Shunyata DTCD (new way to measure power cords) - Page 2

As any former spook can tell you, being a expert in deception and misdirection are prime job requirements.

It's my understanding there is no such thing as a "former spook",...once in the company, always in the company.

But what is the question, isn't it. And, these two gents can also be totally wrong. I doubt they have an certificate of exemption from being wrong or from bs and voodoo, right?

I think the company has the burden of proof of claims, no? So, that should follow with the advocates as well.

The ampacity of a wire in the microsecond regime is based on the guage, the heat capacity of copper, the insulation type, and the starting temperature. I've used #24 awg to support a 400 amp pulse with a time constant of 200 milliseconds and starting at 1.88 Kelvin. Nothing in their writeup or paper conflicts with 14 or 16 awg line cords.

If you consider the technical expertise required to actually do the test, you would change your mind. I do believe however, they really do not know what a non inductive resistor really looks like.

The G2 product from American Super is great stuff, no?? Using liquid nitrogen is soooo much cheaper..

I've never seen that argument. Don't really agree with it either...unless they are extending the system ground to the outlet..

The cited article and paper claim that they developed the test to determine why they could hear the difference in power cords..I find it amazing that nobody is calling them on their blatant statement of audibility. Their electrical testing setup is quite valid, even if they have screwed up on causality..

The electrical part is not an empty claim, it is a reasonably well engineered test. The empty "claim" is the statement that audibility of powercords was the impetus to perform the test..they provide no evidence for that.

Bill...my condolences and best wishes..

I missed the "residual" electricity statement..I assume this probably refers to the inductive and capacitive storage within the cable. This would be the EDC in the equation LC = 1034*EDC..effective dielectric constant of a transmission line that is not fully constrained.


For the actual test, they do not need to provide proof. I fully understand the test and their claims, they are doing good work there.

The audibility claim is an entirely different story. I concur with you.

Shunyata is doing a good and proper test, and their results will indeed correlate with system ground bounce. They have no clue however, that they have mis-attributed line cord energy storage with supply cap charging. It is the ground bounce and line cord coupling to that ground loop that they are accidentally backing into.

ps..The fact is, by using their test setup and methodology, they are attempting to lower the stored inductive energy of their line cord. They believe that by doing so, they allow the caps to charge faster, which is horse-hockey. What they are doing in reality, is reducing the emf field present around the linecord by trying to reduce it's inductance. If and when they learn what they are really doing, then they will realize that it is not the inductance nor the capacitance of the cord that they should reduce, but rather, the external field of the cord. OH, btw..their statement that PFC technology in europe will only increase the need for their cord tech is incorrect. Europe is working to reduce the line cord harmonic draw, not increase it..

Cheers, John

In my view, the end result of all this is retail economics, so Caveat Emptor.


We, as members of this AVS community, are certainly curious as to their claims. However, their product "x", regardless what it is and what they claim it does, either can be beneficial or not. Guthrie, Jung and others have a very good aural baseline and have access to daily use of nearly an absolute transparent control, in which to insert "x", and make that determination.

Yes there is placebo effect, and yes there is expectation bias. As we all know, as one ascends closer to a perfectly transparent system, capable of live levels at full bandwidth without contamination from by-products, any system element change that has the smallest discernible effect becomes easier and easier to resolve.

I've read white papers of fringe products, or more accurately products with fringe claims. I've chuckled while pouring over this stuff, but I've never become judgemental, or the least bit concerned with what may appear to me as being bogus. It's entirely possible that the real reason the product make a small improvement is something that they can't patent, and it's been overlooked by their competition. So they use misdirection toward a secondary design element to protect there un-patentable intellectual property. Or, perhaps their ad copy and white papers are absolutely correct, and we're not intelectually capable to accept claim "y". I don't know.

I realize this is a science forum, and scientific method and measurements are paramount, but it either makes a difference in your system or it doesn't. That is dependant on two things, the situation* in which it was used, and the product itself.

*(Source material, electronics, speaker/room interface, auditory preference)




Maybe I have no idea what I'm talking about,...where am I wrong?

Thanks

If you are basing your statement on proof, I don't see where you would be wrong.

John, the point of the testing and developing this so far unexplained measurement technique was to justify their claims of audibility. Even if their test does show a measured difference, that does not for a moment mean that it will be audible even in a specific case, let a lone the general case of the same PC used in a large range of gear of different design and implementation.

