ΟΙ ΘΕΩΡΙΕΣ ΤΩΝ ΚΑΤΑΣΚΕΥΑΣΤΩΝ ΚΑΛΩΔΙΩΝ : Η Θεωρια της XLO

[LUXMAN]

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Παραθετω παρακατω τις "λευκες" σελιδες της κορυφαιας σειρας καλωδιων της XLO . Ειναι γραμμενη η φιλοσοφια της εταιρειας σχετικα με το πως θα επρεπε να κατασκευαζεται ενα καλωδιο ωστε να επηρεαζεται οσο το δυνατο λιγοτερο το μεταφερομενο σημα .
Οι αριθμοι που βλεπετε διασπαρτοι στο κειμενο ειναι παραπομπες και θα τις βρειτε στο τελος του τεταρτου των post αυτων .



White Paper: XLO Limited Edition cables

Introduction

Jonathon Scull's review of XLO's Limited Edition in the August, 1998 issue of Stereophile said that "...the Limited Edition was always and totally superb.", and went on to say that "...[the] Limited Edition is almost certainly the best cable that will ever be made." One month later, in the September, 1998 issue of Fi, The Magazine of Music and Sound, Michael Gindi reviewed the Limited Edition and enthused that "... [As it burned-in,] It just kept getting better and better and better, until it disappeared entirely, and nothing was left but the music." Dr. Gindi came back with more high praise for the Limited Edition in “Fi magazine” in February of 1999, and in the Spring of 2000, Myles Astor, after reviewing nine of the world’s best speaker cables in Ultimate Audio magazine, declared that “Compared to the XLO, other cables sounded muddy and distorted.”

Those reviews were just the beginning. For more than half a decade, since its introduction in 1998 until just now in 2003, the world’s leading audio reviewers have found XLO’s Limited Edition to be clearly and obviously “The Best in the World.” This paper will tell “how” and “why” that is.

XLO Advanced Technology

More important, perhaps, than any other one reason for the Limited Edition’s superiority is that the design for every XLO Limited Edition cable is based upon genuinely advanced technology, applied in a “total system” approach, to each specific cable application, always in accordance with XLO’s basic controlling philosophy that the cable should pass signal exactly as it receives it, with no addition, subtraction, coloration or distortion whatsoever.

One example of XLO’s advanced technology is found in its proprietary “Field Balanced” winding geometry. Put most simply, although many other cable manufacturers seem to recognize and design for the effects of ambient electromagnetic fields, and some even (but many don’t) allow for electromagnetic fields self-generated by internal current flow, XLO is still the only cable manufacturer in the world to recognize and design for the fact that ALL CABLES IN OPERATION GENERATE BOTH ELECTROMAGNETIC AND ELECTROSTATIC FIELDS WITHIN AND SURROUNDING THEM.

These internally generated fields (the intensity of the electromagnetic field controlled by current flow, and that of the electrostatic field controlled by voltage) both – individually and by their interaction – affect the signal passing through the cable, and therefore affect the sound of the entire system.

Because the signals passed in each different cable application all have different relative amounts of current flow (amperage) and of voltage1, but there is only one optimum relationship for the two fields that result from them, every XLO cable, in every series from XLO/Ultra all the way up to the Limited Edition, is specifically designed to produce that one optimum relationship in its own application. THE REASON WHY XLO CABLES ARE WOUND DIFFERENTLY AND LOOK DIFFERENT FROM EACH OTHER AND FROM EVERY OTHER BRAND OF CABLES IS SO THAT ALL WILL HAVE THE EXACT SAME OPTIMUM FIELD RELATIONSHIP, WHATEVER THEIR APPLICATION MIGHT BE. This is XLO’s exclusive “Field Balanced” technology, and it’s one of the reasons why XLO cables really are The Best in the World.

The reason for the Limited Edition’s incredible detail, focus and ambience retrieval lies in another example of XLO’s advanced technology: Functionally, cables (of any brand, even XLO) have many of the characteristics of capacitors: They store energy in their dielectric (on a cable, that means the insulation) and they release it OUT OF PHASE, DIRECTLY INTO THE SIGNAL PATH every time the carried signal changes polarity. This out-of-phase energy results in cancellation of the signal information at very low levels (like the fifth bounce of the music off the walls of the concert hall!), and works to reduce detail, blur imaging, and even result in “phantom” signal artifacts (“noise” signals that aren’t a part of the recording being played) to further spoil your listening enjoyment. XLO IS THE FIRST CABLE MANUFACTURER TO RECOGNIZE THIS VERY REAL PROBLEM, AND IS STILL THE ONLY ONE TO HAVE SUCCESSFULLY ADDRESSED IT 2.

 

[LUXMAN]

ΟΙ ΘΕΩΡΙΕΣ ΤΩΝ ΚΑΤΑΣΚΕΥΑΣΤΩΝ ΚΑΛΩΔΙΩΝ : Η Θεωρια της XLO μερος Β'

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Everything is Important

XLO’s “total system” approach to cable design is exactly what the term implies: Every aspect of every part of every XLO design is taken into consideration and optimized, not only in itself, but as it interrelates with all other aspects of the design before the design is finalized and sent to production.

