomena exist between Teflon and other standard dielectrics are well below the threshold of audibility and practical measurement. Practical measurement meaning the standard tools used in designing electronic audio products."
You have no idea what the threshold of audibility is about in anything. That is one thing I am certain about. Because you can't even design an experiment that removes all other distortions and leaves you with nothing but the one being tested.
When a massless building finally comes to pass, then you can talk about the other small mass loadings. Same with a pure amp. A FRACTION of another type of distortion can be heard in the presence of something very large if they're not too much the same type. And distortion is more than THD and IMD. There's dynamics involved, not just steady state old school measurements. You assume way too much. Even if deck chairs are thrown off the Titanic to slow the sinking, something is still observed in this process: The deck chairs are gone! Conclude at your own peril.
Don't assume the situation hasn't come to pass that stink in small chemical concentration can't be smelly in the presence of pure oxygen, either. This, like your analogy, is also a red herring. You haven't shown anything except how you pass judgment on the truly untested results. There is nothing concrete about your own statements.
It's your judgment and your opinion based on lack of experiencing it. Say it like that and I will agree with you. I have placed no judgment on it as no scientist should. A suggestive idea is what you have. That's all. Heard all the time.
You haven't taught me a thing on this whole escapade. I doubt you will. I have not changed my mind like you won't change yours. That I can guarantee.
"Because you can't even design an experiment that removes all other distortions and leaves you with nothing but the one being tested."You assume I don't know the process and theory of cancellation? Albeit at the levels we are talking about here I doubt it would be very effective.
You say I make flawed statements because I have not tested what I claim.
Fair enough.
But I will say you seem to lack much practical experience in electronics design. I have been in the audio/video/computer design business for 30 years now. That does not count my pre university hobbiest experience. While I cannot say 100% for sure that Teflon tube sockets do not make an audible difference due to lack of trying it, I can fairly accurately predict they don't.
Someone who is strictly a book worm, no matter how highly educated, will not understand that because they have no practical experience to fall on.
Where do you stand in that?
I realize one need not test every theory proposed provided that someone else has and published credible data of their work. But I sincerely doubt I or you will find and credible data that Teflon tube sockets make a audio amplifier sound different. I could be wrong but until I see something to the contrary outside of audiophile listening reports I will stick by my initial conclusion.
And I am not a scientist. Never claimed I was. I am an electrical engineer. I am paid to solve practical problems and get things done. Not ponder these minuscule interactions that occur deep to the right of the decimal point. Unless of course they do make a difference. If you are a scientist then it is your job to do exactly that. And when you discover something that does make a difference in engineering, you report it to us and we the engineering community heed it.
It takes both of us to move technology forward. Always has.
Edits: 02/03/13 02/03/13 02/03/13
I have been involved in engineering audio projects as an amateur for about 40 years (since I was 12 years old). I have no professional experience in audio except to start my own audio transformer business with not enough success soon enough.
I have designed speakers using great measurement tools and simulators available to me. But the design was still from an amateur, and other speaker designers could do more with driver mods than I could. Funny that I would try to modify some highly rated speakers, though.
I have designed and built literally hundreds of amplifiers, SS PP and SE to tube PP and SE. I have experimented with parts cheap and expensive, and find some correlation in price, but something rather disconnected often in the correlation. IOW, you have to try and see what it is every time.
I have a strong background in electrical test and measurement as my day job once was. I am now unemployed as an EE. I am trying to be a better diplomat in my stressed out manner. I have been involved on the internet for about 25 years, since the days of newsgroups like rec.audio.
I also have been into high-end analog, one of the co-designers of Gary Pimm's phono stage. I also have been lately into high rez digital, and have been fascinated more by 24 bit audio over 16 bit than high bit rates. That's another story.
I have for a living done baseband, IF, analog and digital, RF, and microwave circuits. I have designed and analyzed and measured many things. I have done work in microwave metrology. I spent 25 years in a leading electronic test and measurement company as a manufacturing engineer and sometime lab development engineer.
I used to be well known here, but I have been lately trying to be anonymous due to past digressions.
Well, that's a quick positively spoken biography. Then there's my dark side :-)
I won't disclose it here but my memory is pretty good.