Just based on the current levels and timeframes presented, it was trivial to realize that they did not get these currents from a wall socket and that special equipment was required to perform the test. So for me, what they presented explained everything.

Their test does indeed show a measured difference, and I again have no issue with that. I can (and have) performed the exact same analysis using just the measurements L, C, and R, or cable Z, length, and prop velocity. Their methodology is somewhat rudimentary, but it gave them what they wanted.. Feedback on their cord design which they "believe" correlates to what they claim as audible. Again, I have no problem with that.

What I do find odd, is I stated this:


and your response to that was:


We say the same thing..

As I have stated before, they confuse correlation and causality. It is not the lumped element parameters that they "hear". It is the external magnetic field coupling to a ground loop. And that is extremely system dependent.

Cheers, John

I see that they now have editorial content, rather than just the "Coming Soon" statement.

John, until I saw he email notification for this thread for SS's post, I didn't know they had something more than 'coming soon'. I'll read it when I get the chance.

No problem.

It gave me little more than what I already understood, and it clearly proves the points I've made earlier. They confuse correlation and causality, they present a half baked theoretical understanding (down the wrong path of course), no exact methodology such as the physical design of the "low inductance resistor"...and still that un-considered statement that audibility was initially there so lets devise a theory and test to find the cause...

But don't get me wrong..while Shunyata errs in their theory and understanding, I am quite impressed with the level of technical understanding they present. They have a considerable way to go in understanding both theoretical and practical with respect to electromagnetic field theory.. but I am quite happy with what they have done.

Cheers, John

ps..note that I've mentioned the low inductance resistor several times. When any attempt is being made to measure a rapidly changing current within a low impedance system, it is EXTREMELY important that the current viewing resistor be very, very good. This requires a level of understanding that I believe Shunyata does not have. There is a slight possibility that they somehow used one of my resistor designs, but I think that is of low probablility.

techno-speak..enter here at your own risk...

Assume they use a .01 ohm resistor (arbitrary value of course, but they are trying for low impedance measurement..

200 amps in a microsecond is 200/(10 to the -6th), or 2 times 10 to the 8 amperes per second, written as 2e8.

200 amps will produce a 2 volt signal across the CVR, 7.5% of the drive voltage of 30. (sloppy, but let's go with it)

If the resistor is 1 microhenry, the reactive voltage across it will be: V = L di/dt..

V = 1e-6 times 2e8, or 2e2. 200 volts of reactive voltage added to a 2 volt signal.

For the error voltage to equal the signal of interest, the inductance of the CVR will have to be equal to 10 nanohenries.

Can Shunyata make a 10 nanohenry resistor at .01 ohms? I do not believe so. Can they make one which also has zero loop coupled error from the b dot component?? Definitly not..

I said sloppy, so what would be rigorous? Personally, I'd want both the intrusion and the error to be below 1%. That requires a resistor of value 1.5 milliohms, and a parasitic inductance of less than 100 picohenries. Shunyata cannot do that..nor can they buy it.

I've done 60 picohenries at 4 ohms and 50 watts, dropping to 15 milliohms requires a simple substitution..no big deal...

Good post. I had to re-read it, but yes, good post. However, I need more context relating to your conclusions on Shunyata's, and the author's technical acumen.

Your various assertions;
"They confuse correlation and causality", ...."half baked theoretical understanding", ....."no exact methodology", ...."Shunyata errs in their theory and understanding", ...."They have a considerable way to go in understanding both theoretical and practical with respect to electromagnetic field theory", ..."This requires a level of understanding that I believe Shunyata does not have"

Do you base your assertions about Shunyata, and the individuals that produced this white paper, solely on the data contained in this white paper? Or are these assertions drawn from an aggregate of information that you've attained about Shunyata, and more specifically this author, via many sources?


It appears as if you have a respectable level of intellect in the area in question. So my question to you is would you show all of your cards in ad copy disguised as a white paper?


Thank you.

All this is fine and correct, but it's like talking about how the arrangement of pink flamingos on your front lawn affects the power and position of a hurricane.

That's funny!
(and I agree)

In reading both posts, I thought it odd I would have to repeat myself...but I realized that some of my info is on another thread over at AH. Pardon my confusion and the times where I add onto material you may not have seen..



