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Jan Vigne
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Re: some good links on cable discussion

You guys are bound and determined to have a cable thread, aren't you?

I don't disagree with anyone who believes there are "technical" reasons for the efficacy of thin cables, or thick cables, or multi-stranded cables, or solid core cables, or Litz cables, braided cables, tubular cables, flat cables, ribbon cables, retangular cables or any other sort of cable they might choose. Most of us who ascribe to cables as components believe there will always be a technical reason for the things we hear. We do not find our answers in tea leaves, chicken bones and voodoo shamans. We believe in the value of technical theory and reasoned thought but cannot always find such midground among those who prefer to scream for the blood - and body parts - of the snake oil cable salesperson. As our current election cycle has proven there are goof-ball extremists on the far side of any argument. That those in the middle have such a difficult time agreeing on those things where there should be common ground is regrettable because they are often held apart by those very extremists who wish to do nothing more than shout louder than their opponents.

I'm not familiar enough with Carver's amplifier to discuss what he has done. That Bob Carver is an iconoclastic designer is not in question. The long term value of his thinking might be questioned to some extent since iconoclastic design has often driven his products, IMO, more than longevity and evolution of thought has managed.

I have a feeling the difference between current and voltage sources is more than just "a small amount of additional resistance in the 'current' output type."

If you read Nelson Pass's articles on his current source amplifiers, they represent an entirely unique construction method that cannot be achieved by simply adding resistance to the outputs. If the additional bit of resistance in parallel with the speakers is the answer to "tube sound", based on the thinking that transformer coupled amplifiers have a typically higher output impedance than a direct coupled design, then you would find that thinking falls apart very quickly with just a bit of resoning.

If resistance were the simple answer, anyone running too thin speaker cables over a long run and adding resistance by way of such cables to, say, remote speakers or rear speakers in a surround HT system would be hearing what could be described as "tube like" sound from those remote loactions. That doesn't happen.

Increasing the impedance of a direct coupled output stage by a few tenths of an Ohm isn't remotely the same as the complicated impedance and saturation effects that occur with variations of the signal frequency and current delivery in a transformer coupled amplifier. Nor would the addition of even a few tenths of an Ohm bring the typical direct coupled output stage to the average nominal impedance of a transformer coupled amplifier. Would the addition of a few tenths of an Ohm change the sound of the typical tube amplifier considering it may have a nominal output impedance of 1.0 Ohm or higher? To a small extent yes, depending upon the actual speaker load and its reactance but most listeners aware of the frequency response deviations that result from such high output impedances/reactive loads would agree that change would not make the sound more "tube like" nor would it be more desirable. It would simply result in broader frequency response deviations in the speaker's output.

And placing a relatively large amount of resistance in parallel with a driver doesn't produce "tube like" sound in an electrostat or any other driver. It controls the driver's inherent desire to ring. Try a Zobel network intead.

If you boil the tube sound down to ringing, then I guess you could make such an argument but I'm unaware of anyone who feels this (ringing) is the real answer to why tubes and transistors seldom sound alike. The typically high output impedance of a tube amp results in a lower damping factor than the infamous and fabulously high 1000:1 Bob Carver has promoted for the last three decades, but once again that is not the answer to why tubes tend to have more "air" than transistors.

A solid state amplifier driving a pair of electrostatic panels will still sound like a solid state amplifier and a Quad II-forty will always sound sweeter on a pair of 57's or ESL's.

As to magnet wire suffering less from "skin effect", first of all, I think you are confusing magnet wire and solid core wire on a basic level. This may be just a matter of terminology in some cases, however, the distinction should be made when you get around to discussing "skin effect". Either solid core cable or magnet wire can be had in such a gauge that skin effect could be a very real consideration. However, to the cable naysyers, this would only be a consideration when the signal has far exceeded the frequency range where audio signals travel. And so the very mention of skin effect in a cable thread is likely to draw harsh criticism from those who would have all cables be alike if they measure alike at audio frequencies. The implication that skin effect is relevant at audio frequencies will result in the "engineers" in the crowd questioning your education and your sanity. Therefore, I prefer not to venture down the path of whatever might draw such criticism as no opinions will be changed by the mention of such "voodoo" thinking. I use thin cables is about all I will say on that matter.

