Audioquest DBS system for cables

[Jinjuku]

Here are some AudioHolic links to in rebuttal to Mr. Low's supposition to AH's "never-ending idiocy over at audioholics, who use a denial of the phenomenon of dielectric involvement as their poster child for snake oil accusations -- but really a poster child for their own ignorance."

Dielectric Absorption of Cables Debunked

Cable Distortion and Dielectric Biasing Debunked

Skin effect relevance in speaker cables

Dr Howard Johnson: About Skin Effect

Current Dependent Phase Shift in Audio Cables?


If Mr Low would be so kind as to post their own engineering notes or either be asked to or forced to redact his statement about the AudioHolics Idiocy (the post has been reported).

 

[amirm]

It's pretty obvious to anyone with a hifi that it sounds better if left turned on.

This is not obvious to me nor something I practice.

Audio is peculiar in that I am unaware (I keep asking to be corrected) of any other single data package that covers 10 octaves. In this way, analog audio is peculiarly vulnerable as pretty much no electrical value is constant over a 10 octave bandwidth.

It is tiny bandwidth as cables and transmission lines go. The low frequencies involved substantially reduces the difficulty in designing a cable for it.

Why forming a cap, leaving one's system turned on, using DBS, reduces distortion is much better understood by engineers with sufficient depth of knowledge in the specific area, though I accept the TRW explanation that a polarized dielectric exhibits less non-linear phase errors that unformed dielectric. Biasing a dielectric to reduce dielectric involvement is a very old idea, even employed in JBL speaker crossovers decades ago.

You probably did not see my response but I actually explained this and it is just two posts above yours! http://www.whatsbestforum.com/showt...tem-for-cables&p=134813&viewfull=1#post134813

As Junjuku also explained, the JBL thing is about capacitors being used in non-polarized configuration. It does not say anything about cables having the same property and measurable effect as I showed for the capacitor.

 

[Jinjuku]

Here is the paper that I pulled the graphic from. My bad for not attributing it in the first post. Mea Culpa.

http://www.ibiblio.org/kuphaldt/socratic/output/animation_pushpull.pdf

 

[Gregadd]

"...This not something that is obvious to me..."
Amir I would respectfully remind you of what you said to me. What you hear is personal to you and of no import in the measure thead.y

 

[amirm]

"...This not something that is obvious to me..."
Amir I would respectfully remind you of what you said to me. What you hear is personal to you and of no import in the measure thead.y

That doesn't apply here. Bill used the notion of leaving equipment on and us believing in that as the basis for the rest of his argument, i.e. we are benefiting from dielectric charging or whatever the means is. I wanted to make sure Bill knew I did not believe nor assume as fact that leaving equipment does that. So if he wants to convince me as he was trying to do, he should use some other basis.

 

[Jinjuku]

I have a suggestion:

AQ get a few golden ears and their DBS system together. They all listen to the cables and report back, by virtue of the sound changing, when the batteries have died on the cable.

Have something setup that monitors the battery disposition and see if by listening alone users know when the batteries have lost their charge.

Use batteries of various charge...

So that's where my thoughts are going in designing a evaluation setup.

 

[Gregadd]

That doesn't apply here. Bill used the notion of leaving equipment on and us believing in that as the basis for the rest of his argument, i.e. we are benefiting from dielectric charging or whatever the means is. I wanted to make sure Bill knew I did not believe nor assume as fact that leaving equipment does that. So if he wants to convince me as he was trying to do, he should use some other basis.

It is the same because your basis of knowlege is your personal experience.

 

[amirm]

It is the same because your basis of knowlege is your personal experience.

Haven't shared any experiences. Commented on Bill saying I have an experience that I have not.

 

[WELquest]

This is not obvious to me nor something I practice.


It is tiny bandwidth as cables and transmission lines go. The low frequencies involved substantially reduces the difficulty in designing a cable for it.


You probably did not see my response but I actually explained this and it is just two posts above yours! http://www.whatsbestforum.com/showt...tem-for-cables&p=134813&viewfull=1#post134813

As Junjuku also explained, the JBL thing is about capacitors being used in non-polarized configuration. It does not say anything about cables having the same property and measurable effect as I showed for the capacitor.