Although there are cable manufacturers who seem to believe that there can be one “magic” solution that will always result in “perfect” cables3, the fact is that cables are not nearly as simple as they seem. Even though the casual observer may see them as just bits of wire and plastic, cables are actually extremely complex in their operation, and EVERYTHING about them affects their performance: The material used for the conductors (usually either copper or silver in most audio cables 4 ) has a clear and obvious effect on the sound of your system. So does the thickness (the AWG gauge) of the conductors, their purity, how they were made 5 , and whether they are solid-core or stranded. Dielectric and capacitive discharge effects mean that the choice of insulating material for the primary wires 6 , it’s dielectric constant 7 , its “dielectric absorption” or “dissipation factor 8 “ its “dump rate 9 ”, and how thickly it’s applied are all crucial. And these same considerations are all equally important to the kind and thickness of each of the overall conductor jackets, the filler materials, if any, and the final overjacket on the finished cable. The cable winding geometry is important. Whether or not the cable is shielded is important, too, because shielding – even shielding done the way XLO does it – can affect sound quality and overall system performance. And so can the spacing of the shield, if any, over the cable and the spacing of the conductors within it: Nothing more than the distance between them determines the capacitance and inductance of any pair of conductors, and those factors, plus the resistance of the conductors, themselves, are the sole determinants of the cable’s characteristic impedance. The ultimate importance of absolutely everything to good cable design is perhaps best shown by the fact that even as seemingly small a factor as whether or not its center core is perfectly round can significantly affect how closely a coaxial cable will come to meeting its designed impedance specifications.

In designing its cables, XLO takes every one of these things into consideration, and more. And that, finally, is the biggest difference between the Limited Edition and almost every other cable – even from XLO’s own other product lines. Every other product that we know of embodies compromises that must be made to comply with budgetary considerations, the vagaries of the market, or the realities of manufacturing. Even if the manufacturers know what should be done to make for truly outstanding performance, they’re limited by what can be done within the budget they have available, the price they think they their customers might be willing to pay, or the machines and processes they have available to them for manufacturing.

The Limited Edition is different. Absolutely uncompromised in any way, and representing the fullest development of the thoughts and skills of designer Roger Skoff, the Limited Edition is, even as compared to XLO's justly world-famous Signature Series and UnLimited Edition, a huge step forward. Barring radical improvements in materials technology or major scientific breakthroughs, it is almost certainly, just as Jonathon Scull wrote: “...the best cable that will ever be made.”

The Limited Edition Product Line

The Limited Edition consists of only six products: LE-1, The Unbalanced Interconnect, LE-2, The Balanced Interconnect, LE-4, The Digital Interconnect, (available either balanced or unbalanced), LE-5, The Speaker Cable, (along with its companion product the LE-5js Jumper Set)and LE-10, The Power Cord. No other model names have been assigned or are necessary -- The Limited Edition cables are the best XLO knows how to build, and just their performance is all it takes to set them apart from any competitor.

 

[LUXMAN]

ΟΙ ΘΕΩΡΙΕΣ ΤΩΝ ΚΑΤΑΣΚΕΥΑΣΤΩΝ ΚΑΛΩΔΙΩΝ : Η θεωρια της XLO μερος Γ'

Materials and Construction

Limited Edition Interconnects

All XLO Limited Edition interconnecting and digital cables are made from custom-drawn and specially treated “Laboratory Grade Plus“ copper, which is so pure that it actually exceeds the test capabilities of any U.S. commercial laboratory. Conductors of this rare and expensive material are individually insulated with thin films of a special DuPont™ Teflon™-related fluoropolymer material and then arrayed in XLO's own proprietary "Field-Balanced" geometry between an air- and nitrogen-bearing concentric two element fluoropolymer central core and a single element air-bearing fluoropolymer outer core analogue. The insulation and core structure thus formed has a lower effective dielectric constant than any other kind or combination of commercially available materials and has a mean audio frequencies dielectric absorption factor significantly lower than even DuPont's own Teflon AFTM -- an ultra-premium licensed product for special military and aerospace applications that sells for more than US$ 7.00 per gram! Where necessary for balanced or AES/EBU operation, a special grounding network is incorporated within the central core.

The outer "skin" on all Limited Edition Interconnects and digital cables is woven from multiple custom-extruded air-bearing tubes of Teflon-related material in a special "cross-one" pattern, which can only be done on specially adapted machinery. The result is outstanding electrical, dielectric, and field characteristics, with a degree of flexibility never before achieved in any large diameter high performance cable.

All connectors used on Limited Edition interconnects and digital cables are of XLO’s own design and built to XLO’s own high standards. Every connector is non-magnetic, to avoid hysteresis effects, and each is designed for minimum self-inductance. Every part in the signal path of every Limited Edition connector is precision manufactured from either Laboratory Grade ultra-pure copper or from an ASTM-designated copper alloy selected to be best for its particular application. RCA connector contact pins, for example, and those of XLO’s proprietary male XLR connectors are machined from solid billets of Tellurium copper, while the pin receptacles of female XLR connectors are formed from special Brush-Wellman Alloy 174 Beryllium copper. Where gold plating is used, it is applied directly, with NO nickel substrate, just thickly enough to prevent connector tarnishing, WITHOUT affecting sound quality10 . To ensure minimum self-inductance, steps are taken on every Limited Edition connector to remove all conductive materials not absolutely necessary to signal transmission from the signal path. The dielectrics of all XLO Limited Edition XLR connectors are made of a special General Electric engineering grade thermoplastic polyester resin. All other Limited Edition connectors which employ dielectric materials use DuPont Teflon.