The conductor legs are spaced apart and are sufficient to carry the required current and voltage in my system. Unlike the unwieldy 12 A.W.G. solid core "anti-cable" cable sold at fairly steep mark up for simple magnet wire with spades attached, the dielectric on my cables remains thin yet protected by another thin layer of a relatively benign material. I use this cable for both interconnects and speaker cables. This is a major difference between my thin cables and the average audiophile cable. In this area I readily admit these thin DIY cables are not for everyone as they are not going to withstand the abuse heaped on too many cables by too many audiophiles. Nor will they appeal to the cables as jewelry crowd. In my system, for what I value, and for a few friends who are also using essentially the same cables, they work as desired despite all the reasons they might not.

scottgardner
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Re: some good links on cable discussion


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You guys are bound and determined to have a cable thread, aren't you?

This already is a cable thread, no?


Quote:
I have a feeling the difference between current and voltage sources is more than just "a small amount of additional resistance in the 'current' output type."

You're probably correct. All I could determine it that there is one additional ohm in that type. You make some very good arguments against what I have said.

I admit I am not an EE. I guess I am trying to start the discussion (again) to see if/what the current reasoning is for these "different" cable types. There must be some logical reasons why these cables have a positive effect.

If you are determined not to have this discussion I'll let it drop.

scottgardner
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Re: some good links on cable discussion

Maybe we can shift out of argument mode and into debate mode?

Jan Vigne
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Re: some good links on cable discussion

I didn't know we were in argument mode. Scott, though others may question what I'm about to say, I have always believed in a spirited debate within a thread. I have an Italian heritage so I can debate till the cows come home and with quite a determination to prove my point. We can go quite far within the debate and still remain respectful of the other. If it reaches the point where lines are crossed - which is possible in some threads - then the thread is the limit of that debate. When the next thread comes along, we start fresh and there are no grudges to settle.

As I've said here, we get along when we all decide to get along. No grudges, no hard feelings. You might learn to be wary of any member but approach each as if they had not offended you yesterday. The forum will be better for it.

scottgardner
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Re: some good links on cable discussion

Cool.

So there must have been some reasoning that led you to try thin cables. Do you care to elaborate further?

"il passato

RGibran
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Re: some good links on cable discussion

30 ga. Thin Wire pics from our members DIY galleries. Nice work

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Re: some good links on cable discussion

Very tidy work.

Looks like DIY Nordost with the number of conductors present.

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Re: some good links on cable discussion


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I didn't know we were in argument mode. Scott, though others may question what I'm about to say, I have always believed in a spirited debate within a thread. I have an Italian heritage so I can debate till the cows come home and with quite a determination to prove my point. We can go quite far within the debate and still remain respectful of the other. If it reaches the point where lines are crossed - which is possible in some threads - then the thread is the limit of that debate. When the next thread comes along, we start fresh and there are no grudges to settle.

As I've said here, we get along when we all decide to get along. No grudges, no hard feelings. You might learn to be wary of any member but approach each as if they had not offended you yesterday. The forum will be better for it.

Jan, do you have the link to that thin cable thread? I cannot find it .. but would love to build some of my own.

Thanks for any help.

Jan Vigne
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Re: some good links on cable discussion

Here's the page where the threads exist, it was split into two threads with some dicontinuity due to upd's interruptions.

http://forum.stereophile.com/forum/postlist.php?Cat=0&Board=tweaks&page=8

I'm not trying to be unhelpful but I doubt I'll get photos of my cables posted any time soon. A few weeks ago my old computer crashed and I had to buy a new unit. I am finding out many of the programs that worked with XP on my old computer or even work with Vista on many new computers are not compatible with Vista 64 bit, which is, of course, what is on my new computer.

Says I, "Will I have any problems with old software not mating well with this computer?"

Says the salesperson, "None that I can think of, everything should work fine."

AHEM!

I'm loading software slowly as numerous additions have caused my new computer to have problems. I just haven't reached the point where I've reloaded the software/drivers for my camera.