No one can tell you what you do or don't hear -- but this is a surprising fork in the road, that you can't tell there's a difference regarding a hifi being left powered or not, though I suppose with hindsight, I shouldn't be surprised.

On some high-end equipment, the standby function only mutes the output. The power isn't turned off in order to maximize performance. Some other equipment makes a partial on and off division. The better the equipment, the more obvious the particular constipated aggressive 2-dimensional sonic signature of most unformed equipment (though as much of the world knows, different cap materials, circuit board materials, and different wire insulation do not all have the same sonic signature) -- so as a 2nd identical system in not usually available for comparison, the difference is much more likely to be somewhere between noticeable and slap-in-the-ears obvious with better equipment. It's also more obvious with MOSFET amps than bipolar due to the higher voltages. Tubes don't have much dielectric, but the circuits driving them are notable sensitive.

Forming a dielectric takes weeks, and the material returning to almost the original amorphous state also takes weeks. An auditory or otherwise evaluation of the efficacy of charging a dielectric, whether caps in a JBL or Vandersteen crossover, or circuit board material, or within electronic components, or within a cable (which is essentially a long capacitor), requires 2 samples, one of which has been charged for about 2 weeks, and one of which hasn't been charged for 2 weeks.

Why isn't the JBL application about polarizing the dielectric, there's a field? -- Conveniently, putting the potential in-between 2 caps prevents DC from being feed to the amplifier's output.

You wrote that audio bandwidth is very limited -- but you didn't acknowledge or address what I wrote, which is that an audio signal covers 10 octaves. The relevant variable is not bandwidth but octaves and the great variation in electrical variables over that bandwidth. This is also a problem for many other types of signals at incredibly higher frequencies -- A probably weak and too simplistic analogy would be those who believe that a loudspeaker is actually 8 ohms or whatever across the audio band, and so ridiculously believe that they should use a cable with a characteristic impedance of 8 ohms in-between their fraction of an ohm amplifier output impedance, and their "8 ohm" speaker.

Of course they also have no respect for 1/4 wavelengths and such -- but aside from transmission-lines, matching impedances is relevant toward a reduction in reflections at the site of the mismatch -- which is why I build 50 ohm S/P-DIF cables because in our silly world of consumer electronics, by-defintition 50 ohm RCA plugs and jacks are used for 75 ohm connections, so therefor a 50 ohm cable cause 2 less impedance mismatches than does a 75 ohm cable..

The greatest weakness in my speaker analogy is that a loudspeaker is a whole pile of interactive parts -- I'm only using the analogy to try to illuminate surface-only thinking, knowledge which when misapplied makes the amp/speaker interface more rather than less problematic.

Sorry to be wasting everyone's time. I thought I was just venting a bit. Those who hear hear, those who don't can still enjoy music.

 

[WELquest]

Here are some AudioHolic links to in rebuttal to Mr. Low's supposition to AH's "never-ending idiocy over at audioholics, who use a denial of the phenomenon of dielectric involvement as their poster child for snake oil accusations -- but really a poster child for their own ignorance."

Dielectric Absorption of Cables Debunked

Cable Distortion and Dielectric Biasing Debunked

Skin effect relevance in speaker cables

Dr Howard Johnson: About Skin Effect

Current Dependent Phase Shift in Audio Cables?


If Mr Low would be so kind as to post their own engineering notes or either be asked to or forced to redact his statement about the AudiohHolics Idiocy (the post has been reported).

Oh what a simplistic and conveniently blinkered world over there. Gene's recent video is certainly the least entertaining bit of self-importance I've ever suffered through. Still that's my opinion, and was stated as such -- though thank you that your words to me were a lot kinder than mine about what seems to be the fundamentally defective foundation for the audioholics site. It is not based on expanding knowledge, but seems only interested in limiting the scope of investigation, like most any organized religion ever invented.

