Pipe!
I have a scientific knowledge of dielectrics (my professional specialty up until recently was the electrical properties of polymers) and that's why I'm extraordinarily skeptical. The technical claims are pretty bogus and, as usual, no controlled listening tests are given- and anyone who expects evidence is dismissed as a "naysayer." Typical quackery.
I have a scientific knowledge of dielectrics (my professional specialty up until recently was the electrical properties of polymers) and that's why I'm extraordinarily skeptical. The technical claims are pretty bogus and, as usual, no controlled listening tests are given- and anyone who expects evidence is dismissed as a "naysayer." Typical quackery.
YAY...
Hi,
Is this claim about some of the properties of cable insultion technically valid?
"The electric field produced by the signal will polarise the insulation material, introducing distortion. The magnitude of this effect will depend on the polarisibility of the material (loosely correlates with the dielectric constant), the volume and proximity of the material to the electric field, and the strength of the electric field."
SOURCE OF THE QUOTATION
Cheers,😉
Hi,
Is this claim about some of the properties of cable insultion technically valid?
"The electric field produced by the signal will polarise the insulation material, introducing distortion. The magnitude of this effect will depend on the polarisibility of the material (loosely correlates with the dielectric constant), the volume and proximity of the material to the electric field, and the strength of the electric field."
SOURCE OF THE QUOTATION
Cheers,😉
Re: IT OOK THEM 30 YEARS....
Konnichiwa,
Really? I thought it was Pierre Johannet....
If you use this schema (whoever you are) you will not get the best from biasing cables. I have been working on that ever since it came up ages ago (in the pre AA days!) on some newsgroup and have described various "recipies" for biased cables before the most recent craze in the US. And trust me, it takes more than that to get anywhere near to the best possible.
A few hints (as my principles are now commercially applied I cannot give the exact design away), look at the impedance of screen to ground at differing frequencies....
Sayonara
Konnichiwa,
fdegrove said:
Really? I thought it was Pierre Johannet....
fdegrove said:
If you use this schema (whoever you are) you will not get the best from biasing cables. I have been working on that ever since it came up ages ago (in the pre AA days!) on some newsgroup and have described various "recipies" for biased cables before the most recent craze in the US. And trust me, it takes more than that to get anywhere near to the best possible.
A few hints (as my principles are now commercially applied I cannot give the exact design away), look at the impedance of screen to ground at differing frequencies....
Sayonara
Seems to me if a reviewer states he hears a difference, that statement might be considered evidence of a sort, sufficient, even, or to some, to suggest something is at play.
Nor am I sure what a controlled listening test should comprise. I personally cannot hear most A/B differences easily when a stereo setup is changed, say, every minute, five minutes, ten, etc. I remember changing one resistor to a Vishay in an RIAA circuit in a preamp, and heard a difference when I powered the unit up. I probably would not have heard that difference had I not been intimately acquainted with the premod version of the preamp.
But j'digress. It seems to me unless a person has him or herself performed experiments to debunk a claim, all that person can say about the claim is: it might not be true, but I do not know either way. Unless, of course, the person can point to obvious flaws in the stated basis for the claim. But even if the basis is incorrectly stated, something real might be happening even though the claimant missed the target on what that something was.
Sy, perhaps you can answer my question, which I meant seriously as a question. Do dielectrics behave differently when the polarising voltage crosses the from + to - than when that voltage does not (I'm thinking here of a DC blocking coupling cap)?
Nor am I sure what a controlled listening test should comprise. I personally cannot hear most A/B differences easily when a stereo setup is changed, say, every minute, five minutes, ten, etc. I remember changing one resistor to a Vishay in an RIAA circuit in a preamp, and heard a difference when I powered the unit up. I probably would not have heard that difference had I not been intimately acquainted with the premod version of the preamp.
