Possible New Way To Measure Power Cord Performance

hearingimpared

reeltrouble1 wrote: »

Leading me back to the rabbit hole, relying on me, and all that is me, and all that will continue to be me, even if there was no more me, what was me will remain as me, and what is you is now me.

RT1

. . . EVERYBODY NOW; I'm Popeye the sailor man!!! Toot toot!!!

steveinaz

I just sharted.

hearingimpared

ROTFLMAO!!! Keiko (Mike) and I were just discussing sharting!!!

Cpyder

98Badger wrote: »

The graphs are meaningless. No scale on the time axis. Take a look at the current axis too. For standard house wiring, 15 or 20 amps will trip the breaker. Definately not real world conditions shown. I call shennanigans.

Ditto. Worthless advertising. Forgetting to label the independent axis isn't an innocent mistake unless the "researchers" are abysmal at their jobs. More likely they purposefully did not label the axis in an attempt to hide something from the reader.

mmadden28

Cpyder wrote: »

Ditto. Worthless advertising. Forgetting to label the independent axis isn't an innocent mistake unless the "researchers" are abysmal at their jobs. More likely they purposefully did not label the axis in an attempt to hide something from the reader.

With the test being only µSecs long, what would/could they be hiding by not showing the µS time scale?

Cpyder

mmadden28 wrote: »

With the test being only µSecs long, what would/could they be hiding by not showing the µS time scale?

Numbers. Units don't mean anything without numbers. They could have labeled the time axis with nanaseconds, minutes, years, etc. It doesn't matter. Without a numbered axis, the information presented is ambiguous because you have no reference to make comparisons.

Take these two very simple graphs I made below. They are representing the exact same data but they look completely different. This is acceptable because the axes are numbered. You can extract the data and make your own rough comparisons. Now, imagine the axes weren't labeled. Could you infer anything about the data presented? Besides the fact that b is larger than a, no. You would have no clue by how much. The graphs could be manipulated to make an insignificant difference seem very significant, which is my suspicion of the data that Shunyata Research is presenting.

vc69

Cpyder wrote: »

Numbers. Units don't mean anything without numbers. They could have labeled the time axis with nanaseconds, minutes, years, etc. It doesn't matter. Without a numbered axis, the information presented is ambiguous because you have no reference to make comparisons.

I like nanaseconds of nannerpuddin.

Put that on a numbered axis.

Cpyder

vc69 wrote: »

I like nanaseconds of nannerpuddin.

Put that on a numbered axis.

Lol, no making fun of my typos!

reeltrouble1

RT1ism---music is about intervals not integers.

markmarc

Shunyata has released the "white paper", along with much more detailed screen shots. One of their employees has been posting on the Steve Hoffman forum and has stated that they are looking for independent 3rd party testing. Hopefully, Raife will get a chance to read and chime in with his thoughts on the additional information.

Once again, I'm curious as to whether this is truly a step forward in quantifying what many believe is true about power cables.
http://www.shunyata.com/Content/DTCD-whitepaper.html
http://www.shunyata.com/Content/DTCD-meas.html

hearingimpared

Thanks for the links Mark. I'm going do some heavy reading when the household is asleep.

markmarc

It's actually pretty short, one of the reasons why I put "white paper" in quotes as I question whether it fits the standard definition of such a report. I'll rely upon Raife to lead us thru techno jungle of EE.

DarqueKnight

markmarc wrote: »

It's actually pretty short, one of the reasons why I put "white paper" in quotes as I question whether it fits the standard definition of such a report.

White papers can be long or short, highly technical or marketing oriented depending on the intended audience. The Shunyata report fits the standard definition of a "commercial" white paper.

To our surprise we found that the rectifier "ontime" was different when different types of power cables were used.

This was the most intriguing part of the article to me.

Further, we found different spectral signatures with different cables.

I found the same thing with my power cable noise spectrum measurements.

After many months of testing we found that the results of the test comparisons were not always consistent and repeatable.

My results were consistent and repeatable. However, the power quality at my home is consistently good, with the typical time of day variations in voltage and line noise.

A year after my 2008 power cable noise studies, I bought 11 PS Audio Statement SC power cables for my home theater system at a substantial discount. By that time, the Statement SC's had been discontinued and there was a lot of talk of counterfeit cables flooding the market. The presence of counterfeit cables was confirmed by PS Audio. The Statement SC cables I purchased were identical in appearance to the Statement cables I purchased from PS Audio. The noise signatures of the new Statement cables were the same as those of the Statement cables I measured a year earlier.

The input voltage from the wall outlet to the amplifier could vary based upon time of day and other loads within the building. The test could vary depending upon the load on the amplifier and the specific heat that the amplifier was generating. For these and other reasons we decided that it would be imperative to create a precision reference test rig that would simulate the power line voltage source and to create a test load that closely simulated the action of a typical power supply that was under load. If we could build such a device it could provide us with test results that were repeatable and calibrated.

I have access to a well equipped electronics laboratory with a stable power supply. However, I preferred to do my power cable noise studies at home because this is the environment in which they would be used and the results would be more meaningful to home users.

jinjuku

DarqueKnight wrote: »

My results were consistent and repeatable. However, the power quality at my home is consistently good, with the typical time of day variations in voltage and line noise.