As for skin-effect. I wrote in reasonable detail on the AQ HDMI cable forum, which I'm sure you saw, about skin-effect being relevant at audio frequencies due to inductance. The link you posted to audioholics's debunking of skin-effect initially bothers me for a mistake I ruthlessly try to prevent in my business, the misapplication of the touchy-felly term "tendency": << It is the tendency of alternating current to flow near the surface of a conductor >> Oh, electrons had a bad hair day ... This is math, not inclination.

The quoted definition of skin-effect, the effect of a reduction in current density away from the surface of a conductor due to delay in the change of the previous magnetic state (the reason skin-effect is proportional to frequency) -- the reason skin-effect keeps you safe in a plane or car as the lightning travels on the skin of the "conductor" while the previous magnetic state keeps you safe inside ... anyway, audioholics states << The skin effect is caused by the self-inductance of the conductor, which causes an increase in the inductive reactance at high frequencies, thus forcing the carriers >>

Why does the article goes on to only discuss the in-a-sense coincidental reduction in current density while ignoring inductance? In my previous comments on the HDMI forum, I stated that both sides of the skin-effect-at-audio-freqncies debate are equally wrong, because the perspective is limited to a single variable (impedance), making the discussion as irrelevant as only only acknowledging loss due to dielectrics, while ignoring other known and measured and specified variables.

OK, I'm irrelevant to those not interested in expanding their world view, using a few limited-usefulness tests to defend themselves from having to consider how little any individual actually knows, not to mention all of civilization's limited knowledge. Time for me to crawl back into my hole and be more productive elsewhere.

 

[Jinjuku]

a cable (which is essentially a long capacitor)

No, it's a cable with properties that follows physics with extremely low energy absorption connected to a high output impedance source that is going to swamp the fluctuating energy state of a non-conductor.

requires 2 samples, one of which has been charged for about 2 weeks, and one of which hasn't been charged for 2 weeks.

Can you give specific examples and the evaluation process?

" Reference: Data for Engineers by Howard Sams

As you can see, Rdielectric is infinitely large [even up to 1MHz compared to the load impedance of a loudspeaker. G is typically on the order of 10^-6 for most materials used for cables and its losses become significant at much higher frequencies than audio (usually in RF regions after heavy skinning has already occurred).

The reason that we usually use conductance (or admittance) for the shunt element, instead of impedance, is that conductances in parallel add directly. Thus another way of showing the dielectric losses (or lack thereof):

For resistors in parallel we know that Rtotal = (R1 * R2) / (R1 + R2). Since G = 1 / R we can rewrite this equation as;

Rtotal = [(1/g1)*(1/g2)]/[(1/g1)+(1/g2)]


Multiplying the numerator and denominator by G1*G2 gives;
1/Rtotal = G1+G2


Gtotal = Gdielectric + Gspeaker where Gspeaker = 1 / Rspeaker. Substituting numbers for a 4 ohm speaker impedance

Gtotal = Gdielectric + Gspeaker 0.25+ 10^-6=.25

where

Rtotal=1/Gtotal > Rtotal = 4 Ohms

Thus the dielectric losses at audio frequencies where the cable is terminated into a low impedance load such as a loudpeaker are insignificant. "

You wrote that audio bandwidth is very limited -- but you didn't acknowledge or address what I wrote, which is that an audio signal covers 10 octaves.

How is 10 Octave audio that we hear relevant to the fact that audio bandwidth is very limited compared to the bandwidths cables are engineered and capable of supporting?

 

[Jinjuku]

Oh what a simplistic and conveniently blinkered world over there. Gene's recent video is certainly the least entertaining bit of self-importance I've ever suffered through. Still that's my opinion, and was stated as such -- though thank you that your words to me were a lot kinder than mine about what seems to be the fundamentally defective foundation for the audioholics site. It is not based on expanding knowledge, but seems only interested in limiting the scope of investigation, like most any organized religion ever invented.

As for skin-effect. I wrote in reasonable detail on the AQ HDMI cable forum, which I'm sure you saw, about skin-effect being relevant at audio frequencies due to inductance. The link you posted to audioholics's debunking of skin-effect initially bothers me for a mistake I ruthlessly try to prevent in my business, the misapplication of the touchy-felly term "tendency": << It is the tendency of alternating current to flow near the surface of a conductor >> Oh, electrons had a bad hair day ... This is math, not inclination.