Otherwise, if you can imagine a piece of 4" wide blue masking tape with two very thin strands of wire poking out the ends of the tape, that's my speaker cable. They are a bit more attractive and functional than how that reads, but not by much. Since my current speakers are DIY the cables are hardwired to my drivers and the only bare copper is at the amplifier end.

The IC's are quite similar and look more or less like those in the above linked photos. I use different RCA's than those shown in the photos and still use the blue masking tape but the basic idea is presented well in the photos. For my CD players, tuners, etc, I use only one conductor to the hot side of the RCA and another conductor to the ground of the pre amp. The cartridge has one continuous four conductor cable from the cartridge to the phono input.

Some discussion of the cables is included in the two above linked threads.

ncdrawl
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Re: some good links on cable discussion

thanks, Jan.

Quote:
Here's the page where the threads exist, it was split into two threads with some dicontinuity due to upd's interruptions.

http://forum.stereophile.com/forum/postlist.php?Cat=0&Board=tweaks&page=8

I'm not trying to be unhelpful but I doubt I'll get photos of my cables posted any time soon. A few weeks ago my old computer crashed and I had to buy a new unit. I am finding out many of the programs that worked with XP on my old computer or even work with Vista on many new computers are not compatible with Vista 64 bit, which is, of course, what is on my new computer.

Says I, "Will I have any problems with old software not mating well with this computer?"

Says the salesperson, "None that I can think of, everything should work fine."

AHEM!

I'm loading software slowly as numerous additions have caused my new computer to have problems. I just haven't reached the point where I've reloaded the software/drivers for my camera.

Otherwise, if you can imagine a piece of 4" wide blue masking tape with two very thin strands of wire poking out the ends of the tape, that's my speaker cable. They are a bit more attractive and functional than how that reads, but not by much. Since my current speakers are DIY the cables are hardwired to my drivers and the only bare copper is at the amplifier end.

The IC's are quite similar and look more or less like those in the above linked photos. I use different RCA's than those shown in the photos and still use the blue masking tape but the basic idea is presented well in the photos. For my CD players, tuners, etc, I use only one conductor to the hot side of the RCA and another conductor to the ground of the pre amp. The cartridge has one continuous four conductor cable from the cartridge to the phono input.

Some discussion of the cables is included in the two above linked threads.

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Re: some good links on cable discussion


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There must be some logical reasons why these cables have a positive effect.

Two article in our website archives attempt to answer this question. First see an essay I wrote some years ago at www.stereophile.com/asweseeit/84 , then a technical feature from Professor Malcolm Hawksford from England's University of Essex at www.stereophile.com/reference/1095cable.

John Atkinson
Editor, Stereophile

Jan Vigne
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Re: some good links on cable discussion


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Now allow the applied signal to be suddenly switched off. The field between the conductors collapses rapidly, thus cutting off the signal energy being fed radially into the conductors. However, the low velocity and high attenuation of the loss wave represents a lossy-energy reservoir, where the time for the wave to decay to insignificance as it propagates into the interior of the conductor is nontrivial by audio standards. The E-Barσ field within the conductor can be visualized as many "strands" of the E-Bar field, as shown in fig.4.

The error voltage, Vint, appearing across the ends of each thread due to the internal conductor impedance, is calculated by multiplying the E-Barσ field by the cable length L (though strictly this should be an integral performed over each elemental length of the cable). Because the field propagates slowly, this summation is actually an average taken over a time window that extends over a short history of the loss field. Consequently, when the generator stops, the error signal across each conductor does not collapse instantaneously. Instead, the conductor momentarily becomes the generator, and a small time-smeared transient residual occurs as the locally stored energy within each conductor dissipates to insignificance. To this voltage must be added the generally more dominant induced voltage, Vext, arising from the changing external magnetic field. Together, they constitute an error voltage Vε = Vint + Vext. Assuming the two conductors are symmetrical, then the load voltage VL is related to the generator voltage Vg by VL = Vg

Jan Vigne
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Re: some good links on cable discussion

I just thought I'd drop this in this thread in case anyone is thinking of experimenting with these thin cables. Yesterday I went up to Wiley, TX to visit a friend who has been using the DIY cables made with tape and 30 AWG magnet wire. He has been using the cables with the RS solderless RCA's for about six months or more. A good deal came his way when a deal on a Benz cartridge fell through and in the process he picked up a pair of Eichmann Bullet RCA's along with a pair of Linn cables (Black's, I guess this is Linn's basic cable retailing for approx. $100, http://www.linn.co.uk/Black_Interconnect_Cable).