All interconnects are unshielded, and do not require shielding in most applications. Special external shielding may, if necessary because of unusually high-noise environments, be ordered at additional cost. Where shielding is specified, it is of XLO’s own free-floating “Faraday Cage” design, with gold-plated grounding clips at both ends.

Speaker cables

XLO Limited Edition speaker cables are made from the same specially treated ultra-pure (exceeding U.S. commercial lab test capabilities) "Laboratory Grade Plus" copper as is used for Limited Edition interconnects and digital cables. Multiple small-diameter conductors (23AWG) of this material are individually insulated with thin films (0.076 mm or less) of a special DuPont™ Teflon™-variant fluoropolymer material and served, in accordance with XLO’s proprietary “Field-Balanced” geometry, over air-bearing composite multi-element concentric Teflon-variant core structures to make the cable’s four individual conductor “legs”. Each of these four legs is then wrapped and extruded with a twin-element Teflon-variant fluoropolymer jacket and the four legs are cabled, either around an air-bearing central core member or a special internal shielding network (depending on whether the cable is for unbalanced or balanced amplifier operation), into a minimum-inductance "quad", and finally given a braided Teflon mesh outer jacket.

Limited Edition speaker cables are two conductors of 6 gauge (AWG) in their normal "shotgun" configuration (2 legs per conductor) or four conductors of 9 AWG when terminated in the optional "bi-wire" mode. Regardless of configuration, all Limited Edition speaker cables feature individually machined gold-anodized "end caps" with two-part epoxy brand and directional markings and laser-etched serial numbers. Protruding through these caps at either end are the actual hook-up ends of the cable. These are sheathed in multi-element air-dielectric tubes woven from custom-extruded Teflon-variant materials, colored in purple or a pale lavender shade to match the leg color of the conductors for which they provide termination. The actual termination is, in every case, an individually billet-machined Laboratory Grade copper spade lug (of either 6 or 8 millimeter terminal size) covered in a separately machined anodized aluminum shell. Only spade terminations are offered, as these are the only termination type XLO believes to be of sufficient quality to match the cables.

 

[LUXMAN]

ΟΙ ΘΕΩΡΙΕΣ ΤΩΝ ΚΑΤΑΣΚΕΥΑΣΤΩΝ ΚΑΛΩΔΙΩΝ : Η ΘΕΩΡΙΑ ΤΗΣ Xlo ΜΕΡΟΣ Δ'

Specific Product Descriptions

LE-1 The Unbalanced Interconnect -- Much larger in diameter than would normally be expected from XLO, this Limited Edition cable features unique jacketing braided from ultra thin-wall air-filled Teflon tubing. This results in truly remarkable dielectric characteristics and an appearance and texture reminiscent of snake skin. Highly polished low self-inductance connectors of XLO's own design complete the impression of luxurious high quality, while fully symmetrical windings and special geometry make this unshielded unbalanced cable unusually resistant to EMI and RFI.

LE-2 The Balanced Interconnect -- Similar in construction and jacketing to The Unbalanced Interconnect, this unshielded cable relies upon the Common Mode Rejection inherent to balanced ("differential mode") operation to provide outstanding sonics without the need for shielding. Special Limited Edition XLR connectors are custom machined and precision die-cast, with pins (male) and pin receptacles (female) of billet-cut Tellurium copper or patented Brush-Wellman Alloy 174 beryllium copper as standard.

LE-4 The Digital Interconnect -- Designed for quick rise-time, broad bandwidth, and the lowest available cable-induced jitter of any product currently available, this Limited Edition cable has been adopted as an absolute reference standard by manufacturers of some of the most technically advanced digital equipment in the world and is the cable of choice for many of the world’s most critical and demanding audio reviewers. LE-4 cables are available either unbalanced, with RCA or BNC connectors, or in balanced configuration with XLR connectors, for AES/EBU.

LE-5 The Speaker Cable -- Six AWG; Quad multi-core construction; ready for either "shotgun" or "internal bi-wire” application11; billet-cut direct gold-plated Laboratory Grade copper fittings, phenomenal dynamics, and sound quality that puts all others to shame make this the speaker cable of choice for systems that really do strive to duplicate the reality of the musical experience. Unquestionably and by far "the Best in the World", the LE-5 is also available in a model (LE-5B) specifically designed for balanced output amplifiers. This model features a special internal shielding network that, when used with balanced output amplifiers, acts like more than twenty interlocking coils, to trap current-induced noise between the “Hot” and “Cold” legs of the circuit and dump it to chassis ground. The result can be an improvement in signal-to-noise ratio12 of as much as 12dB, and the improvement in sonics and detail resolution can be simply amazing! (Note: LE-5B’s special construction functions by taking advantage of the fact that a balanced circuit has no true ground, but that, instead, each of the two amplifier output terminals acts as “ground” for the other. This is not the case with conventional (unbalanced output) amplifiers, which DO have a true ground, and will therefore derive no benefit from LE-5B’s special construction.)

