Sterophile new approach to cable measurements

[lsiberian]

Such a waste of effort that could be used elsewhere.

 

[highfigh]

Ah, but according to "them" we are just the non-believers that don't trust our ears.

Wait- I thought we were non-believers because we do trust our ears and not some marketing ploy.

 

[highfigh]

No. But it is safe to conclude that the equipment they chose is incapable of transferring digital information without error in "whatever" test setup they used.

Beyond that, all we can do is guess.

My guess is that the test setup they used may be very valuable.....for testing bit error rates of equipment with ground loop issues with an eye towards fixing the equipment..to make it impervious to choice of interconnect or power cord.

Cheers, John

I was referring to their claims of correcting errors that aren't there. I think we need a sarcasm smiley.

If they actually had ground loops in their system, they should have mentioned that and stated that their cables make ground loops a non-issue. Ground loops are easy enough to fix- why assume people with expensive systems don't have the resources to fix them or that they don't bother?

Being valuable doesn't make it great.

 

[jneutron]

I was referring to their claims of correcting errors that aren't there.

I am certainly willing to believe that the errors were there, and that they measured them.

And I certainly am willing to believe that through some alteration of a line cord, that they were able to change the error rate.

Beyond stating that they were able to change the error rate, they provided no information.

If they actually had ground loops in their system, they should have mentioned that.....

What makes you believe they knew? They did not. They have no clue in that regard.

and stated that their cables make ground loops a non-issue.

They can't. They were unaware of a ground loop issue, and even if they were, they have little understanding of how to correct that and maintain compliance to code.

Ground loops are easy enough to fix- why assume people with expensive systems don't have the resources to fix them or that they don't bother?

No. Ground loops are not easy to fix and still maintain compliance to code and UL..

They do not understand the mechanism which traps unwanted currents so cannot eliminate the trap....they do not understand where the currents go...they do not know how to deal with those currents either in the source component or the sink component..

Without understanding, what is left? Exactly what was presented. No substance we can sink our teeth into.

There may be something to their tests and results, but nothing in what I've seen floats my boat.

Cheers, John

 

[JerryLove]

No. Ground loops are not easy to fix and still maintain compliance to code and UL..

Feel free to correct but: a ground loop occurs when there are two paths to ground in the same circuit and they terminate at grounds with different electrical potentials. In essence, the grounds use the circuit to ground to each other by flowing current through the circuit.

You fix it by dividing the circuit so each new circuit has only one ground. Usually this is done by simply removing one ground from the circuit entirely.

 

[jneutron]

Feel free to correct but: a ground loop occurs when there are two paths to ground in the same circuit and they terminate at grounds with different electrical potentials. In essence, the grounds use the circuit to ground to each other by flowing current through the circuit.

You fix it by dividing the circuit so each new circuit has only one ground. Usually this is done by simply removing one ground from the circuit entirely.

I have colored your points of interest.

Consider a star ground topology. By design, a star ground layout is supposed to extend the same potential to different parts of a circuit. In practice, three physical entities can prevent this from occurring (two closely related, but I said three to bring the count up and make me look smarter than I actually am...

1. IR drop. If one tie to ground is carrying substantial current, there can be an IR drop which will impact the circuit.

2. Reactive "looseness". If one tie to ground is carrying substantial current at a high frequency, the inductive reactance on that wire will cause the potential at the non star end to be loosy-goosy..

3. Faraday's law of induction.
http://hyperphysics.phy-astr.gsu.edu/hbase/HFrame.html
(edit:darn, I hoped it'd go directly to faraday's law of induction...oh well..click E and M, then look for faraday's law of induction..)

Loosly stated, the voltage around a loop is proportional to the negative rate of change of the flux through the loop. The faster the rate of change, the higher the voltage around the loop. So in an environment which has a magnetic flux which is time varying, there will be a specific set of paths from a circuit point to the star ground which will all see the same amount of trapped flux, so can be equipotential. What are the chances that a designer will end up with such a condition? ZERO. (edit: What are my chances? 100%...why? cause I'm good looking)

Now, extend this to a preamp and an amp. Both units tied to the wall ground via an IEC...(remember, we are in a thread discussing the validity of aftermarket power cords, they will all be three prong).

Now, connect the units with an interconnect or two..you have formed a ground loop.