The Linn cables replaced the DIY's between his Rogue pre amp and his McIntosh power amplifier. His LP12 (Ittok/Benz S) came equipped with the Linn Black cables so he was hoping for a synergistic match with the additional Linn cable. His Rega Saturn has the DIY's in place. He also runs the thin cables to his Gallo's Ref. 3's though here he has added an additional strand of 26 AWG fine silver wire in addition to the + side magnet wire. The Linn cables didn't fare well against the DIY's when installed between the pre and power amp or in place on the Saturn offering more bloated images and less correct definition of timbre and pacing. Toe tapping and general interest in the music was reduced by several measures and the music became more homogenized with the DIY's offering more individualized performers playing better together.

OK, $100 cables aren't necessarily high end but they are Linn products so we expected a bit more from them particularly in the area of timbre and pacing. So, the DIY's went back in the system for another listen and then came back out for the change to the Eichmann Bullet RCA terminations. The RS connectors still fared well against the more expensive Bullets but the Eichmanns were a definite improvement in most vital areas other than initial attack where the RS's still held a slight edge. But "edge" is were the RS's failed also. The Bullets wiped the proverbial window clean of the slight glare in the upper mids the RS's impart on the signal. We both agreed the slight amount of edge imparted by the el-cheapo RS RCA's was the sort you won't notice until it's removed and the DIY's have fared well against other cables costing up to $500 per meter pair. With the 30 AWG magnet wire terminated in Eichmann Bullets in place our first selection, Telarc's "Fanfare for the Common Man", easily displayed the differences and the improvements in ambient hall sound and reverberant decay afford by the Bullets. You can insert your favorite and numerous high end adjectives here for the overall sound quality improvement made by the switch to the Bullets. The music was simply more engaging with the Bullets in place.

Bottom line, if you're going to try these cables and find them interesting with the super cheap RS connectors, step up to the Eichmann RCA's and the cable improves by an order of magnitude. It's only two sets of ears so far but we both agree the Bullets are excellent products sold for a minimal investment.

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Re: some good links on cable discussion

From my point of view, the whole discussion on interconnects is a huge joke, in the context of high-end audio.

Any engineer worth spit will tell you that unbalanced connections between pieces of equipment really have no place in high-end audio at all.

Unbalanced connections are subject to RF interference, ultrasonic oscillation, and ground-loop problems, to varying degrees depending on the internal circuit design and grounding scheme used in the units in question.

All of these problems (and the resulting degradation in sound quality that may result) are TOTALLY ELIMINATED when using BALANCED interconnections!! ALL balanced interconnects, regardless of construction or length, are absolutely free of sonic variations or problems as long as they are constructed using XLRs with a grounded metal shell and standard AES cable.

I am sure that some doik is going to say that his Megafromper 99 super-diddly pure tungsten or enriched plutonium balanced cable is superior to some other one; let me say in advance...BULLSHIT!!!!!!! Balanced is balanced is free of problems; all essentially perfect.

In my mind, if it isn't balanced, it's a second-rate design, and doesn't even deserve serious consideration as a high-end piece of equipment.

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Re: some good links on cable discussion

"RFI" is actually rarely an issue in unbalanced cables. I spent 30 years building cables with all sorts of connectors and exotic cable stock, and never could find a real RFI problem there except in the rare cases where one lived in very close proximity to a commercial or ham radio transmitter with high power radiation.

The term "microphonic, while it is not quite the right word, does come close to describing what I did observe in my laboratory.

The output of a piece of equipment has a complex source impedance consisting of distributed capacitance, inductance, and resistance; so does the interconnect; so does the piece of equipment receiving the signal. Mathematical analysis of the complex network thus formed is essentially impossible, because the precise values of inductance and capacitance for the source and load are known (and can be known) only approximately due to their distributed and complex form under actual signal conditions.