A year after my 2008 power cable noise studies, I bought 11 PS Audio Statement SC power cables for my home theater system at a substantial discount. By that time, the Statement SC's had been discontinued and there was a lot of talk of counterfeit cables flooding the market. The presence of counterfeit cables was confirmed by PS Audio. The Statement SC cables I purchased were identical in appearance to the Statement cables I purchased from PS Audio. The noise signatures of the new Statement cables were the same as those of the Statement cables I measured a year earlier.



I have access to a well equipped electronics laboratory with a stable power supply. However, I preferred to do my power cable noise studies at home because this is the environment in which they would be used and the results would be more meaningful to home users.

I think if we had you and jneutron (avs member) talking about the points that Shunyata has in that white paper there would be a lot of learning that us non-EE types could soak up in regards just to power cable geometry.

For instance jneutron really is espousing that what they are actually achieving is not so much about power delivery but lower ground loop inductance.

Quoted from Jneutron:

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.

The inductance argument is one argument that I think holds more water than straight up power delivery when it comes to the quality of what is coming out of the speaker.

I am not sure of what to make in the white paper when they say:

"If the standard power cord slows current delivery, doesn't it just take a bit longer to fill the storage capacitors?"

What 'standard' cord are the referring to? They don't make mention of it in the paper. Is it 12/14/16/18awg? Am I to assume it's 6ft. What are the internal terminations like?

"This lead to our experimentation with other types of test equipment not commonly used for cable testing in the context of AC power delivery. For instance, we experimented with TDR (time domain reflectometers) and network cable testers (CAT6) testers in an attempt to identify objective differences between materials. While some of these tests have proven to be useful, there have been none that could objectify the difference between (as a single example among many) a six foot AC power cable -- one being a 16 gauge version and the other being a 14 gauge version. With that relatively short length of wire, the test devices listed above could not distinguish between the two. However, in subjective listening tests the differences were obvious.

Where is the write up on these tests? How where they conducted? What was the testing rig?

"The input voltage from the wall outlet to the amplifier could vary based upon time of day and other loads within the building. The test could vary depending upon the load on the amplifier and the specific heat that the amplifier was generating. For these and other reasons we decided that it would be imperative to create a precision reference test rig that would simulate the power line voltage source and to create a test load that closely simulated the action of a typical power supply that was under load. If we could build such a device it could provide us with test results that were repeatable and calibrated. We could then test a power cable or other AC power device directly without having to run tests on an amplifier and then interpreting the results indirectly. Thus, the concept for the DTCD Analyzer was born."

Does this mean that the cables only have a meaningful difference when not connected to standard power grid? I 100% understand that they were able to measure in the lab and why they had to do it that way, but doesn't leave me with much confidence when plugged into the wall at home. It seems like a paradox of sorts.

Cpyder

FYI (Not quite sure why the formatting got dropped, but the emails are still understandable.)

dear shunyata research,

in reference to the data you presented in this article: http://www.shunyata.com/content/dtcd.html, i am curious as to why you did not number your time axis in either graph presented. Without these numbers, the information presented seems ambiguous because the reader has no reference to make comparisons between the data. Can you please include this information so that i may make more accurate comparisons between your shunyata venom 3 power cables and standard power cables?

Thank you,
michael

hi michael,

the graphs were originally presented with a micro-seconds time axis but caelin felt this may be confusing or distracting the average reader from the point
of the measurements. I brought up the fact that technical people may bring this up so the last i heard he was going to put the micro-second line back in. I
am still in la visiting dealers but i will raise the issue tomorrow and see if our web person can put the time line in the measurement comparison section of
the new web page.

Caelin also just posted a white paper and some technical faq's to answer questions that the more technically oriented people might be asking. Funny thing is
that some people have responded saying there is too much info and for others there is not enough.

http://www.shunyata.com/content/dtcd-whitepaper.html

we also had the editor of audio beat, marc mickelson, to the factory this week to view the device, measurements and results. We will post a link to his photographs
and detailed coverage when it is available.

I will find out more about the time axis getting placed in the measurements tomorrow.

Regards,

grant
shunyata research

hi michael,

i was in los angeles when i received your mail.

After i got back i asked caelin to respond and received this from him:

The scales are identical for the compared cables.
The time scale is 50 microseconds from beginning to end.
The time scale is not printed because it is illegible online.

---

also, we have been accused of dumbing down or simplifying relevant info such as the time scale.

This was a decision based on our knowledge of who the average reader might be and wanting something as complex
as the screen captures posted at the bottom of the white paper to be made readable.

Please let me know if other questions come up.

Regards,

grant samuelsen
shunyata research

Bobsama

Fifty millionths of a second? According to that chart, a "standard black" cable exceeds a 50A draw in well under ten millionths of a second. What they're saying is that there is no difference. Their decision to leave the X axis unnumbered is a sign of very poor marketing and trying to put a smokescreen over the actual difference. Add in the poor quality images and it's just a marketing sham to compare a 16GA or 18GA "standard black cable" to their 12GA "Venom-3".

Krazyz1

While most people can hear the difference with a up graded power cord of any manufacture , it is my belief the battle is only 1/2 won without a quality power conditioner.