How does one prevent magnetic flux from travelling through that loop and inducing a voltage?
How does one prevent the currents of the units from causing a flux field which is trapped by that loop??? Think power haversines.

How does one prevent the ground current from occurring? ( Remember, you are constrained in that a direct connection of a hot conductor to any metallic surface of the unit must be able to clear the service panel breaker in under two line cycles....code).

Once current is flowing, where does it go?
The path it takes, what is it affecting as a result of IR drop?
What is it affecting because of it's magnetic field?
Both in the source unit, and in the sink unit..
It also happens in balanced input systems...just google the pin 1 problem.

Bill Whitlock of Jensen transformer has some good stuff...but it is only a beginning.

http://www.jensen-transformers.com/an/an004.pdf
Note figure 3. He only speaks about the chassis as the source of the current...and neglects the loop formed by the leads. In general, a very good and very practical paper, regardless of the holes I see..

Cheers, John

 

[Dan Banquer]

If these guys would just admit that its nothing more than jewelry to give you a warm fuzzy feeling about your audio equipment, they would do just fine. People don't buy a Rolex b/c its more "accurate" as telling time than a Casio.

You kneedling novice naysayer, Kosher Chicken Fat will give you the "enlightened" performance you require as a discerning audiophile.
Kosher Chicken fat will negate all ground loops and inductive pickup, it harmonize any output to any input, and send all that fatiguing upper order distortion to below the noise floor where it can't even be measured. Highs will be higher, and lows will be lower, and mids will take on a new clarity.

You must believe or you will banished to audiophile purgatory for life.


d.b.

P.S. If anyone dares to take this post seriously I promise that I will not only laugh you out of this forum but sentence you to 3 months in the "comfy chair".

 

[jneutron]

P.S. If anyone dares to take this post seriously I.......

It is indeed a sad day when verbage such as that requires a disclaimer.

Hey there dude. How are you? Long time no see..

I hope all is well with you and everybody else in your life, all of them of course far more important than you....

Me, doing excellently...thinking seriously of taking the IEEE up on the invite...hmmm....

Cheers, John

 

[lsiberian]

P.S. If anyone dares to take this post seriously I promise that I will not only laugh you out of this forum but sentence you to 3 months in the "comfy chair".

I take this post very seriously.

let's see that "comfy chair"

 

[Dan Banquer]

I take this post very seriously.

let's see that "comfy chair"

Take this you heretic!


http://www.youtube.com/watch?v=CSe38dzJYkY

 

[Dan Banquer]

It is indeed a sad day when verbage such as that requires a disclaimer.

Hey there dude. How are you? Long time no see..

I hope all is well with you and everybody else in your life, all of them of course far more important than you....

Me, doing excellently...thinking seriously of taking the IEEE up on the invite...hmmm....

Cheers, John

All is well here, I still have a job which is a blessing these days.
Contact me off line, I want to here more about this IEEE invite.
d.b.

 

[highfigh]

I am certainly willing to believe that the errors were there, and that they measured them.

And I certainly am willing to believe that through some alteration of a line cord, that they were able to change the error rate.

Beyond stating that they were able to change the error rate, they provided no information.


What makes you believe they knew? They did not. They have no clue in that regard.

They can't. They were unaware of a ground loop issue, and even if they were, they have little understanding of how to correct that and maintain compliance to code.



No. Ground loops are not easy to fix and still maintain compliance to code and UL..

They do not understand the mechanism which traps unwanted currents so cannot eliminate the trap....they do not understand where the currents go...they do not know how to deal with those currents either in the source component or the sink component..

Without understanding, what is left? Exactly what was presented. No substance we can sink our teeth into.

There may be something to their tests and results, but nothing in what I've seen floats my boat.

Cheers, John

You still missed the point of that comment. I meant that in the sense of them making claims that can't be substantiated, they might have said that their cables are so good that even though they couldn't find any errors at first, they caused some, just for the cables to have something to do. Get it now?

Don't separate one half of my sentence and address it independently from the other half. I meant it the way I wrote it. How do you know if they had a clue about it, or not? How do you know if they have any knowledge of code, ground loops or how to eliminate them? I'm at least giving them the benefit of the doubt in that they could possibly contact someone who knows how to make sure none exist, even if I think their findings are bogus.

They may be a cable manufacturer but many people in this field know someone who can determine if ground loops exist.