In any case, the various frequencies and amplitudes of the audio signal can momentarily excite oscillations or "ringing" of various amplitudes and durations in such a network; and I have observed them in the laboratory using a wide-bandwidth communications systems analyzer and/or a spectrum analyzer. Many of these are ultrasonic, which means they are not audible except to the extent that they "mask" or modify the audible signal, or re-bias the tubes or transistors into non-linear modes of operation.

The insistence of certain people on touting silver, ultra-pure copper, or various exotic materials for cable construction identifies these people as either being totally ignorant of basic physical principles, or willing to ignore them for their own commercial purposes. In any case, none of that has any significant effect on the efficacy of a cable. Various DIELECTRIC materials (teflon, PVC, etc.) certainly have an effect on the capacitance and inductance of a cable, but that is a separate issue.

In any case 98% of the discussion I see here is way way off of the mark if we are talking about the audible effects of interconnects in audio. I have never seen so many long-winded dissertations on technical subjects in which the speaker is obviously unqualified and lacks understanding of the basics.

Jan Vigne
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Re: some good links on cable discussion


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The insistence of certain people on touting silver, ultra-pure copper, or various exotic materials for cable construction identifies these people as either being totally ignorant of basic physical principles ...

Not unexpectedly I assume, I would have to disagree with most everything you've posted here. However, if you choose to narrow your search down to only those things you already know you can find, you'll just about always find the answer you wanted in the first place. If you're happy with where you are and where you've chosen to remain, you get to live for another day without my interference. You might be happy to know, however, I do agree that single ended interconencts have no place in a high end system where the owner has spent countless dollars trying to achieve a lower noise floor while still using RCA plugs and I consider most audio jewlery to be less than beneficial to the sound quality of the connection. RFI? I run several unsheilded ic's and have no apparent problem. That doesn't mean what I can't hear isn't still there.

Suggesting that the innumerable listeners who can detect qualitative differences between cables, balanced or not, are all a group of ignorant fools is IMO saying more about your argument than it is about their's. This argument has been going on now for 30 years, to continue to insist I must hear only what you cannot isn't rational IMO. You can have your partisan opinion, I realize how difficult it must be for many people to think something they've never thought before, but I don't care for any piece of that pie.

commsysman
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Re: some good links on cable discussion

As I have said before, Jan; if you ever agree with anything that I say, I will be forced to re-examine it for serious flaws or fundamental problems.

The other side of that coin, of course, is that your dissent or disagreement profoundly reassures me of the accuracy of my statements.

And of course, if you were to properly understand what I said above, you would implicitly understand that OF COURSE there are audible differences between different unbalanced cables in a specific situation; we all tend to hear those differences because, cables having different RLC values, a cable change varies the entire network characteristic and produces a different (and probably audible) result.

It demonstrates a complete misunderstanding of my comments when you make statements that suggest that I am taking some sort of "no audible differences" position; that is the exact opposite of what my comments suggest. Perhaps on a second or 3rd reading you may better understand what I said.

By the way; you constantly love to complain that I am somehow calling this group or that group "ignorant fools", and then reprimanding me for it. I have NEVER called anyone or any group by such a derogatory name; I don't do that, so kindly quit accusing me of doing so. There is a big difference between alleging an ignorance of a specific fact
or facts and calling people "fools".

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Re: some good links on cable discussion

Seems a short trip from "ignorant" to "ignorant fools" in the context of your post.

However, you are now puting words into my post that I never placed there. I don't see anything in my reply that you could honestly take as putting you in a "no audible differences" position. Quite clearly I think you are actually overstating the degree to which simple RLC values can influence the sort of changes most of us hear when switching cables.

As you say, if you would ever take the time to think about what I post rather than just kneejerking your way to an insulting response, you would see what I've said has little if anything to do with your reply.

If resistance is so minimal in a decent ic cable, even the freebie stuff that comes with your $59 DVD player, that it becomes irrelevant, which it is and has been for decades, then R has little to nothing to do with the qualitiative changes in sound quality that result from a cable change. Most modern cables used in audio have negligible inductance so that's not an answer either. Capacitance alone by most definitions cannot account for the influence all cables exert on the end result. If these simple values were the answer to the infuence of cables within the context of each system, then there wouldn't be any reason to continue on with new cable design - unless now you want us to believe all cable manufacturers are ... wait, it's coming ... "charlatans" and "whores" - or just ignorant of "the facts" as you see them.