The quoted definition of skin-effect, the effect of a reduction in current density away from the surface of a conductor due to delay in the change of the previous magnetic state (the reason skin-effect is proportional to frequency) -- the reason skin-effect keeps you safe in a plane or car as the lightning travels on the skin of the "conductor" while the previous magnetic state keeps you safe inside ... anyway, audioholics states << The skin effect is caused by the self-inductance of the conductor, which causes an increase in the inductive reactance at high frequencies, thus forcing the carriers >>

Why does the article goes on to only discuss the in-a-sense coincidental reduction in current density while ignoring inductance? In my previous comments on the HDMI forum, I stated that both sides of the skin-effect-at-audio-freqncies debate are equally wrong, because the perspective is limited to a single variable (impedance), making the discussion as irrelevant as only only acknowledging loss due to dielectrics, while ignoring other known and measured and specified variables.

OK, I'm irrelevant to those not interested in expanding their world view, using a few limited-usefulness tests to defend themselves from having to consider how little any individual actually knows, not to mention all of civilization's limited knowledge. Time for me to crawl back into my hole and be more productive elsewhere.

I saw what you wrote but it was just conjecture... Isn't HDMI CMNR by design? You understand that inductance is effectively nulled and the math proves it.

I can run 2000 foot of 485 serial cable in an industrial environment. There is a crap load of inductance on that run. Just barge loads of it. BUT it's effectively null.

I can run a 10 foot stretch of zip cord in a home environment and there is barely any inductance on that run. And the minimal inductance on that run is so low as to be not a problem at the impedance we are talking about.

I have yet to see anything from you that supports a single point you are trying to make. If what you are insisting is true then it is describable with the universal language of mathematics, measurements, or properly conducted evaluations that trend with the theories.

 

[dallasjustice]

Of course they also have no respect for 1/4 wavelengths and such -- but aside from transmission-lines, matching impedances is relevant toward a reduction in reflections at the site of the mismatch -- which is why I build 50 ohm S/P-DIF cables because in our silly world of consumer electronics, by-defintition 50 ohm RCA plugs and jacks are used for 75 ohm connections, so therefor a 50 ohm cable cause 2 less impedance mismatches than does a 75 ohm cable

I'd love to return this thread back to digital cables. I totally agree with what you are saying here. RCA connectors will NEVER be 75ohms. So there will be reflections which will cause jitter induced by the cable if it's impedance doesn't match the spdif signal. Whether that's audible, who knows? But it's a real problem and serious RF engineers address that problem. For example, Berkeley's USB to AES/spdif converter has a built in "pad" to help increase the "return loss." It's even possible to measure the reduction in reflections using various pad attenuators. IOW, the unwanted reflections can be reduced with sound RF engineering.

My RF engineer buddy Pat once tested a few AES cables I had on his TDR. None of them tested to 110 ohms end-to-end. The best one was 100 ohms. It was a $30 Swiss Gotham AES cable. This is my go to AES cable.


The folks at audioholics confusingly conflate all forms of digital data transmission into "1s and 0s." Although I agree with what they are saying for certain methods like asynchronous USB or Ethernet, I can't agree with them with AES and spdif.

The following is a nonjudgmental "clean question(s)": how is digital audio over HDMI different from AES or Spdif? Is HDMI audio a two way protocol like Ethernet or one way like AES/spdif? Does impedance matching potentially matter like it does over AES or spdif or is it irrelevant like it is over Ethernet or asynchronous USB? Is the HDMI receiver chip asynchronous like all modern xmos USB receiver chips?

Michael.

 

[Gregadd]

If only he had consulted me before posting here. Oh well

 

[amirm]

No one can tell you what you do or don't hear -- but this is a surprising fork in the road, that you can't tell there's a difference regarding a hifi being left powered or not, though I suppose with hindsight, I shouldn't be surprised.