 

[highfigh]

I have colored your points of interest.

Consider a star ground topology. By design, a star ground layout is supposed to extend the same potential to different parts of a circuit. In practice, three physical entities can prevent this from occurring (two closely related, but I said three to bring the count up and make me look smarter than I actually am...

1. IR drop. If one tie to ground is carrying substantial current, there can be an IR drop which will impact the circuit.

2. Reactive "looseness". If one tie to ground is carrying substantial current at a high frequency, the inductive reactance on that wire will cause the potential at the non star end to be loosy-goosy..

3. Faraday's law of induction.
http://hyperphysics.phy-astr.gsu.edu/hbase/HFrame.html
(edit:darn, I hoped it'd go directly to faraday's law of induction...oh well..click E and M, then look for faraday's law of induction..)

Loosly stated, the voltage around a loop is proportional to the negative rate of change of the flux through the loop. The faster the rate of change, the higher the voltage around the loop. So in an environment which has a magnetic flux which is time varying, there will be a specific set of paths from a circuit point to the star ground which will all see the same amount of trapped flux, so can be equipotential. What are the chances that a designer will end up with such a condition? ZERO. (edit: What are my chances? 100%...why? cause I'm good looking)

Now, extend this to a preamp and an amp. Both units tied to the wall ground via an IEC...(remember, we are in a thread discussing the validity of aftermarket power cords, they will all be three prong).

Now, connect the units with an interconnect or two..you have formed a ground loop.

How does one prevent magnetic flux from travelling through that loop and inducing a voltage?
How does one prevent the currents of the units from causing a flux field which is trapped by that loop??? Think power haversines.

How does one prevent the ground current from occurring? ( Remember, you are constrained in that a direct connection of a hot conductor to any metallic surface of the unit must be able to clear the service panel breaker in under two line cycles....code).

Once current is flowing, where does it go?
The path it takes, what is it affecting as a result of IR drop?
What is it affecting because of it's magnetic field?
Both in the source unit, and in the sink unit..
It also happens in balanced input systems...just google the pin 1 problem.

Bill Whitlock of Jensen transformer has some good stuff...but it is only a beginning.

http://www.jensen-transformers.com/an/an004.pdf
Note figure 3. He only speaks about the chassis as the source of the current...and neglects the loop formed by the leads. In general, a very good and very practical paper, regardless of the holes I see..

Cheers, John

Go to a store that sells audio equipment and you'll find that not everything has a grounded power cord.

 

[highfigh]

I have colored your points of interest.

Consider a star ground topology. By design, a star ground layout is supposed to extend the same potential to different parts of a circuit. In practice, three physical entities can prevent this from occurring (two closely related, but I said three to bring the count up and make me look smarter than I actually am...

1. IR drop. If one tie to ground is carrying substantial current, there can be an IR drop which will impact the circuit.

2. Reactive "looseness". If one tie to ground is carrying substantial current at a high frequency, the inductive reactance on that wire will cause the potential at the non star end to be loosy-goosy..

3. Faraday's law of induction.
http://hyperphysics.phy-astr.gsu.edu/hbase/HFrame.html
(edit:darn, I hoped it'd go directly to faraday's law of induction...oh well..click E and M, then look for faraday's law of induction..)

Loosly stated, the voltage around a loop is proportional to the negative rate of change of the flux through the loop. The faster the rate of change, the higher the voltage around the loop. So in an environment which has a magnetic flux which is time varying, there will be a specific set of paths from a circuit point to the star ground which will all see the same amount of trapped flux, so can be equipotential. What are the chances that a designer will end up with such a condition? ZERO. (edit: What are my chances? 100%...why? cause I'm good looking)

Now, extend this to a preamp and an amp. Both units tied to the wall ground via an IEC...(remember, we are in a thread discussing the validity of aftermarket power cords, they will all be three prong).

Now, connect the units with an interconnect or two..you have formed a ground loop.

How does one prevent magnetic flux from travelling through that loop and inducing a voltage?
How does one prevent the currents of the units from causing a flux field which is trapped by that loop??? Think power haversines.

How does one prevent the ground current from occurring? ( Remember, you are constrained in that a direct connection of a hot conductor to any metallic surface of the unit must be able to clear the service panel breaker in under two line cycles....code).