Once again, by what I take as your estimation of the cable situation, we could come up with a handful of cable designs meant to fit a few generic requirements and we could all go home and not think about this. I know you'll claim I have totally misunderstood and misrepresented your position but this is what you seem to be saying as I read it. Poor dumb me, I just am not on your level when it comes to the intricacies of how you twist a sentence after it's been responded to. What am I to do other than wait for you to tell me what you actually meant that you just didn't say with clarity in the first place?

Virtually no high end cable manufacturer/designer provides RLC specs on their products - I know, that proves they don't know what they're doing, eh? Oh, no, you didn't say that either so I better not accuse you of being in any camp you couldn't find with the aid of a compass and following the bullshit trail you drop along the path.

JA, a man rather highly dedicated to understanding how technical measurements influence perceived sound quality, doesn't bother taking meaurements of cables reviewed by Stereophile. So I have to note Stereophile hasn't published such a simplified version of how cables operate as you apparently have figured out. Why do you suppose that would be? Ignorance? That puts us back at the question you don't care to answer, do you suppose JA and the Stereohpile staff just aren't smart enough to figure out this component to component variability with cables? Or, are they just shills for the cable companies?

What, you didn't say either of those things? Well, I'll be damned!

The cable shouting matches go on and on after all these decades. If it were so simple to conclude it all comes down to RLC and we'll discuss dielectrics in a subsequent post, don't you think someone other than you might have figured this out without your help?

Of course, I understand a cable becomes part of and therefore an influence on the circuits of the mating components. In case you hadn't kept up, that's where the pro-cable forces began their own reasoning three decades ago when they first noticed the influence of cables. Back in the late '70's and early '80's cable proponents began trying to get a handle on just how much influence the simplest technical values had on the tremendous changes they were hearing.

So, congratulations, you've managed to only be 30 years behind the curve of cable theory.

Unfortunately, your ideas are outdated and have little to do with the thinking behind even low priced cables of today - or even twenty years ago. You're about at the point where you might think a mechanical distributor isn't sufficient for a modern automobile engine. Just keep working on this cable issue, there's a lot to catch up on that has occured over the last three decades that you have either ignored or chosen not to consider.

But, if this RLC thing is what makes you feel better about yourself and gives you the impression you are first person to so fully understand cable theory while so many others struggle with the very nature of plugging "A" into "B", well then, you can put on your snuggly jammies with the feet in them tonight and sleep better knowing you've outsmarted an entire industry. Nice going!

Where do you expect you'll be in another ten years? Up to about 1985? Maybe considering mono-crystals?

Jan Vigne
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Re: some good links on cable discussion

Why did you restart this thread after three months? You just thought we'd all benefit from your brilliance?

commsysman
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Re: some good links on cable discussion

Congratulations on that last post. It was under 10,000 words and was completely understandable; you are making progress.

Jan Vigne
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Re: some good links on cable discussion

I wish I could say the same for you.

But I can't.

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Re: some good links on cable discussion

Thanks! for the links.

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Re: some good links on cable discussion


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From my point of view, the whole discussion on interconnects is a huge joke, in the context of high-end audio.


For me, a lot of it is actually accurate. Unfortunately, there is indeed a lot of garbage bandied about that has nothing to do with reality, and the typical user is unable to distinguish the difference.

Quote:
Any engineer worth spit will tell you that unbalanced connections between pieces of equipment really have no place in high-end audio at all.


Well, it can be done quite well using unbalanced, but there are many times mitigating factors which unbalanced is more susceptible to. I do agree in principal that balanced is much better.

Quote:
Unbalanced connections are subject to RF interference, ultrasonic oscillation, and ground-loop problems, to varying degrees depending on the internal circuit design and grounding scheme used in the units in question.

All of these problems (and the resulting degradation in sound quality that may result) are TOTALLY ELIMINATED when using BALANCED interconnections!!


