John Curl's Blowtorch preamplifier part III

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Good point as well. That's a surprisingly high error for a FP32 calculation!

That's 64 bit FP (e-16 =~ -320dB), the problem is unbiased rounding goes all the way even with these slight errors. FFT's of the double precision data has the expected noise floor of -300dB or so but the rounding to 24bits can build in systematic errors (distortion). 32 bit floats have only a 23 bit mantissa, another set of problems.

EDIT - remember the instantaneous dynamic range is determined by the mantissa. 52(3) bits for 64bit is ~1e-16.
 
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The work I am doing in motion control..the most interesting thing is that the most advanced algorithms I am developing involves multiple feedback paths, band limiting, dc servo loops... I am applying what has been done in audio for many decades.

Imagine what could be done if audio design experts (unlike me) got involved.

Imagine a world where someone challenged me to provide references, and I said John Curl.
Jn
 
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That's 64 bit FP (e-16 =~ -320dB), the problem is unbiased rounding goes all the way even with these slight errors. FFT's of the double precision data has the expected noise floor of -300dB or so but the rounding to 24bits can build in systematic errors (distortion). 32 bit floats have only a 23 bit mantissa, another set of problems.

EDIT - remember the instantaneous dynamic range is determined by the mantissa. 52(3) bits for 64bit is ~1e-16.

Thanks, Scott. Makes sense. Total "derp" moment translating between decimal and binary. Mea culpa.
 
JN, I am not surprised that you don't rely on a library of books, either at home or at the office. I am a little disappointed though, I might have been able to buy a textbook that you might rely on, so that we are on the same page more often.
 

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JN, I am not surprised that you don't rely on a library of books, either at home or at the office. I am a little disappointed though, I might have been able to buy a textbook that you might rely on, so that we are on the same page more often.
With respect to what I discuss here, what I know or have access to is far beyond anything that has yet to be printed. I will admit, it is rather weird. I never figured myself being on the leading edge. Being the leading edge on anything, certainly unexpected.
But on the other hand, it is so cool being years beyond state of the art.

The reason I am so very good, is not because I'm best at anything. It is because I have a reasonable understanding of everything, and can talk to those who know more about their expertise than I. In meetings, I know exactly where we need to go, but spend the time asking everyone else how to get there.

That gives them ownership. That is my secret.(which was actually my wife's).
Running a multidisciplinary meeting where every single member feels ownership of the problem...you have no idea how that feels.

I need the best to advance SOTA. I welcome your expertise. As well as all others.

Jn
Ps. Your link to the tail fold octupoles is funny. I wound a super magnet in about ten minutes, it was for some fancy crab cavity stuff. Making the stuff, easy. The physicists don't know how to make the magnets, just what fields they need. I sit in the middle...kinda understand what they want, and know how to build.

The end result of a great collaboration is far more than the sum of the individuals. I welcome your (and others) expertise.
Pps. I feel like sully..."I will be remembered for exactly 208 seconds..."
Oh, forgot. I do have a specific text I rely on.. "This modern clock", Goodrich, 1905. Although, his discussion of lantern pinions w/r to hypocycloids is incorrect. He neglects the trundle diameter.
 
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indra1 said:
Perhaps break in would have discernible effect on improperly annealed (and crap grade) wires?
I guess it is easier to ask 'innocent' questions than estimate the likely magnitude of any effect.

Let me help you. Assume a wire is so bad that it is randomly changing its resistance by 5%. What would be the likely effect on audio if such a wire was used as a domestic interconnect?

scott wurcer said:
BTW the best hams are very savvy and the snake oil does not penetrate far with them.
Yes. Unfortunately some of the rest are just as open to snake oil as some people here - usually magic small antennas which seem to avoid Maxwell's equations, or currents which are not constrained to flow in closed loops.

hhoyt said:
All of this evidence points to the fact that electron flow is not where the energy resides...
You may need to carefully distinguish between energy stored in the fields and energy flowing in the wires. Audio is very low frequency (almost DC). In a circuit with a battery and a resistor most of the energy flows as potential energy of the electrons in the wire, which then gets turned to heat as the electrons lose potential energy by bouncing down past all the dislocations etc. in the resistor. Don't be confused by Poynting's theorem; most people misunderstand what he actually said.
 
john curl said:
Here are two other books that I have found valuable for 'deep' understanding of what is happening in wire and contacts.
Genuine deep understanding has to be preceded by shallow understanding, which thus far appears to be lacking. Otherwise all you have done is learn some new words.

Of course, I have many more books related to physics, as well as engineering.
So have I. So have some others here. So what?
 
...You may need to carefully distinguish between energy stored in the fields and energy flowing in the wires. Audio is very low frequency (almost DC). In a circuit with a battery and a resistor most of the energy flows as potential energy of the electrons in the wire, which then gets turned to heat as the electrons lose potential energy by bouncing down past all the dislocations etc. in the resistor. Don't be confused by Poynting's theorem; most people misunderstand what he actually said.

Indeed, thank you and Scott for following up...my poorly delivered point being some of the effects being bandied about may apply to RF, but maybe not so much at DC or audio frequencies...

Cheers,
Howie
 
... Let me help you...
Again, I am sorry for the misunderstanding. Don't worry, I don't mind signal wires with 5% conductivity tolerance, I use no resistor better than 1%. The quote you made was from my response to your question :
... What is the change in conductance and linearity during this migration? ...
A while ago, I found cited table which shows a 5% difference (on the same industrial grade material between a properly annealed and not) which is incredibly small. I expect any conductance change due to migration and burn in to be smaller than the rolled/annealed figure. And speculated that it seems more likely for anybody who wishes to investigate (KSTR perhaps? I don't currently have the means) to measure a discernible difference from lower grade non annealed wire.

However, I have not looked for anything that may relate to the "linearity" part of your question.
 
Personal message totally OOT to the members of this forum .
I was several time and kindly warned by members from this forum, full of delicacy, about one of my recurring spelling mistakes in English.
I write often WITCH instead of WHICH.

This typo has an explanation, "Witch" is the phonetic transcription of which in my native language. And I often mix up too with *this* word.

I suffer from this kind of problems because i was learned to read with a catastrophic method: "Lectures ?" (Méthode globale), *which* (that) consists of reading a whole word as an object and not a succession of letters: I read at the speed of light, but I dont notice my own mistakes as long as they look familiar to me.

I have to live with this and consider-it as both a chance and a handicap. Please consider only the second part with leniency, not as a lack of culture or respect and accept my apologizes.

Do not take this, neither, for a special taste for magic, that I do not taste more when it comes to electronics or audio, contrary to what some of you might believe ;-)
 
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