Once current is flowing, where does it go?
The path it takes, what is it affecting as a result of IR drop?
What is it affecting because of it's magnetic field?
Both in the source unit, and in the sink unit..
It also happens in balanced input systems...just google the pin 1 problem.

Bill Whitlock of Jensen transformer has some good stuff...but it is only a beginning.

http://www.jensen-transformers.com/an/an004.pdf
Note figure 3. He only speaks about the chassis as the source of the current...and neglects the loop formed by the leads. In general, a very good and very practical paper, regardless of the holes I see..

Cheers, John

Are all input/output jacks isolated from the chassis? No. Unplug the leads and the loop goes away.

You may see his paper as full of holes but his practical experience is valid and his methods work.

Re: Pin 1 issues- the common cure is lifting it or using anisolation transformer. A less common cure is using a good isolation transformer.

 

[highfigh]

I have colored your points of interest.

Consider a star ground topology. By design, a star ground layout is supposed to extend the same potential to different parts of a circuit. In practice, three physical entities can prevent this from occurring (two closely related, but I said three to bring the count up and make me look smarter than I actually am...

1. IR drop. If one tie to ground is carrying substantial current, there can be an IR drop which will impact the circuit.

2. Reactive "looseness". If one tie to ground is carrying substantial current at a high frequency, the inductive reactance on that wire will cause the potential at the non star end to be loosy-goosy..

3. Faraday's law of induction.
http://hyperphysics.phy-astr.gsu.edu/hbase/HFrame.html
(edit:darn, I hoped it'd go directly to faraday's law of induction...oh well..click E and M, then look for faraday's law of induction..)

Loosly stated, the voltage around a loop is proportional to the negative rate of change of the flux through the loop. The faster the rate of change, the higher the voltage around the loop. So in an environment which has a magnetic flux which is time varying, there will be a specific set of paths from a circuit point to the star ground which will all see the same amount of trapped flux, so can be equipotential. What are the chances that a designer will end up with such a condition? ZERO. (edit: What are my chances? 100%...why? cause I'm good looking)

Now, extend this to a preamp and an amp. Both units tied to the wall ground via an IEC...(remember, we are in a thread discussing the validity of aftermarket power cords, they will all be three prong).

Now, connect the units with an interconnect or two..you have formed a ground loop.

How does one prevent magnetic flux from travelling through that loop and inducing a voltage?
How does one prevent the currents of the units from causing a flux field which is trapped by that loop??? Think power haversines.

How does one prevent the ground current from occurring? ( Remember, you are constrained in that a direct connection of a hot conductor to any metallic surface of the unit must be able to clear the service panel breaker in under two line cycles....code).

Once current is flowing, where does it go?
The path it takes, what is it affecting as a result of IR drop?
What is it affecting because of it's magnetic field?
Both in the source unit, and in the sink unit..
It also happens in balanced input systems...just google the pin 1 problem.

Bill Whitlock of Jensen transformer has some good stuff...but it is only a beginning.

http://www.jensen-transformers.com/an/an004.pdf
Note figure 3. He only speaks about the chassis as the source of the current...and neglects the loop formed by the leads. In general, a very good and very practical paper, regardless of the holes I see..

Cheers, John

Are all input/output jacks isolated from the chassis? No. Unplug the leads and the loop goes away.

You may see his paper as full of holes but his practical experience is valid and his methods work.

Re: Pin 1 issues- the common cure is lifting it or using anisolation transformer. A less common cure is using a good isolation transformer.

Here's a link to Faraday's Law of Induction:
http://en.wikipedia.org/wiki/Faraday's_law_of_induction

 

[mtrycrafts]

....
Who was it that said "there is no such thing as bad publicity?

Cheers, John

You mean there was a first, and recorded for posterity?

 

[gene]

Umm, I had the opinion that the vendors did their stuff, presented such, and some guy from stereophile wrote about it. Was Stereophile somehow involved? If so, I missed that point.

Absolutely. Stereopile has been pushing the wonders and magic of exotic cables for years through their editorial writeups, so called reviews and advertising for these companies. Its a good business model for them I suppose but its irritating when their writers masturbate scientific principles into the crapola they use to perpetuate the magic.