No, that is incorrect. The National Electric Code virtually guarantees that your statement is wrong. NEC requires all AC fed equipment have a bonded safety ground which protects the user from energized metal, and the bonding mechanism must have sufficient conduction to clear the breaker within two line cycles (or half cycles, I'm typing from memory). This guarantees ground loops even with balanced connections (google pin 1 problems).

I've found no work to date on the elimination of the effect of chassis ground loop currents.

Cheers, John

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Re: some good links on cable discussion


Quote:
Various DIELECTRIC materials (teflon, PVC, etc.) certainly have an effect on the capacitance and inductance of a cable, but that is a separate issue.

For the vast majority of wire configurations, the permittivity of the dielectric has no effect on the inductance of the cable. The only case where this can be true is the case of extremely wide parallel flat ribbon cables, where the dielectric is very thin in comparison to the conductor width. In this case, the charging currents required to "fill" the dielectric is able to cause constriction of the current density profile, meaning the current will tend to concentrate in the center of the ribbon, shying away from the edges (Lenz effects, sometimes called proximity effects in the magnetics discipline). In this case, the characteristic impedance of the cable during the leading edge of a square wave would be slightly higher than the nominal impedance, and over time, the current profile will re-distribute such that the balance of the dielectric will charge. It must be noted that this effect is far more predominent within electrolytic capacitors when the two plates are connected at the extreme ends of the foil lengths, as the solenoidal field of the charging current will pinch the current and starve the dielectric...but I digress, this is a cable thread..


Quote:
In any case 98% of the discussion I see here is way way off of the mark if we are talking about the audible effects of interconnects in audio.


For me, it's more like 50%, but we are in general agreement.

Unfortunately, quite a bit of that 50% (for me) comes from the engineering community. (I note that even 1% is too much, I set the bar far higher when it comes to engineers, physicists, and scientists).

Cheers, John

SAS Audio
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Re: some good links on cable discussion

Thanks Elk for inviting me into the conversation. I only have a few comments, from actual tests I have performed myself. Please forgive me for mentioning some of my designs etc. as I am a manufacturer of Ics, amps, preamplifiers. So full disclosure.

The first point is that I have spent years with several types of interconnect cables I built myself. They both use the same wire, have basically the same inductance, capacitance, and resistance. I state "basically" because the different plugs used, Vampire all copper with gold plating vs Cardas rhodium plated (approx 1.9pf vs 2.2pf), solders used may have slightly different resistance values, different materials used etc. I measured the capacitance between the ICs and they were within approx 3pf out of 40pf total. Since capacitance is the dominating factor, I measured using a Tektronics capacitance meter. Output impedance (Z) of the preamp is approximately 2k ohms. Input Z of the amp is approx 100k ohms with approx 75pf input capacitance. As one can see, the high frequency response varies little with a 3pf change between ICs.

In my opinion, and it is just my opinion; what I found over the years of testing is that materials do make a sonic difference, although it takes a good system with good room acoustics, i.e. not bass heavy, to notice the changes.

As far as balanced vs unbalanced, I prefer unbalanced for several reasons.

1) Having tested various passive parts such as resistors and capacitors over the years, I noticed sonic differences. So some parts appear to me to be more accurate than other parts. However, I deem no part as perfect. I wish to limit the number of parts used.

With more parts in a balanced design vs an unbalanced design, more sonic degradation will occur because of more parts. So I had to determine which parameters are more important, external problems or internal. Being I live approx 5 miles from two 2,200,000 visual and over 200,000 aural watt transmitters and I have no apparent problems I elected to work on the internal problems.

2) Another problem besides part numbers is the extra power supply needed (unless splitting transformers are used to create balance. However I wish to limit the number of transformers.) Imo, power supplies are a real devil to get right. I use separate power supplies for each stage vs one large power supply for all stages, for a number of reasons. Two power supplies for two stages are bad enough, but three (a negative supply) are even worse.

As mentioned earlier, I prefer to take my time and do listening tests over a long time.

Take care.
Steve

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Re: some good links on cable discussion


Quote:
Since capacitance is the dominating factor....Steve

I have long pondered responding....alas, my emotions have gotten the best of me... (please bear with my overly long diatribe)

For IC's, capacitance is indeed the dominating factor. Because the impedance of a typical IC is far lower than the impedance of the load, capacitive storage will dominate the system. You speak well in this regard.