It is based on what I know about the topic, the way they describe it, the way they approach it, the way they test it, and the way they interpret the results. I do not have any information on the authors or engineers who worked on this project, so my assertions are in no way colored by previous history. However, I do stand by my assertion that they have performed nice and elegant work even if they missed the mark in the initial premise.

Questionable entities:
1. They have assumed that audible differences in line cords is caused by the ability (or lack thereof) to supply current to the power supply at the microsecond level and 200 plus ampere level. This of course requires the wall outlet be capable of providing this.

tech goop alert

Assume 12-3 romex, 50 feet, prop velocity half lightspeed (2nSec/ft),characteristic impedance 100 ohms, load panel infinite current capability, line voltage 100 volts...keep the numbers simple..

Connect a .5 ohm resistor across the line instantly (t = 0)

at t=0, the current in the resistor? 1 ampere, with a 99.5 volt negative V step travelling to the panel.

at t=100 nS, the entire line is charged at a level of .5 volts, the negative 99.5 volts reflects inverted at the load panel and begins back. the line is again charging to 100 volts...but now the load panel current is 1.995 amps.

at t=200 nS, the 99.5 volt hits the load, adding .995 amps to the load, it now has 1.995 amps, and about -98 volts starts the journey to the LP.

At t=400 nS, the load current rises another amp (give or take), load at 3 amps..
At t=600nS, Iload=4

800nS, 5 amps

1 uSec, about 6 amps..granted, it is actually slower, as the add on keeps getting lower and lower.
This is an initial current slew rate of 6 amps per microsecond..225 amps would require almost 40 microseconds to build up. This is governed by the speed of propagation of the romex. I've neglected the 1.7 milliohm per foot for #12, or .17 ohms, that would cause an IR drop of 38 volts...leaving 62 volts available long term, or 124 amps absolute maximum..not 200 in this example.. edit:yes the actual Imax is 100/(.5 + .17), or 149 amps...the IR drop can't result from 200 amps...(I said I'm a nitpicker, even to myself)

Clearly, the test does indeed show the cord's ability to support high current slews, but it's like a V-8 engine on a shopping cart.. This aspect of the test is truly consistent with the miles and miles argument that has been tossed into the fray.

And I've neglected the supply cap ESL, the input transformer parasitic inductance, and the bridge rectifier bulk resistivity..

In essence, the assumption they make of the supply being starved, is inconsistent with the overall system.

Rather, the test they have designed is actually measuring the total energy storage of the cable being tested. For non constrained cables (not coaxial or stripline), this measure is actually a measure of the total magnetic field external to the cable. This external cable is very capable of coupling to the system ground loop. They need to re-focus to that, as that is where the ball is.


On another forum, I stated that they wish to give enough technical to attract the target audience, but not enough to duplicate for a while. I have no problem with that.

They are good, but they are playing with the wrong deck. (note: a full deck of course, just not the correct one.)

If one considers the problem in the "miles and miles" vein, then I agree with you. However, they are altering the external magnetic field of the cable as well as the internal capacitance, and are therefore altering the coupling to the ground loop. That is a different beast entirely..the data they provide via their test is inconsistent with a real life setup.

Cheers, John

You are forgetting several issues in your calculations: The limits of the human ears and the limits of any speaker and room combo, the weakest link in audio, to reproduce those discernible effects.

Amusingly enough, yesterday I got an invitation from Keithley Instruments for the following seminar:



This seminar is designed to help laboratory engineers implement, troubleshoot, and verify pulsed I-V, transient I-V, and general Ultra-Fast I-V measurement systems. The seminar will provide the keys to getting good measurements. Topics to be discussed include system setup, typical measurement limitations, and results from some actual devices.

Those participating in this seminar will learn:

* How to properly connect an Ultra-Fast I-V instrument to a probe station
* Common problems encountered when not properly cabled
* Tips on performance verification at the probe tips
* Limitations in Ultra-Fast I-V including Johnson Noise and others
* Typical examples of Ultra-Fast I-V on sample devices

Seems like a perfect seminar for Shunyata and their "new" pulsed characteristics.

Except I suspect they are not using IC probes...

Interesting how fast "Ultra-Fast" is for various folk.

See you at the seminar! - Don

Sounds like either a wafer probe, die probe, or bed of nails test seminar for ghz processors/chips..


