Yes, fully agreed.
Any experience with microphones to record A/B (ABX), end of system in room sound, and compare (Diffmaker, RMAA, Arta etc) ?.
Dan.
Like whom for instance...Its a bit of a throwaway generalisation with no defined targets.
Anyone with way out audiophile beliefs, or are you referring to us cynical ones who poo poo the way out subjective beliefs...
In my case you are pretty safe, I have only worked on boards for fighters not passenger aircraft.
Basically saying it's frustrating to see a lack of interest in developing a methodology for ensuring that the final product, a complete audio system, performs to a certain standard - and can be relied upon to be consistent. The whole process of achieving good sound is so hit and miss, the tremendous variability in PA sound quality is as good an example of this as any - I don't know when I go to a show whether I will come out beaming, or curse the idiots who are hypnotised by the number of dials they can twiddle to screw up the sound ...
Agreed. How is proximity effect induced resistance LTI? It follows dI/dt squared.
It will depend on the scheme used to pick up the chip temp. IR has a sense fet where a cell buried within the matrix is used to monitor the die temp at the cell level. That is very fast compared to outside the package, and even fast compared to built on the chip but to the side.
If the sensor is on the chip but lateral to the power dissipator, there will be a lag based on the thermal diffusion velocity of the silicon.
Note that the thermal conductivity of silicon is also a function of temperature.
JCX is assuming that proximity induced resistance increase is LTI. It is not.
It is very hard to characterize for several reasons.
The full surface of the die does not dissipate. The IR line is effectively about 30% of the die surface. Bipolars are better. Diodes are the best.
Silicon has a temp dependent thermal conductivity.
The temperature dependent parameter they use to monitor the junction temperature will start to recover the instant the dissipation has stopped, so how clean they settle to the sensing current is important.
Some assume incorrectly that the monitor parameter instantly reflects the junction temp.
And then there are the solders, the copper, the epoxy with the thermal masses and diffusion velocities all messing up the ideal.
The vendor numbers are great as a first pass, to get better than that is extremely difficult, and the resultant model change is of diminished returns.
Quite so. All the literature I find relating to switchmode supply inductors and transformers concentrate on characterization of the absolute value of the dissipation, rather than the nature of the resistor vs time.
Why don't you try this: get some small diameter coaxial cable with a braid shield. Make an air core inductor by coiling it nice and tight. Try for about 2 mH.
Measure the inductance vs frequency by using the braid only. You will find the region where the braid's Rs starts to climb. Measure it out to Rs=20 times the dc value.
Repeat this measurement using only the core wire. You will find that Rs will hold off its increase out to a higher frequency. The smaller diameter of the core resists proximity.
Now, for the actual test. Connect a power amp to the braid and core at one end of the coil. Return the power to the amp via the shield only. Sweep the sine from a low freq to the frequency where the Rs of the shield is 20 times the dc value.
Measure the core's voltage to ground (shield return) using a 10 x probe to prevent loading. (you are measuring primary to secondary voltage difference with secondary unloaded.)
What's the waveform look like? It is the IR drop of the shield.
Scott knows this test design.
edit: I have the test schematic elsewhere, but no access to it at the moment. Any Q's, please ask.
jn
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Well Frank,
Let's see the last major projects I worked on were for the Apache Helicopter, Carson Presidential helicopter, Dessault Winglets for a retrofit, B-52 inlet duct replacement parts, all kinds of parts for older KC135 bonded panels that were no longer in production and a nice UAV program for the US Air Force made of carbon/ epoxy composites. Before that I had my own manufacturing and R&D company doing such things as medical devices, a touch screen project about 25 years ago, yes that long ago we were working on touch screen technology, solar panels and a nice solid fuel rocket. So I guess you could say I have been involved in both rocket science and medical device manufacturing among other things. I got a patent in waveguide design applications that covered materials application and mathematical design in 1976 so I have been involved with audio design for 37 years now. Some of what I am doing today I could patent but then I have to give away my design to everyone else to see, I would rather keep it as a trade secret and let others try and figure out what the hell I did and how I did it.
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.
Let's see the last major projects I worked on were for the Apache Helicopter, Carson Presidential helicopter, Dessault Winglets for a retrofit, B-52 inlet duct replacement parts, all kinds of parts for older KC135 bonded panels that were no longer in production and a nice UAV program for the US Air Force made of carbon/ epoxy composites. Before that I had my own manufacturing and R&D company doing such things as medical devices, a touch screen project about 25 years ago, yes that long ago we were working on touch screen technology, solar panels and a nice solid fuel rocket. So I guess you could say I have been involved in both rocket science and medical device manufacturing among other things. I got a patent in waveguide design applications that covered materials application and mathematical design in 1976 so I have been involved with audio design for 37 years now. Some of what I am doing today I could patent but then I have to give away my design to everyone else to see, I would rather keep it as a trade secret and let others try and figure out what the hell I did and how I did it.
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.