However....

Imagine a source component with two outputs, very low output impedance.
Connected to an amplifier with two inputs, both 10kohms.
Both are connected via 3 prong power cords to the wall outlet.
Specs:
IC ground, 50 milliohms each shield plus connection contact resistance of say, 10 milliohms...70 milliohms total.
PC ground, 5 milliohms plus 5 milliohms connection resistance, 10 milliohms total..(yes I play fast and loose with the actual numbers...it's the understanding that is key)

Now, one channel, left, a 10 volt DC signal.
Left inner conductor current is 1 milliamp.

What path does the return current take???
Left shield??? Not exactly.
Right shield"" Same answer...
PC ground? Yup, the bulk of the return current is through the PC ground. That is because it is the path of least resistance. For the numbers specified, the ratio of ground current to shield current is indeed.. 7 to 1. Meaning for dc, the ground current within the power cord is 7 times the shield return current of the IC.

Recall that for a shielded cable to be able to "shield", the return current on the shield MUST BE exactly the inner hot signal current.. But yet, it is not, is it?? So, why do we call it a shielded cable???

At DC, the current is everywhere. AND, at low frequencies, it is the same, At infinite frequencies, yes the shield will be a true shield......

And, there is nothing that can be done to prevent the ground loop from intercepting B dot ...time varying magnetic field, at the low frequencies. nothing..simply because you have NO control over where the currents go, you have no control over the ability of the "shield" to do it's job...and that is only the external system. I do not even broach the guts of the equipment...that is also a mess theoretically and in terms of understanding..but that gets complex, let's keep the discussion at a rudimentary level for now..The basic fact is, you have NO control over the signal current path, and you do not understand that you do not have control. This is the crux of the science of EMC...

At what frequency will the return current in the shield be half the signal current??? Simple. Just model it.
OOps, we need the inductance of the ground loop, we need the inductance of the two IC shields in their loop. Then we can calculate the break frequency for the IC's shield current..

Given the complete lack of control over the return current path, how can any real electrical engineer make the silly claim that IC's cannot make a difference? How can any electrical engineer make the silly claim that a power cord cannot make a difference??? Why do the electrical engineers ignore the ground currents and it's path?? Honestly, if anybody presented the equivalent of "IC's and PC's can't make a difference" at a conference I were in attendence of, I'd have to fight the inclination to give them...another orifice. A difficult battle I will admit.

All one has to do is model the path of the return current to see that single ended signal distribution is full of error sources. How in the name of sam hill can anybody claim that a switch box cannot cause a difference?? It alters everything!!!! Duh..

Modelled correctly, one can make the determination as to the level of effect the ground loops and field intercepts can have on the audio signals, then determine if it indeed acheives JND levels.

There are a few ways to counter these effects...but first, one must believe they exist. Faraday's law of induction is a start. Lenz is second.. IEEE 1050 is third. (just ignore the statement on page 16 which claims the speed of propagation of an e/m field in free space is 299 meters per second...apparently they lost 6 decimal places..in the ensuing 5 years, nobody has seen fit to correct such a silly error)...details, details...

Until these effects are understood....IC's and PC's will remain voodoo and magic.

They are not.

Welcome to EMC 101.

And I apologize for the rant. But honestly, I feel that it's time.

Cheers, John
ps..sasaudio, this was not directed at you..you have been wonderful. I would enjoy working with you on designs if you would be so inclined to PM me..
pps..I am finally finished with the edits...
ppps.. My belief is..my clarification of ground loop theory will accomplish nothing in the world of high end audio.

SAS Audio
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Re: some good links on cable discussion

Hi John,

Yes, I appreciate the accurate and enlightening information concerning ground/signal loops etc you have posted. And thanks for the return PM.

Most everything has already been covered in my designs concerning grounding loops (one small tweek needed, unsoldering a wire), but there is a minor tweek I will perform to help minimize even more the problem of channel to channel loops. I hope others, especially major manufacturers of CD players, Phono stages, tuners etc work on their loop problems, hope springs eternal

Take care and thanks again John.
Steve

Ps. Just finished testing the power supply integrities (loop problems) and could not find any abnormalities.

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