But j'digress. It seems to me unless a person has him or herself performed experiments to debunk a claim, all that person can say about the claim is: it might not be true, but I do not know either way. Unless, of course, the person can point to obvious flaws in the stated basis for the claim. But even if the basis is incorrectly stated, something real might be happening even though the claimant missed the target on what that something was.
Sy, perhaps you can answer my question, which I meant seriously as a question. Do dielectrics behave differently when the polarising voltage crosses the from + to - than when that voltage does not (I'm thinking here of a DC blocking coupling cap)?
Re: YAY...
Konnichiwa,
In terms of exact technical language - no.
Intentiuonally tken, yes. The dominant effect in interconnects is capacitance. Even the consductivity of the conductor has a minimal effect. I found that a nice 2A Schottky diode makes a pretty decent BIPOLAR signal consuctor into a 100K load (being lazy I use diodes in series with the signal generator to "ping" out the polarity of XLR's). If a diode can conduct the siganl with no significant observable distortion at low curret, almost anything (wet piece of string?) will make an adequate conductor, as long as the load end impedance is high.
But exactly that exposes the capacity of the cable and thus the dielectric to the dreaded "memory" effect. Best read Pease, Jung and Marche on dielectric absorbtion in capacitors.
How audible all this is debatable, but I know that in my "Tzaddi" interconnect the application of a bias voltage of 1.2V changes the sound notably, switching the voltage up to 6 or even 12 Volt changes it again. Oh, the dielectric is PTFE, solid, not foamed....
Sayonara
Konnichiwa,
fdegrove said:
In terms of exact technical language - no.
Intentiuonally tken, yes. The dominant effect in interconnects is capacitance. Even the consductivity of the conductor has a minimal effect. I found that a nice 2A Schottky diode makes a pretty decent BIPOLAR signal consuctor into a 100K load (being lazy I use diodes in series with the signal generator to "ping" out the polarity of XLR's). If a diode can conduct the siganl with no significant observable distortion at low curret, almost anything (wet piece of string?) will make an adequate conductor, as long as the load end impedance is high.
But exactly that exposes the capacity of the cable and thus the dielectric to the dreaded "memory" effect. Best read Pease, Jung and Marche on dielectric absorbtion in capacitors.
How audible all this is debatable, but I know that in my "Tzaddi" interconnect the application of a bias voltage of 1.2V changes the sound notably, switching the voltage up to 6 or even 12 Volt changes it again. Oh, the dielectric is PTFE, solid, not foamed....
Sayonara
Die Dikke Berta Ist Da...
Hi,
Congratulations...
You wouldn't happen to know Mr. Johannet's age or the exact date the study was done either?
FYI, it was at the very least 25 years ago which, given the fact it took so long to hit the commercial fan across the pond, it looks as if it does go back to Methusalem as far as I'm concerned.
We should have known....
It's probably much easier to just learn some french and read the original paper...
Cheers, 😉
Hi,
Congratulations...
You wouldn't happen to know Mr. Johannet's age or the exact date the study was done either?
FYI, it was at the very least 25 years ago which, given the fact it took so long to hit the commercial fan across the pond, it looks as if it does go back to Methusalem as far as I'm concerned.
We should have known....
It's probably much easier to just learn some french and read the original paper...
Cheers, 😉
Kuei Yang Wang said:
Hi,
To what do you attribute this audible change?
By the way, what approximate voltage is driving an 8-ohm speaker at 1 watt drive power?
Regards!
Konnichiwa,
To the infinite complexity of the universe and the perversity of it, which invalidates the best laid theories of men, mice and dolphins. I'll be DAMNED if I know WHY. I have gotten MOSt of Mr. Johannets theories and they don't quite wash with me. All I do know is that it works.
2.83V RMS, per definition. Of course, an 8 Ohm speaker is not an 8 ohm resistor.
BTW, while the thread is about speaker cables, I have referred to (line level) interconnects here. In Speaker cables I found "polarisation" to have a lesser effect, lesser enough to leave it out.
