Moderator: Redaktörer
av dimitri » 2003-10-16 21:06
av Ranefjord » 2003-10-16 21:17
av Meridian » 2003-10-16 22:03
) och Bryston Elektronik. No subs to apply... 
Och till det en Stewart Firehawk, Yamaha DPX-1000 eller Barco Cine-9.
av Thomas_A » 2003-10-16 23:49
av Maarten » 2003-10-17 09:56
)). Men frågan om vad återgivning är för något, är en annan fråga som bör tas upp i en anna tråd, tycker jag.
av IngOehman » 2003-10-17 10:11
En model för skärpning och försoning:
1: Låt oss anta att Rydberg har rätt. Vilka argument talar för det?
2: låt oss anta att IÖ har rätt. Vilka argument talar för det?
Nu kommer det fina:
IÖ och likasinnade tänker ut alla argument för Rydberg &co
Rydberg och likasinnade tänker ut alla argument för IÖ &co
Det skall gäras uppriktigt och ärligt.
) inte ens tänker tanken att felet faktiskt kan ligga någon annanstans än i kabeln.
Så då skall jag försöka göra det, fast det är väl här som jag får problem...
.
av IngOehman » 2003-10-17 10:22
av Rydberg » 2003-10-17 10:53
Kloka ord!De har ju bara förmedlat sina upplevelser och dessa kan ingen ifrågasätta, varken jag eller någon annan. Jag har därför inte ens försökt ifrågasätta dem. Varför skulle jag göra det? Jag är övertygad om att de båda är ärliga människor, så det är klart att de upplevelser de förmedlar är sanna.
av IngOehman » 2003-10-17 12:52
, utan beror på omvända missanpassningsvillkår. 
av Rydberg » 2003-10-17 13:09
Material Quality also dramatically affects the performance of cables and their terminations. By material quality we mean both the intrinsic quality of the metal, such as gold, nickel, brass, aluminum, copper or silver, and we mean the way the metal has been refined and processed. Pure silver is the very best performing material for audio, video or digital. However, if silver is not carefully processed, even low grade copper will sound better. Silver has also earned a confused reputation because sometimes the term "silver" is used to describe silver-plated copper. When carrying an analog audio signal, silver-plated copper causes a very irritating sound, sort of a "tweeter in your face" effect. In a different application, such as video, RF or digital, good silver-plated copper becomes an extraordinary value, out-performing even the highest grades of pure copper.
Why no gold wire? Because gold has neither low distortion nor low resistance. Gold is used on connectors because it is a "noble" metal, it doesn't corrode easily. Because gold is "noble" it is ideal for protecting more vulnerable materials like copper and brass. The nature of gold's distortion is mellow and pleasant, which makes it preferable to the irritating sonic signature of nickel. A bare copper or brass part will outperform a gold plated part, but only until the metal corrodes. In comparison, high quality thick silver plating actually improves performance. Silver is not noble like gold, but it does resist corrosion and it enhances performance.
As for conducting materials, normal, high purity (tough pitch) copper has about 1500 grains in each foot (5000/m). The signal must cross the junctions between these grains 1500 times in order to travel through one foot of cable. These grain boundaries cause the same type of irritating distortion as current crossing from strand to strand.
The first grade above normal high purity copper is called Oxygen-Free High-Conductivity (OFHC) copper. In fact, this copper is not Oxygen-Free, it should more properly be called Oxygen-Reduced. OFHC is cast and drawn in a way that minimizes the oxygen content in the copper: approximately 40 PPM (parts per million) for OFHC compared to 235 PPM for normal copper. This drastically reduces the formation of copper oxides within the copper, substantially reducing the distortion caused by the grain boundaries. Additional improvement can be attributed to OFHC copper having longer grains (about 400 per foot), further reducing distortion. The sound of an OFHC copper cable is smoother, cleaner, and more dynamic than the same design made with standard high purity copper.
Not all OFHC is the same. If the poorest copper were given a value of one, and the best was a ten, then OFHC ranges from two to four-it is actually a range rather than a single performance level. Since the most important audible attributes are due to the length of the grains, we use the name LGC (Long Grain Copper) to describe the very best OFHC.