LE-10 The Power Cord --This is the ultimate premium version of the spectacular new power cord that’s getting rave reviews from audiophiles and reviewers everywhere. Sharing an entirely new approach to power transmission technology with XLO’s Signature 2 Type S2/10 AC cord and the phenomenal UnLimited Edition UE-10, it’s an all hand-made 9+ equivalent gauge (AWG), multi-conductor, Teflon-dielectric, Teflon-jacketed masterpiece that will clearly and obviously outperform any other AC power cord now or ever likely to be made. Amazing high frequency detail, sweetness and extension, coupled with greater image width, depth and focus, plus utterly astounding bass “weight”, power and “slam” make this new power cable a required addition to any High-End system seriously intended to challenge the state of the art. And because they also make a clearly visible improvement to the performance of any Video Projector or other video electronics device, XLO highly recommends LE-10 power cords for any video application calling for state-of-the-art performance. LE-10 AC power cords are jacketed in specially-woven XLO Purple Teflon braid with black and purple trim, gold markings and a precision machined anodized and individually laser-engraved serial number block. Each is fitted with custom-made ultra-premium gold-plated U.S.-style plugs (NEMA males are Audio Grade), and delivered in its own laser-engraved wood presentation case. European-style or 20 Amp connectors are also available at slight additional cost. Because of this cable’s genuinely radical design and construction, UL listing, which is currently being sought, may not be available. XLO certifies, however, that all connectors used on LE-10 power cords are UL approved, and that the cables, themselves, will exceed all performance and fire safety standards known to XLO by no less than 100 percent and, depending on the specific standard and the specific performance or safety characteristic, may exceed it by as much as THIRTY TIMES!
ΠΑΡΑΠΟΜΠΕΣ
1 The signal passed by phono cables is tiny fractions (thousandths or fractional thousandths) of an Ampere of current at equally tiny fractions of a Volt. The signal carried by an unbalanced interconnect in a high impedance circuit is just millionths of an Amp at as much as 10 Volts; that of a balanced interconnect or digital cable in a matched-impedance circuit is milliamps (thousandths of an Amp) at, again, as much as 10 Volts; and that of a speaker cable may be as much as 50 or 60 Amps of current at as little (typically) as just a few thousandths of a Volt.
2 Interestingly, when capacitive discharge effects in cables were first made public by Roger Skoff, XLO’s founder and Chief Designer, in a Stereophile interview with Jonathon Scull, the internet chat lines were for some time after clogged with audiophiles and other cable manufacturers denying that such a thing could ever be possible. Even more interestingly, within two months after the appearance of the interview, a number of the manufacturers were, themselves, talking about capacitive discharge effects, although usually with some different (and often “proprietary”) name.
3 You know who these are: Siltech seems to believe that the only thing important about a cable is what metal it’s made of; MIT and Transparent put all of their faith in “magic boxes”; Nordost and others seem to think that geometry is the be-all and end-all of cable design; and so on...
4silver-plated copper has also been used, as has MU-metal (a specialty product originally developed for electromagnetic shielding), aluminum, copper-plated steel and even – possibly on the theory that if it costs more it must be better – so has gold!
5Wires can be rolled, drawn, cast, continuously cast, or slit from sheets or foil.
6The primary wires are the individual conductors from which the major conductors are made. Primary wires may be either solid or stranded, but are always used in groups to form a single current-bearing conductor.
7Any non-conducting material may be used as a dielectric, and, if placed between two active conductors, will store energy for as long as the flow of current in the conductors remains of the same polarity. The amount of energy that will be stored by any cubic volume of a material as compared to the same volume of hard vacuum is the dielectric constant of that material. As an example, PVC with a particular kind and amount of softeners used in its manufacture may store six times as much energy as would the same volume of hard vacuum. That being the case, it would be said to have a dielectric constant of six. By comparison, Teflon, one of XLO’s preferred dielectrics, has a dielectric constant of just two.
8Of the amount of energy stored in any dielectric material, some portion will be lost as heat and the rest will be dumped back into the signal path when the polarity of the signal changes. The dumped energy is the source of capacitive discharge effects and the other amount, that which is lost to absorption or dissipation is the “dissipation factor.” If the dissipation factor were 100%, there would be no capacitive discharge effects, but, lacking functioning capacitors, there would also be no electronics and no need for cables, either.
9 A dielectric material’s dump rate is the rate at which it is able to discharge its stored energy in preparation for recharge with energy of the opposite polarity. The higher (faster) the dump rate, the less capacitive discharge energy will affect the transmitted signal energy and the better the cables will sound.
10 Perhaps surprisingly, gold is neither particularly good-sounding nor a particularly good conductor. It’s only about 40% as conductive as copper and is extremely self-inductive at very high frequencies. For these and other reasons, most well-designed connectors use gold ONLY for cosmetic purposes or to prevent contact corrosion.
11 Or use LE-5js jumper cables as an alternative to bi-wiring when using bi-wireable speakers. LE-5js jumpers are made from exactly the same conductors and dielectric materials as the LE-5 speaker cables and match their performance perfectly.
12 relative to actual signal level

 

[LUXMAN]

....και λιγη ιστορια της Xlo

COMPANY HISTORY

XLO Electric is a young company that has very rapidly come to the forefront of its field. Since 1991, when the company was founded, XLO’s products have gained enthusiastic acceptance by Audiophiles around the world and been the subject of an ongoing series of rave reviews in the world audio press. XLO Electric Company has been nominated for DuPont’s prestigious Plunkett Award for Technical Excellence and the Golden Note Award of the Academy for the Advance of High End Audio.