Bill, you just said you can't say that but then you proceed to say it . There are two possibilities here:

1. There is a difference there and I am unable to hear it.

2. There is no difference and hence the reason I don't hear it.

You can't just make one of these true with no data whatsoever.

And by data I don't mean theories. Let's say I tell you that when electrons move in the wire, they cause it to microscopically to move. And that fact disturbs the rest of the cable and hence as the signal goes down the wire the signal is distorted. Therefore I conclude that the wire must be encapsulated in concrete and any wire that is not is causing distortion. I build such a cable and it indeed makes a difference to me. I then show it a bunch of people and they in turn say the same.

Please tell me if you believe the above theory and proof points I have provided.

 

[Gregadd]

There is one other possibility. You heard the difference ,then trained yourself not to hear it. That presumes you were serious when you said that.

 

[amirm]

There is one other possibility. You heard the difference ,then trained yourself not to hear it.

You mean when I turn on my system and play a track that sounds as great as it always has regardless of when I had played it before, the above can be in effect?

 

[Gregadd]

Now you're forcing me to remember all the things you said about sonic memory. My head hurts.

 

[Jinjuku]

The folks at audioholics confusingly conflate all forms of digital data transmission into "1s and 0s." Although I agree with what they are saying for certain methods like asynchronous USB or Ethernet, I can't agree with them with AES and spdif.

I can assure you most at AH understand there are dozens of different encoding techniques... Most of my reading revolves around Metcalf's PAM encoding for my areas of personal interest.

 

[WELquest]

There is one other possibility. You heard the difference ,then trained yourself not to hear it. That presumes you were serious when you said that.

You pertinent comment reminds me of remarkable audio industry anecdote: Many, many years ago, when Gene Pits was the editor of "Audio" magazine, he and Noel Lee of Monster Cable had a disagreement as to whether cables deserved to be a category in the Oct. issue of "Audio", referred to casually as the "Audio Bible" in those days. Gene challenged Noel to prove in double blind ABX testing at an AES convention, that Noel could statistically hear differences, in which case Gene promised to include cables as a category.

In the morning session (as recounted to me by SOTA turntable designer Rodney Herman), Noel was able, to a statistically relevant degree, show that he could hear differences. While at lunch the system setup was changed, and in the afternoon session Noel was unable to meet the statistically relevant criteria. Believers on either side will interpret this as they wish, but it did cause ill-will between the parties -- and Gene did not include cables in the "Audio Bible".

Some months later, Gene Pitts published the infamous "Audio" magazine Greiner article, explaining why audible differences between cable were impossible. When I subsequently spoke with Gene, I asked why his attitude of "benign neglect' (he loved that perspective) had turned into one of attacking cables. He said, a direct quote, not an impression, "because Noel got in my face." Pretty amazing for a public figure to admit. Anyway, Gene went on to say that it was a one-time thing. So, whatever, the subject was dead and over for me.

But, not many months later, Gene published an article by Van Alstine declaring that cables did sound differently, though only because of LCR.

Due to all this brouhaha, I had a conversation with Michael Riggs, later editor of "Stereo Review", though at the time editor of "High Fidelity". Wanting to use an area of debate separate from cables and older than the audio cable debate, I asked about amplifier differences. Michael went on to describe the most remarkable story of how as a lay person, he grew up loving music and hi-fi gear, and heard differences between most everything. He went on to describe that however, when he became a professional and joined the AES, and allowed himself to take an ABX test of amplifier differences. He failed to statistically hear a difference ... so as he recounted the story, he no longer hears differences between amplifiers.

I'm sure some out there are thinking, "well of course, there are no differences," while others are rolling their eyes at Michael's religious-like conversion. Whether Michael was week or strong in coping with a new perspective as he did, is in the eye of the beholder. I think he was weak for not being able to include what he had learned from the ABX experience, which was an important and valuable perspective, without having to deny his own previous knowledge and experience.

It's interesting that Gene Pitts and Michael Riggs had no hesitation regarding publishing reviews of all sound-the-same amplifiers (almost always the closing comment in a Len Feldman amplifier review in "Audio"), and listing most every amplifier made in the Audio Bible, while not acknowledging cables.

Sincerely, Bill