The next higher grade is an elongated grain copper sometimes called "linear-crystal" (LC-OFC) or "mono-crystal". These coppers have been carefully drawn in a process that results in only about 70 grains per foot. Cables using LC-OFC have an obvious audible advantage over cables using the same designs with OFHC or LGC. From 1985 to 1987 several AudioQuest models benefitted from this quality material.
In 1987 AudioQuest introduced FPC (Functionally Perfect Copper) in the higher models. FPC was manufactured by a process called Ohno Continuous Casting (OCC).Through this process, the metal is very slowly cast as an almost perfect single crystal small diameter rod. This near-perfect rod is then carefully drawn to maximize grain length. However, OCC is a process, not a material. The metal (usually aluminum or copper), the purity, and the size of the cast rod all make a tremedous diference. FPC copper was drawn from a smaller rod, causing less damage to the near perfect cast state, a single grain was over 700 feet long. The audible benefits were very obvious.
A couple of years later the "nines" race began. This refers to how many times the number "9" can be repeated when specifying a metal's purity. In 1989 AudioQuest introduced FPC-6 in the highest models. FPC-6 had only 1% as many impurities as FPC. The prime contaminants in very high purity (99.997% pure, four nines) copper, like LGC and FPC, are silver, iron and sulfur, along with smaller amounts of antimony, aluminum and arsenic. FPC-6 was 99.99997% (six nines) pure with only 19 PPM of oxygen, 0.25 PPM of silver and fewer than 0.05 PPM of the other impurities. The improvement was dramatic. From 1989 to 1999, many of AudioQuest's most famous models used FPC-6.
As with OFHC and OCC, the nomenclature "six nines" or "eight nines" has almost no meaning. All else being equal, higher purity is a straight forward benefit. However, grain structure, softmess and surface finish can each make more difference than a "nine" or two. Then there is the matter of measurable purity. Due to contamination caused by the measuring process, there is a serious question as to whether any metal can be verified as having greater than six nines purity. Also, since "nines" became a selling point, some quite absurd and dubious claims have been made. Let the ears beware.
Once copper has been processed and refined to the Nth degree, the only improvement left is to go to a long-grain high-purity silver. AudioQuest FPS (Functionally Perfect Silver) is just such a superior material. It was expensive, but the results were transparency, delicacy, dynamics and believability that weren't possible any other way... until PSC copper. FPS silver is still used to excellent effect in many CinemaQuest (from AudioQuest) wideband cable.
In the previous several paragraphs a number of important metallurgical concerns have been litsed, such as purity, grain structure, softness and surface finish. Earlier in the discussion of skin-effect it was mentioned that the only place with 100% magnetic field and current density is at the surface of a conductor. This means that the surface purity and smoothness does more to define the sonic character, or hopefully lack of character, than any other part of a conductor. This is why AudioQuest's recently introduced new range of metals are called "Perfect Surface."
Perfect Surface Copper (PSC) is drawn and annealed though a novel proprietary integrated process which creates an exceptionally soft copper conductor with an astonishingly smooth and uncontaminated surface. Ever since the beginning, AudioQuest cables have improved over time. Starting in 1987 with FPC copper, a foundation was created by four levels of superb conducting materials. On this foundation, refinements such as SST continually provided further discrete improvements. With the introduction of PSC copper, a whole new foundation has been laid. For a price not much higher than FPC, PSC offers more natural and accurate performance than even FPS silver. AudioQuest's CV-4 speaker cable is identical to Type 4 in every way, except for the use of PSC copper instead of LGC. Coral interconnect is identical to the previous Ruby and Quartz designs, except for using PSC instead of FPC (Ruby) and FPC-6 (Quartz).
[/quote]Skin-Effect is one of the most fundamental problems in cables. It is useful to think of a metal conductor as a rail-guide. Electric potential is transferred as current inside a metal conductor and as a magnetic field outside the conductor. One cannot exist without the other. The only place that both magnetic field and current density are 100% is at the surface of a conductor. The magnetic field outside a conductor diminishes at distances away from the conductor, density is 100% only at the surface of the conductor. Something similar is true inside the conductor. Skin-effect means that current density diminishes at distances away from the surface on the inside.