XLO was started by Roger Skoff, who, like a number of other High-End luminaries (Conrad and Johnson, for example), is an economist by training. He was educated at UCLA; has been Director of Business Analysis for four divisions of International Industries, Inc., and has consulted to various companies, including a number listed on the Fortune 500.

Since the age of twelve Mr. Skoff has had an active and growing interest in sound and its transmission and reproduction. Besides a life-long commitment to the very finest in High Fidelity sound, he has, in addition to his regular professional career, worked as a recording engineer, a radio announcer, an audio equipment reviewer for Sounds Like… magazine, and as Editor of Sounds Like…News.

Mr. Skoff’s active involvement in the design of high-performance audio cables began as a recreational math exercise in late 1986. This rapidly passed from a purely abstract theoretical study to the stage of concrete experimentation, and by 1988 the first of his cable designs; now known as XLO Electric™ Type 1, was completed.

Other designs followed, and by the time he started reviewing, most of the cables now comprising the XLO Electric Reference Series had been built and were incorporated into his Reference System for evaluating the performance of other High-End audio components. Because of the strict ethical requirements of reviewing, however, and because Mr. Skoff had no intention whatsoever of offering his cables for sale, the cables were identified in his system only with a misleading “codename”; they were never written about; and their source was kept a strict secret, even to most other reviewers.

Some reviewers though, close friends of Mr. Skoff, not only knew the cables’ source, but were even given some for use in their own reference systems. From this use, the word spread that a new “mystery cable” – of unknown origin, and not available at any price – was on the scene, and it quickly became the talk of audiophiles across the United States.
When the truth leaked out, in November of 1990, at a meeting of the Audiophile Society in Westchester County, New York, Mr. Skoff received, within just a few weeks, nearly a hundred phone calls from enthusiastic audiophiles wanting to buy his cables.

The rest is history: In December, 1990, he took a leave-of-absence from the magazine, to prepare sample cables for trial introduction at the Winter Consumer Electronics Show of January, 1991. The response at the Show was immediate and overwhelming: Dealers in the United States and Distributors abroad WANTED the cables. The result was that Mr. Skoff’s departure from the editorial field became permanent and in March of 1991, XLO Electric Co., Inc. was formed.

 

[LUXMAN]

ΟΙ ΘΕΩΡΙΕΣ ΤΩΝ ΚΑΤΑΣΚΕΥΑΣΤΩΝ ΚΑΛΩΔΙΩΝ : Η ΘΕΩΡΙΑ ΤΗΣ XLO για τα Balanced Speaker Cables ΜΕΡΟΣ 1

White Paper: Balanced Speaker Cables

One of the most exciting new developments from XLO is the Balanced Speaker Cable Option. This is available at no extra cost on both of XLO’s top-of-the-line speaker cables; the super high-performance UnLimited Edition (model UE-5B) and the Limited Edition Speaker Cable, recognized everywhere as being simply “The Best in the World”.

Balanced speaker cables represent an important new breakthrough in speaker cable technology and can provide their user with important sonic benefits 1 . This is possible, though, only when they are used in conjunction with “balanced” or “differential” output amplifiers. To understand why this is so, let’s take a look at how both balanced and unbalanced circuits work.

The first thing we need to understand in considering an electrical circuit of any kind is that it MUST, in fact, be a “circuit”. It must provide a pathway for electrons to flow from areas having surplus electrons (a “positive” charge 2 ) toward areas with too few electrons (a “negative” charge) and back. If there is nowhere for surplus electrons to go to, or (in the case of a “negative” current flow) for lacking electrons to be supplied from, we say that the circuit is not “grounded”. Breaking the circuit, by, for example, throwing a switch, creates an “open” (ungrounded) condition, and the opposite, allowing electrons to go to ground before they’re supposed to, is a “short” circuit. Grounding is the key to everything, because without a “ground”, no current can flow, and the way in which they form their grounds is the most important difference between balanced and unbalanced circuits.
In an unbalanced circuit (let’s use a conventional amplifier as an example) there is one terminal (usually color-coded RED) that is described as “hot”. This terminal is
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1 including an improvement in signal-to-noise ratio (relative to signal level) of as much as 12 dB and corresponding improvements in low-level intelligibility, ambience retrieval and detail resolution.
2 Actually all electrons have a negative electrical charge, so a locus having a surplus of electrons (MORE than normal) should really be described as being negatively charged. Because electrons flow, however, from areas where there are too many to areas where there are too few, the convention has become to speak in terms of electron count instead of electron charge, and we say that an area with surplus electrons is “positive” (the RED terminal of an amplifier, for example, is regarded as nominally positive) and one with a shortage of electrons is “negative” (the amplifier’s BLACK or “ground” terminal is regarded as nominally negative).