2 amperes in 250 picoseconds with 25 pico resolution is my experience. But I do not consider that "ultrafast".

Some of the guys here do 5 femptosecond stuff.. now thats ultrafast..

Cheers, John

No, I'm not forgetting them.

I mention the speaker room interface frequently when posting, and I strive to improve that interface constantly, both at home and while mixing. I'm a bit over the top with my OCD tendencies regarding analysis of every environment I find myself in and how it relates to the the natural acoustic sources and the manner in which I perceive them. The speaker room interface is akin to the final frontier. There is so much progress lately, and yet I feel we're just begining. I'm all about it. I think about it, read about it, deal with it daily.


As to the limits of the human hearing, I'm well aware of our wonderful ability to resolve inner detail, and grateful that that ability exceeds the best current transducer technologies. I'm also aware that we're fortunate to have some forgiving phschoacoustic abilities, that too serve us well. ie, localization despite dense, reverberant sound fields....etc.

I'm guessing this all began with threat detection, but it sure serves us well in the enjoyment of music reproduction

Ok, you lost me at characteristic impedance

I didn't read the whole thing; Cascade probes, maybe?

I routinely work with 10 - 20 ps edges and sub ps jitter, but not at that kind of current (mA, not A)! As for 5 fs, wow! Linear accelerator (particle physics) stuff?

Too bad all those abilities don't last past our youth which is the time the income level increases to afford better performing equipments. To add to that, humans have arrogance of overestimating own abilities.

It amazed me that a mercury wetted reed relay could make or break in 250 pico. I used it for trr measurements for 5-10 nanosecond recovery diodes.

Now I'm "assisting" another guy to switch 2 kiloamps/12 kilovolts in under 250 nano..a thirty sumptin guy, still larnin.


Whoa. Give that man a ceegar!

Cheers, John

I did warn ya...
Shunyata presents test data on 200 plus amp currents and millionth's of a second.

The analysis I presented states that if you connect a 1/5 ohm resistor to an outlet that is 50 wire feet from the main load panel, the current will never reach 150 amperes because of IR drop in the wire, and the current cannot rise faster than 6 amps per microsecond.

So even if the linecord can do it, the wall outlet cannot.

Cheers, John

edit:
ps..It is not normal to use T-line analysis for such things as line cord/romex speed things. Normally, one would just use the lumped elements L, C, and R. In that case, 200 nH per foot times 50 feet or 10 uH, some unknown capacitance, and calculate the rise of current given a 100 volt step. However, the lumped method is an approximation which ignores the physical size of the system and the prop delay of the cable so can be more exacting...also, that's what they'd expect me to do..

Gotcha, and thanks.

Thinking...... I know the differance that installing a #8awg stranded, 30a, 120v dedicated feed, made in my system. I don't know how much to attribute the ampacity, or that I fed this run to a 5kva Deltec Isolation transformer at my equipment.

What do you think? That big dry type transformer, is there fast response current availability because of energy storage,...storage is the wrong term. But energy availability in the big x-former, massive windings and laminates, being right there at the equipment. Is the energy availability impeded less by my iso method, than if I ran the large awg feed straight to an outlet?

I always felt as if it was akin to a flywheel effect. Since this 1:1 mutual induction circuit isn't perfectly efficiant, that the extra current in the losses, were similiar to a "bias". The line current is higher than the load due to these losses,..I know that. But is there an instantaneous current delivery inherent attribute that I can utilize, compared to a traditional outlet? If there is a benefit, is it due to proximity? What if the iso was @ the panel, prior to 50' or so of wire?

There was a nice improvement with the addition of the circuit and iso unit (2 60v legs), I just don't know how much to attribute to the balanced power or less impeded delivery.

Either way it's nice. I've always felt like I was on to something here but enjoyed the change so much, never thought much more about it.

Thanks

To the OP:
The bait has been taken.

If you have the money, buy the power cords. If not... it doesn't make a difference.

If my son's wife has triplets... I'll suggest names:
Nano, Pico, and Femto (not "fempto").

(background sound of toilet flushing)

Nor I...I'm just a simple country doctor Jim...

If I hadta guess (which I am), I'd think the balanced setup changed more. But that is a guess not based on any data..


Oh you #### nitpicker you...

Yah, ya got me.

Cheers, John

...atto, zepto, yocto...