Here's the test design.
It's setup so that there are no equipment ground problems, and there is no need for a differential measurement.
If you use too low an inductance value such that you have to go very high in frequency, then there will also be a capacitive coupling inherent in the dielectric of the coax to worry about. While that in itself is purely a linear coupling, it can confound the result simply because it is coupling a distributed primary voltage along the entire length of the winding. Nonetheless, if there is a proximity induced dI/dt squared effect, that will show up in the IR drop of the shield.
jn
It's setup so that there are no equipment ground problems, and there is no need for a differential measurement.
If you use too low an inductance value such that you have to go very high in frequency, then there will also be a capacitive coupling inherent in the dielectric of the coax to worry about. While that in itself is purely a linear coupling, it can confound the result simply because it is coupling a distributed primary voltage along the entire length of the winding. Nonetheless, if there is a proximity induced dI/dt squared effect, that will show up in the IR drop of the shield.
jn
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Getting warmer.....
(JN cleared some of it up, a few posts back from this quote. The dissipation is local due to the lack of lattice constraint in a true fluid. As the system moves into disorder (signal cut), it is predominantly localized dissipation, which is what gave the non-standard pf measurements which do not correlate with norms of transmission equations and expectations)
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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?
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?
It's the danger point of logic being a path, cast in the form of negative proofing, as a core methodology, a core psychological path.
Within it lies circular logic that leads no where, only back to itself. It completes a circle and thus fulfills emotional origins.
For each of us, it lies in wait, ready to pounce on our attempts in discernment, as we reach those limits of discernment. In that, we fall back on fundamentals, and fundamentals definitely include emotional derivatives of our attempts at logic.
If one is trying to stretch their limits, IMO, it is important to bear this thought in mind, otherwise one can lock themselves out of discovery. In other words, 'new' does not mean the same old hammers and nails that exist in the tool kit that one has. If it did exist in the known tool kit.. it would not be new - we'd know it already.
To a certain extent, by logical extrapolation... the mind goes to ground, it attempts emotional circularity and completion at some level (be it minimal intrusion or all encompassing)... when it encounters the truly new. Again, hopefully with more clarity: 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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Nope, I criticize the way out beliefs such as break in boxes...
How can cable be directionalized?
And how is cable broken in...?
Both Audiophile beliefs that don't appear anywhere else in the world of electronics.
Don't start the insult line again, it works both ways...I didn't insult what you do, I commented on cable burn in and the little comments you make regarding the very esoteric side of audiofoolery, and as I said all this silliness detracts from the real issues of sound reproduction, which if they were concentrated on we may learn and move forward, instead we make ourselves the laughing stock by going on about cable directivity...
Fight back with facts then...its nothing personal I'll argue cable directivity and cable burn in with anyone, though I believe what you are saying is don't rock the boat and criticise the way out beliefs...
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Yes, it's to keep the True Believers believing. That's also the reason you insist that any comparisons be done "open" (i.e., not ears-only, but with peeking) so that the comparisons aren't based on just sound.
Marce, the proof for us is in the listening. I would LOVE to be able to easily test for changes in 'break-in' with test equipment, but I have not found anything consistent, yet the underlying physics shows that there is change in metals due to annealing, cryoing, and even just operating. Cryoing and annealing are mostly faster, and that is why they are done, as well.
Ed Simon wrote a paper where he found directionality in some wires, ask him.
Marce, YOUR WORLD of electronics appears to be rather limited, in my opinion..
Ed Simon wrote a paper where he found directionality in some wires, ask him.
Marce, YOUR WORLD of electronics appears to be rather limited, in my opinion..
Since you peek, no, they're not. In fashion audio, ears alone are not trusted, it doesn't move merchandise.
Fundamental physics, my friend, fundamental physics...
Electronics is engineering and does not involve fundamental physics considerations in exploratory form, it only involves engineering rules that take some aspects of fundamental physics and casts them as 'law' so the engineer can build things that are repeatably safe for humans to use.
In the fundamental physics realm, there are no laws, only theory, and theory is subject to change, change that comes from new data. Essentially, in this, 'observation is king'.
To clarify:
Engineering = Dogma
Fundamental Physics = Logic and philosophy.
The trick is to never carry or allow the engineering casting of fundamentals as inviolate laws....into real science.
Thus... to return to your statement/question: people hear or observe directionality in cables.
Engineering has no place in judging this observation as engineering dogma says that no answer exists to this observation...and engineering proceeds to go circular on itself. Dead end, blocked.
So, we can't find it in the engineering tool kit. Nothing there explains it, and only does when it goes square peg and round hole..and forces an answer from the extant tool kit, and issues a furrowed brow shaped papal bull of engineering dogma as the forced proof of non-existence of the observation. which is inherently contradictory, but the engineering tookit does not allow for that observation of self induced circularity.
Due to that circularity in the engineering dogma that finds no answer, we must proceed to science, and to exploration of theory.
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