 

[LUXMAN]

ΟΙ ΘΕΩΡΙΕΣ ΤΩΝ ΚΑΤΑΣΚΕΥΑΣΤΩΝ ΚΑΛΩΔΙΩΝ : Η ΘΕΩΡΙΑ ΤΗΣ XLO για τα Balanced Speaker Cables ΜΕΡΟΣ 2

usually considered to be the source of surplus electrons which flow from the amplifier, through the speaker cable, to the loudspeaker, then through the loudspeaker’s crossover network and drivers, back to ground at the amplifier’s (usually color-coded BLACK) other terminal. In such a circuit, the only terminal that is powered (“Hot”, because it’s actually driven by the electronics) is the RED one. Electrons may, if required, flow back to the red terminal from the black one, but if they do, such a flow is always in response to and initiated by the state of charge of the red terminal. The black terminal of an unbalanced circuit NEVER initiates current flow. The proof of this is simple: [Important Note: NEVER DO THIS AT HOME! It COULD destroy your amplifier, and, at the very least, will blow all of its fuses!] Running a lead from the amplifier’s red terminal to an earth ground – a cold water pipe, for example -- will produce a flow of current and maybe even some sparking; doing the same thing with a lead from the amplifier’s black terminal will produce no current at all.

Balanced (differential) amplifiers are different. Instead of having one HOT and one GROUND terminal, they have TWO “hot” terminals (actually one “HOT” and one “COLD”, 180 degrees out of phase with each other). Both of these terminals are powered by the electronics, and, regardless of what color coding may be employed, the amplifiers have no conventional “ground” terminal at all.

The way balanced amplifiers work is really very simple: As the music signal (which appears at the amplifiers’ output terminals as an alternating current), varies constantly in polarity, from positive to negative and back again, each of the two output terminals also changes polarity. Neither of the terminals is consistently either positive or negative in charge, but both change with the polarity of the signal. Because they are out of phase with each other, this means that whatever the polarity of either terminal is at any given instant, the polarity of the other will be the opposite, and, if a wire is hooked-up across them, current will flow from whichever terminal is positive at that instant to whichever is negative.

In this configuration, each terminal acts as “ground” for the other and there is no “true” ground for the circuit. Instead, we say that the circuit is isolated from, or “floats above” ground, and it is this unique grounding architecture that XLO takes advantage of for its Balanced Option speaker cables.

Remember that every time current flows through a conductor (as, for example, signal current flowing through a speaker cable) an electromagnetic field is formed around that conductor of an intensity determined by the strength (amperage) of the current flow and in a direction consistent with the “Right Hand Rule” 3 . Remember, also, that

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3 The Right Hand Rule says that if you wrap your hand around a (insulated) wire in such manner that your thumb is extended and pointing in the direction of the current flow, your curled fingers will indicate the direction of the resultant electromagnetic field.

 

[LUXMAN]

ΟΙ ΘΕΩΡΙΕΣ ΤΩΝ ΚΑΤΑΣΚΕΥΑΣΤΩΝ ΚΑΛΩΔΙΩΝ : Η ΘΕΩΡΙΑ ΤΗΣ XLO για τα Balanced Speaker Cables ΜΕΡΟΣ 3

that electromagnetic field will collapse (and re-form) every time the (AC) music signal changes polarity, and that the collapse of that field will induce a current flow in every GROUNDED 4 wire within it. 5 In the case of speaker cables, because there are two conductor “legs”; because both legs are effectively grounded by the amplifier; and because each leg is within both its own electromagnetic field and that of the other leg, there will always be both “mutual” (the collapse of the field around leg “A” induces current flow in leg “B”) and “self” inductance (the collapse of the field around leg “A” induces current flow in leg “A”), and unintended extra induced current flows will always be generated within the cable and added to the musical signal from the amplifier.

These extra current flows may, depending on the specifics of the circuit, be either in phase with the music signal or out of phase. In either case, they constitute additional electromagnetic noise which reduces the total effective signal to noise ratio and masks, blurs or actually cancels out low level detail and ambience retrieval.

The way to get rid of electronic noise is by using shielding. This can be thought of as being analogous to a lightning rod: Just as mounting a lightning rod to its roof will cause lightning to be diverted from striking your house and harmlessly channel it to ground, so the use of electromagnetic shielding diverts spurious and damaging current flows from being induced in cables and other electronic equipment and instead routes them directly to ground. The way it works is simple: Putting a layer of shielding between the collapsing field of a noise source and the cable or electronics to be protected causes current flow to be induced in the shield instead of in the protected circuit. As long as the induced current can be dissipated to ground, the shield will function and the reduction of noise in the protected circuit will be proportional to the amount of dissipated current.

For noise generated outside of an unbalanced circuit, shielding is easy, and in interconnect cables, for example, the shield may even 6 be the “ground” lead woven around the outside of the “hot” conductor of a coaxial cable. For balanced interconnects, it’s even easier, noise arising outside the circuit is simply canceled-out as a result of “Common Mode Rejection”. 7

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4 Remember that unless there is a functional ground or ground-equivalent, there can be no current flow.
5 This induced current flow is the basis for the operation of electrical generators, alternators and transformers. It’s also both the reason for and the operating principal behind shielding against RFI and EMI.
6 but never in any XLO Electric brand cable .

7 Noise from a source external to the cable is induced equally in both the “hot” and “cold” legs of the cable. Because the two legs are always out of phase with each other, when the signal is summed, the identical out of phase elements cancel.