Sayonara
serengetiplains said:
To the infinite complexity of the universe and the perversity of it, which invalidates the best laid theories of men, mice and dolphins. I'll be DAMNED if I know WHY. I have gotten MOSt of Mr. Johannets theories and they don't quite wash with me. All I do know is that it works.
serengetiplains said:
2.83V RMS, per definition. Of course, an 8 Ohm speaker is not an 8 ohm resistor.
BTW, while the thread is about speaker cables, I have referred to (line level) interconnects here. In Speaker cables I found "polarisation" to have a lesser effect, lesser enough to leave it out.
Sayonara
Kuei Yang Wang said:
Easy, easy. I'm friendly. (See how jumpy the naysayers have gotten us?) I don't doubt polarising works, I was just wondering as to your best guess why.
A claim a long way from evidence. You can find people who claim to have witnessed the operation of perpetual motion machines. Or, that Peter Belt's so-called electret foils can dramatically change the sound of an audio system- or his claim of audible improvements, complete with testimonials, by putting your photograph in the freezer. There may indeed be something at play, but it's so overwhelmingly probable to be psychological artifact that most rational people will not pay attention until that's controlled for. Remember, this isn't an experiment, this is someone making claims for commercial products that he sells for money.
Depends on what you mean by "behave." If you mean, "will the signal transmission for a signal running from +1V to -1V be the same as the signal transmission for a signal running from 0V to +2V?" then yes.
This not generally correct. It depends on the magnitude and linearity of the polarizability.
SY said:
I'm not sure how to formulate the question I want to ask. Here's asking from another angle: is there anything about the jump from negative polarisation to positive polarisation (-5V to +5V) that differs, say, from a same-voltage increase in polarisation (+250V to +260V)? I guess what I'm asking is whether funny things happen around the zero-line of polarisation.
Cheers.
serengetiplains said:
Not sure exactly who you're referring to here, but I'm not a "naysayer" nor was I "naysaying.,"
What I was addressing were calmart's inferrences which were based on some rather large leaps of logic. I'm sorry, but I find the notion that because condenser microphones sound good and use a bias voltage ergo a cable may also sound good if it uses a bias voltage a bit bizarre from a logical standpoint.
Perhaps. But given that the space charges, molecules, etc. which make up the dielectric are randomly polarized in the absence of an external field, I don't see how there could be something analogous to zero-crossing distortion.
But if there is, the distortion it's producing must be below -145dB as distortion measurements which were made at this level showed no signs of distortion beyond that of the signal generator itself.
se
serengetiplains said:
But in this case, we have a reviewer who said that he didn't hear any difference when comparing the same cables with the DBS unit and without.
se
serengetiplains said:
I'd think the funny things would tend to start happening at the extremes of polarization, where the dielectric starts approaching its breakdown point. Rather like how the funny things start happening in magnetic materials as they're brought closer and closer to saturation.
se
No. As Stevee correctly notes, the "funny" things happen at very high polarizations. Near zero, the dielectric is at its most linear.
Steve Eddy said:
One reviewer, yes, but taking skepticism in hand, to be consistent, why believe what just one reviewer says? The Absolute Sound thought the difference between using and not using DBS was significant enough to award the cable a speaker wire of the year award.
SY said:
So biasing the dielectric on a cable would be rather analogous to DC bias current flowing through a transformer winding, yes?
se
serengetiplains said:
I'm not believing what any reviewer says. I was simply saying that the incident SY was referring to involved a reviewer who said he didn't hear any differnece with the DBS. No more, no less.
Whoop-tee-doo. Some consumer magazine gives some speaker cable an industry cheerleading award that the manufacturer can use to pump up their marketing literature. This proves what exactly?
se
SY said:
But what of actually crossing the zero line? Is there some bump of energy required to opposite-polarise or for that matter to polarise from an initial non-polar state?
Steve Eddy said:
Yes, which, in a transformer, avoids hysteresis loss. Perhaps dielectrics experience something analogous to remanence.
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