If...a dumb ass is in the woods talking and nobody was there to hear him; was what he said still stupid? Assuming there was a foot of snow!
It is a matter of philosophical perspective how you want to conclude anything, if you conclude anything. Me, I'm not sure about anything these days. I do have my bets based on past results and probability. Probably I will die never hearing the effects of teflon sockets. That's only a guess.
Probably I will die never hearing the effects of teflon sockets.
I thought it was really interesting that early on in this thread Gusser specifically called out the unlikely nature that any effect hear was electrical. He said:
The electrical attributes of Teflon are nil at audio frequencies anyway. So the benefit is strictly mechanical.
40 or so posts later the discussion is still on the electrical characteristics of teflon. Why hasn't anyone paid attention to that 800 pound mechanical gorilla in the corner Gusser alluded to?
Tubes tend to be microphonic which means they pick up and amplify vibrations. I like to call it acoustical feedback. Now lets forget whether feedback is good or evil and just accept that it exists. Surely how it is applied (remember it is acoustical feedback) can be altered by the the materials / methods used to couple the tube to the chassis.
dave
There might be a minuscule effect on vibration as I can empirically see that Teflon is better at mechanical damping that ceramic.I completely missed that.
You two guys, Dave and Commentary, do exhibit impressive analysis skills. I sincerely hope both of you put that talent to good use in the real world. Because to spite the fun we are having here, worrying about this level of cause and effect in a tube amp project is rather silly, IMHO.
Edits: 02/03/13
I spoke with my friend, a research psychologist out of Princeton last night. I ask him my toughest questions, and he finally convinced me about the onus of proof about something unproven and that which cannot be unproven (this is where science and religion collide).
If the item cannot be proven over many years, it falls into a default state that nothing yet changes current thinking. Seems obvious to me now. That means all evidence points to all amps sound the same. Science is not involved much in audio at all. It's in this religious state that hasn't been taken seriously to try to be changed by scientists, and for scientists to all agree on.
So, I poke fun at the defects in ABX testing as is and offer a new approach (AAA..AX testing), but no one wants to change that poor discerning old method involving bad human memory. But it would be up to someone to publish a real study showing the evidence has been wrong and that we still can hear different amps apart. No one with true credibility has really taken it up and clearly refuted the old paradigm for sure so we can move on to improve things without that cloud hanging over all high-end amp designers.
So, old school remains valid. Old school ABX remains accepted. Surely, we can do better about this situation, but no one is really going to stake their reputation on it, it simply appears.
That is how I see it, anyway. No need to argue about this too much.
Chances are you will die before that. Is it possible to hear the differences? Yes, but not me. I dont want to, but that is just me. I would choose them such as Yamamoto sockets because they might offer better contact qualities or construction ease. I have seen cracked ceramic sockets because of over-torquing! But I have heard of soft sockets because of over heating. Sound wise to me there is not a pinch of puppy shit between the two. Truth is I miss Cinch sockets they had the bite of a dead snapping turtle!
made by Belton in Micanol are pretty good at biting....
yes and do they sound better than Teflon or Ceramic...hehe???
that may be a different thread than this one...
have fun,
and also thanks for your commentary 'commentary'...
and thanks for your good work Dave Sagle...
-3db
If someone threw a file folder out a window of WTC#1, did that reduction in weight prolong the collapse?
Yes, it did and given enough resolution you can prove it mathematically.
This is just plain silly. Aside from being in very poor taste, how can you be sure your hypothetical file folder wouldn't change the pressure relationship on the structure in a manner that would cause it to fail sooner?
dave
I suppose I should have used the saying "throw deck chairs off the Titanic". Does the passage of time make that more politically correct?Your response only reinforces my point.
What ever the answer is, it's strictly a math exercise that has no bearing on practical events. Just as trying to measure the dielectric compression of the teflon on a tube socket in a tube audio device!
Edits: 01/31/13 01/31/13
Stress? What's that and what can it cause? Why do magnetized transformers saturate? Why do highly stressed electrostatically charged insulators "stretch like a balloon wrt the charge", and what the heck does that mean?
Things to ponder when you're not too old to ask "why?", and your textbook could be seen as really "long in the tooth."
I guess I am still young at 52 in ways.
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