 

[LUXMAN]

ΟΙ ΘΕΩΡΙΕΣ ΤΩΝ ΚΑΤΑΣΚΕΥΑΣΤΩΝ ΚΑΛΩΔΙΩΝ : Η ΘΕΩΡΙΑ ΤΗΣ XLO για τα Balanced Speaker Cables ΜΕΡΟΣ 4

Shielding can’t protect against self-induced current flows, however, nor can it work where there is no ground for induced currents to dissipate to. That means, among other things, that shielding speaker cables to ground on an UNBALANCED circuit amplifier can be of NO BENEFIT AT ALL. The cables are already grounded, so no amount of additional grounding can help.

Balanced circuit amplifiers are a different thing, entirely. Because they have no actual circuit ground (remember that a balanced signal “floats” above ground) it becomes possible to shield the legs against mutually-induced current flows and to dissipate the induced currents to a completely isolated chassis or “true earth”ground!

That’s why XLO Balanced Option includes a special separate ground lead with solid copper “Crocodile Clip” connection. It’s for attachment NOT to either of the speaker terminals (OF A BALANCED OUTPUT AMPLIFIER, ONLY), but to one of the chassis mounting screws or any other grounded point on the chassis or elsewhere.

Shielding against mutually-induced noise can significantly improve the signal-to-noise ratio within the amplifier/speaker circuit. Because the noise levels being reduced are generated by the music signal, itself, the improvement will always be stated in decibels (dB) relative to the actual signal level being passed at any given moment, rather than against the amplifier’s arbitrary “full output” level, as would more normally be the case. To give you an idea of just how significant this is, although the ideal condition would of course be their total elimination, if both the voltage and the amperage of mutually induced electromagnetic noise can each be reduced by just seventy-five percent (75%),
the total effect would be an improvement of 12dB relative to signal level.

Listen for yourself. We think you’ll find the improvement in clarity, detail and ambience to be truly exciting and an improvement to your system.

 

[LUXMAN]

Why use copper? Why not silver?

There's only one reason why XLO's cables use copper instead of silver conductors:
copper sounds better 1 ! Silver has slightly less dc resistance than copper, so some
audiophiles believe that it ought to be better sounding. Unfortunately, that just
isn't the case: Music signals are always AC, not DC, and, as any physics text will
show, silver's greater self-inductance causes silver conductors to have a much
sharper ac resistivity gradient between their center and their surface than do
copper conductors of the same size. This means that any silver conductor of any
size and any length will always have more "skin effect phase shift" than any
identical conductor made of copper. Skin-effect phase shift is one of the things that
give silver cables that distinctive "shiny", "silvery" sound that many people seem to like.
XLO believes that cables should have no sound of their own at all, so we've never used
silver in anything other than our very least expensive cables 2 .

----------------------------------------------------------------------------------------------

1 It's certainly not because it's cheaper or easier to get. As of this date (November,
2001), Laboratory Grade copper costs over 3 times MORE than silver, and takes
more than half a year between time of order and final delivery.

2 A single silver strand was used at the center of the multi-metallic strand set
in the now-discontinued XLO/VDO ER-15 and ER-16 speaker cables.

 

[LUXMAN]

What is XLO's "field balanced" geometry and what's so good about it?

Whenever current is passed through a wire, an electromagnetic field is formed around
the conductor. When the current-carrying wire is insulated, an electrostatic field is also
formed around the insulation. Both of these fields – the current-controlled electromagnetic
field and the voltage-controlled electrostatic field affect the passage of
signal information, and can have a significant effect on the sound of an audio cable.
Many cable designers have tried to deal with one or the other of these field phenomena
(usually the electromagnetic field), but until XLO, no one had ever recognized the
importance of both fields and of their interrelationship. The fact of it is that there is
only one optimum relationship for the two fields, and where that is present signal
transmission is materially improved. Optimizing the relationship of the electrostatic
and electromagnetic fields is what XLO's "field balanced" geometry is all about.
It's also why XLO cables look different from everything else and even from each
other. This is understandable if you consider that different applications have
different current-to-voltage ratios, and that voltage and current control the intensity
of the different fields. Phono cables pass very tiny currents at equally tiny voltages;
line-level cables pass relatively very large voltages with very little current flow; and
speaker cables need to be able to pass very large currents at relatively small
voltages. With different current/voltage ratios creating different relative field
intensities, but only a single optimum field relationship, it's obvious that
different constructions will be necessary to achieve the same point of balance, and
that is exactly what XLO has produced.
XLO's High-End cables are the first to effectively deal with the physics of signal
transmission. That's why they seem to sound so good. The fact, though, is that they
have very little "sound" of their own at all – what XLO users actually hear and enjoy
is the sound of the music!

 

[LUXMAN]

Dielectrics? What are they and what difference do they make?