There is some disagreement as to whether skin-effect is relevant at audio frequencies. The argument concerns whether skin-effect causes damage other than simply power loss. Since the 3dB down point (50% power loss) for a certain size strand might be at 50,000Hz, not everyone understands the mechanism by which skin-effect is a problem at audio frequencies (20-20,000Hz). However, the problems are very real and very audible. This is because well before skin-effect causes a substantial power loss, it causes changes in resistance and inductance. Skin-effect causes different frequencies to encounter different electrical values at different distances from the surface of a conductor.
If a single strand is too large, skin-effect will cause each frequency component of an audio signal to behave differently. Each frequency component will exhibit a unique current density profile. The result is that some of the delicate high frequency information, the upper harmonics, will be smeared. We hear sound that is dull, short on detail and has a flat sound stage. The energy is there, the amplitude (frequency) response has not been changed, however the information content of the signal has been changed in a way that makes it sound as though the midrange notes have lost their upper harmonics.
There is a textbook equation which describes the reduction in current and power density at any depth from the surface of an electrical conductor. For copper the equation is: 6.61 divided by the square root of the frequency (Hz) equals the depth in mm at which the current density will be 1/e. Since 1/e is 37%, this equation tells us the depth at which the current density has been reduced by 63%. For 20,000Hz, current density is only 37% at a depth of 0.0467 mm, which is the center of a 0.934 mm (18 awg) conductor. Conventional use of the above formula falsely assumes that it is acceptable to have a 63% reduction in current flow and an 86% reduction in power density at the center of a conductor. However, this formula does not by itself describe at what depth audible distortion begins. Listening (empirical evidence) shows that audible distortion begins at somewhat lesser depths.
There is a solution to skin-effect-using a single strand of metal which is just small enough to push skin-effect induced audible distortion out of the audio range. Simple evaluation of multiple sizes reveals that audible skin-effect induced anomalies begin with a strand (or conductor) larger than 0.8 mm. A much smaller strand yields no benefits but encourages the problems discussed below.
A common misunderstanding of skin-effect results in the claim that "the bass goes down the fat strands and the highs go down the little strands." The surface of a fat strand is just as good a path as the surface of a thin strand, only the fat strands also have a core which conducts differently. In cables with fat strands which are straight and little strands which take a longer route, the path of least resistance at higher frequencies is actually the surface of the fat strands. Since the lower frequencies are less subject to skin effect, they travel everywhere in all the strands.
av plinius_mannen » 2003-10-17 18:41
av VelociRaptor » 2003-10-20 12:52
av VelociRaptor » 2003-10-20 13:17
Mnjae... Låt mig bara med emfas säga: Jag inte tror någon försoning behövs. Jag är inte osams, varken med Rydberg eller Velociraptor. Tvärtom ger jag dem båda helt rätt. Jag hoppas detta är ömsesidigt.
av IngOehman » 2003-10-20 21:42
av Bravo » 2003-10-24 22:51
En mille till en STEREOanläggning, mmmmmm låt se, lite snålt med stålar men något skall man väl kunna hitta.
av dimitri » 2003-10-24 23:44
av IngOehman » 2003-10-25 19:00
av Erik_Johansson » 2003-10-25 20:12
av AnotherDrinkPlease » 2003-10-25 23:53
av IngOehman » 2003-10-27 01:44
, men jag minns inte helt säkert.
av AnotherDrinkPlease » 2003-10-27 14:15
av Hefty » 2003-10-28 13:11
av Naqref » 2003-10-28 13:32
Hefty skrev:Då blir det 470' över till Högtalarna, det borde väl räcka men om någon vet vad dessa skönheter kostar så skulle det vara kul att veta.
av dimitri » 2003-10-29 11:32
av dole » 2003-10-29 11:38
av Bart-Art » 2003-11-02 01:14
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