 

[highfigh]

Absolutely. Stereopile has been pushing the wonders and magic of exotic cables for years through their editorial writeups, so called reviews and advertising for these companies. Its a good business model for them I suppose but its irritating when their writers masturbate scientific principles into the crapola they use to perpetuate the magic.

Is there any chance of you, as an engineer, challenging them to prove their claims and publishing the findings? Maybe this could take place at CES or CEDIA, in a controlled environment, with people who are familiar with critical listening as observers. If their claims are to be believed, they should be willing to prove it to more people in a short time. If it works, great. If not, they should have the cajones to print it in their rag.

I doubt they'd be willing to do it, though.

 

[jneutron]

You still missed the point of that comment. I meant that in the sense of them making claims that can't be substantiated, they might have said that their cables are so good that even though they couldn't find any errors at first, they caused some, just for the cables to have something to do. Get it now?

Actually, I have not missed the point. I took their statement at face value. They spotted bit errors as some specific rate, and when they changed something, the bit error rate dropped. I simply went by what was written.

What is not clear is what the error rate was. Did they mean that when they played the wave file 100 times, they experienced 1 bit error 37% less? As in 67 times they lost 1 bit and then swapped something and then lost 1 bit only in 42 plays?? They provided absolutely no real evidence. What is a lost bit? Is it the loss of an arbitrary bit, or a loss of the LSB? No info...and concluding that there was an audibility difference?? Based on what?? one bit, two, ten, what timeframe???

And technically, their claims do not fall into the "can't be substantiated" category. They fall into the have yet to be substantiated category. We certainly agree that they have not done so, but they claim that they will in the future as the methodology develops (lord knows what that methodology is, or if it even exists). But if they used gear like Gene mentioned, it's simple to duplicate any setup... assuming details are presented..

Don't separate one half of my sentence and address it independently from the other half. I meant it the way I wrote it.

And it was taken as you wrote it. Do not read anything nefarious in my segmentation of your sentence..I did this simply as they were independent entities to me and I split them to address them clearly and cleanly. I never intend to split to alter the perceived content of a poster...if you think that, you are incorrect and I apologize for the way it looked..

How do you know if they had a clue about it, or not?

My own personal experience on the subject. I see their depth of experience, their background, their ad copy, their product line, and I do not see a match to a real understanding of it beyond simple hum.

How do you know if they have any knowledge of code, ground loops or how to eliminate them?

My own personal experience on the subjects. I live with and deal with NEC, with UL approval (and lack of it), with ground loops in environments you would not believe, and I work to eliminate the loops and the sensitivities to such loops as part of my job. In seeing their "output", I do not see that which I would expect.

Very strange situation here...you blast their "output" with a knee jerk reaction (for lack of a better word on my part) but want to give them the benefit of the doubt with respect to technology...and I knee jerk them on their level of technology but give their "output" the benefit of the doubt..

This is very funny to me, as we both in essence are of the same mind..

I'm at least giving them the benefit of the doubt in that they could possibly contact someone who knows how to make sure none exist, even if I think their findings are bogus.

Their output indicated only the one consultant. Quite honestly, I did not find any qualifications when I searched that guy for credentials. If I were a customer, that would concern me..

I remain skeptical of their findings as you do, but since there are certainly physics paths still there as error drivers, I remain open to the possibility that they may in the future present everything for peer review.

They may be a cable manufacturer but many people in this field know someone who can determine if ground loops exist.

The chances of them finding the right guy is rather low. If they were to look up Tom Van Doren, their chances would be 100%. What impressed me about Tom was, over the course of two days, he made only two errors in technical presentation, and both errors were not significant for the topic at the time of presentation.

Cheers, John

 

[jneutron]

Go to a store that sells audio equipment and you'll find that not everything has a grounded power cord.

Understood.

If you go back to my post, you will see the following:

Now, extend this to a preamp and an amp. Both units tied to the wall ground via an IEC...(remember, we are in a thread discussing the validity of aftermarket power cords, they will all be three prong).

I repeat, we are discussing aftermarket power cords. To the best of my knowledge, there are no two prong aftermarket power cords...for the uninitiated, two prong cords can meet code if the unit is double insulated, like lots of simple power tools, toasters, clocks, radios, lamps.. But make sure the unit is listed and approved by an NRTL.

It would be great if someone posted the existance of any two prong aftermarket cords, I'd be interested in looking at them..


Cheers, John