First let's ask a different question: Do you know what a capacitor is? Sure you do: It's
an energy storage device that's formed when any two electrical conductors (the "plates")
are separated by any non-conductor (the "dielectric"). "Charging" the capacitor is done
by passing current (of either positive or negative polarity) through the conductors. This
results in some of the (signal) energy being picked up and stored in the dielectric andthen dumped back (INTO THE SIGNAL PATH!) when the polarity of the current changes.
In a cable, the dielectric is the insulating material surrounding and separating the
conductors, and just like the dielectric in a capacitor, it will pick up some of the signal
energy passed through the cable and dump it back into the signal path (ALWAYS OUT
OF PHASE) when the signal polarity changes. This storage and subsequent dumping of
signal energy changes the signal, and therefore the sound of the entire system.
Poor quality or poorly chosen cable dielectrics are often the reason why cables have
a distinct "sonic signature" when, really, they should have no sound of their own at
all! For minimum sonic effect, the dielectric in a cable must store as little energy
as possible, (it must have a low "dielectric constant.") and it must return its stored
energy to the system in the smallest possible increment of time. (It must have a high
"dump rate.") DuPont Teflon has the lowest dielectric constant and the quickest dump
rate of any wire insulation material now available, and it or Teflon variants 1 are the
only dielectric materials that XLO uses in any XLO/Ultra, Reference2, Signature2,
UnLimited Edition or Limited Edition cable.
The ethylene polymers and co-polymers used in XLO/VDO (including proprietary
products like ,Elvax, Surlyn and Alathon) are the next best thing to Teflon. These,
while much less expensive than Teflon, also have excellent dielectric properties
and can offer outstanding cable performance. The lowest performance dielectric
materials are PVC compounds, thermoplastic rubbers and nylon. These are cheap,
easy to use, and tend to have a nice texture or "feel". While many other manufacturers
(including some "High-End" brands) make extensive use of these materials,
XLO will only use PVC for outer jacketing on its lowest cost cables, and uses none
of the others for any purpose at all.

-----------------------------------------------------------------------------------------------

1 Other DuPont Teflon-variant materials are even better, but these are not
available for commercial sale. XLO Electric Co., Inc. was nominated for DuPont's
coveted Plunkett Award for the innovative use of Teflon (Plunkett was the
DuPont chemical engineer who first developed Teflon), and has a special
relationship with DuPont that allows it to access DuPont "test batch" noncommercial
fluoro carbon materials. There are now twenty-six of these very
special products, of which four have been utilized in XLO Signature Series,
UnLimited Edition and Limited Edition cables.

 

[LUXMAN]

TPC from XLO - Contact Enhancer

TPC from XLO - Contact Enhancer

TPC is a non-cosmetic contact enhancer that chemically
neutralizes electrical contact oxidation and prevents
further oxidation or corrosion. It is NOT a metal polish, and contacts treated with
TPC may not show any visible change (i.e. contacts that look oxidized before
treatment may still look oxidized after treatment). What they WILL do is sound
better and perform better.TPC passes through the microscopic porosities present in any plated surface,
to reach and chemically treat the underlying base metal. This means better
performance for all electrical connections, whether contacts are plain (unplated),
tinned, or plated with nickel, gold, silver or any other material – even rhodium!

Besides eliminating the effects of oxidation, TPC's "soaking" action fills
microscopic pores and "hills and valleys" in the contact surface, to increase
available contact area and reduce resistance. TPC also reduces "contact rectification",
which can result in significant loss of low-level information. TPC immediately
improves the sound of any system. And there's even more
improvement after three to four hours – clear proof that TPC really does
soak in and do as it claims.

TPC makes things sound better, work better, and last longer. In Stereophile, Senior
Editor, Jonathan Scull raved that "One ninety-nine cent packet of TPC can make more
improvement to your system than an additional THOUSAND DOLLARS spent on
components." Fi (the magazine of music and sound), loved it too, as did reviewers
at Home Theater, The Stereophile Guide to Home Theater, and Audio Video Interiors,
who have tried TPC in their own systems and, without exception, all been amazed,
excited, and enthusiastic in their praise.

 

[RDoherty]

Πολύ ενδιαφέροντα όλα αυτά ... για τον εγχώριο αντιπρόσωπο της XLO.

 

[LUXMAN]

Ο οποιος ειναι ο υποφαινομενος !

 

[RDoherty]

Το είχα υποθέσει.

 

[Γιώργος(MAC)Αναμουρλίδης]

Το είχα υποθέσει.

Δεν είναι,ούτε ήταν ποτέ μυστικό. :|
Ο Μαρίνος,ο οποίος εργάζεται στο κατάστημα "Κοσμας",είναι ο αντιπρόσωπος των εν λόγω καλωδίων.

 

[Γιώργος(MAC)Αναμουρλίδης]

Luxman,(Μαρίνο),καλό θα ήταν προς αποφυγεί παρερμηνειών,να φτιάξεις κάτι αντίστοιχο που είχες σαν υπογραφή σε άλλο forum.

 

[Tidal_]

θα ηθελα να πω οτι εγω προσωπικα ζητησα απο τον LUXMAN να ανεβασει παλι το συγκεκριμενο thread απλα προς ενημερωση....
ο ιδιος δεν ηθελε για να μην παρεξηγηθει και μετα απο δικη μου επιμονη δεχτηκε...μην τρελενεστε...... 8)

 

[RDoherty]

Δεν ξέρω - και ούτε υποχρεούμαι να ξέρω - τι είναι μυστικό και τι όχι. Ούτε θεωρώ κατ' ανάγκην αντιδεοντολογικό να διαφημίζεται ένας αντιπρόσωπος/έμπορος/μαγαζάτορας/κλπ όσο εύσχημα (ή άσχημα) προκρίνει ο ίδιος. Επειδή όμως αυτά τα copy-paste σεντόνια με ενοχλούν prima facie, θα ήθελα να βλέπω στο τέλος παρόμοιων μηνυμάτων ένα disclaimer που να εξηγεί ποιά είναι η σχέση οικονομικού συμφέροντος του γράφοντος ως προς το περιεχόμενο του μηνύματος.