Monday, March 17, 2014

On Esoteric Wire...

Conductor types and purity have often been a topic of hot debate where on side endorses use of exotic materials and another snubs up their noses at any audible benefit. To set the historical record straight, below are some notes that should help you understand why this topic seems to rear its head so frequently.

Back in the early 1970s, someone questioned one of the most overlooked and common components in every audio system: the material used for wire or conductors. Since once cannot escape wires in interconnects, speaker cables, speaker voice coils, phonograph cartridges, internal chassis wiring, and circuit boards, this seemed to be a logical area for investigation. If there were an advantage to moving to a different material, there were a diverse number of places it could be implemented. A few companies introduced speaker wires and interconnect cables in response to this curious question touting this or that advantage because of this or that feature. In reality, most claims were fruitless and sheer marketing hype.

This doesn’t mean that there were not differences between conducting materials – there are drastic measurable differences – but when marketing spun the assets of these features they turned out to sound more like snake oil than science. After a prolonged learning curve, these marketing goons learned what did and did not work when pumping up the benefits of their products and today buzz words associate fair, good, better, and best conductors. (BTW, I love these goons since they are the people responsible for advancing sales and therefore the advancement of the high-end itself, but often question their choices of words or stand on reasoning.) Before jumping into the fray of these buzz words, let’s review a bit of historic around conductor materials.

When wires were first needed, scientists analyzed which pure materials (not alloys or processed metals) had the least opposition to electrical flow and in the order of their “conductivity” (electrical resistance per unit length) are from best to worst are: silver, copper, gold, aluminum, zinc, and nickel. So the best conductor was silver with copper a very close second. Two characteristics of silver eliminated it from the desirable material list since it was expensive and it easily oxidized. Copper was therefore the number one choice (see a highly descriptive resistivity table for all electrically conductive elements in the periodic table at

With the introduction of computers and high-speed electrical signal technologies, coated copper materials were developed to improve high-frequency characteristics. Called “wire-wrap wire” this coated copper also came in a new manufacturing process introduced in 1975 called OFHC (oxygen free high conductivity). Here, oxygen normally encountered in is production is eliminated from the extrusion process thereby improving its conductivity. Another refinement also improved conductivity by eliminating normally-encountered impurities (called high-purity or HP). Again, audio manufacturers swarmed behind this new process and introduced a variety of cables featuring this new type of copper.

Recently, a further copper refinement process was patented by Professor Ohno of the Chiba Institute of Technology in Japan that reduces the number of fractionated crystal structures and other impurities. Termed the Ohno Continuous Cast (OCC) copper, this metallurgical process uses a heated mold for casting and extruding, with cooling taking place in a separate process. The result is ultra-high purity copper with a larger crystal size.
Copper Type
Oxygen Impurities (PPM)
Hydrogen Impurities (PPM)
Traditional (TCP)



With these results, the OCC process creates "ultra-pure" (UP), also known as “ultra-high purity” (UHP), copper and the abbreviation for this material is UP-OCC. (See for more information on current high-technology metallurgical manufacturing processes for copper.)

Oxygen Free Copper (OFC): Oxygen free copper was developed in Japan around 1975 as it became increasingly apparent that sound quality was related to the quality of copper and the processing used during cable manufacture. OFC is produced is a carefully controlled oxygen free environment resulting in a significant reduction in oxygen content (10 ppm). There are fewer crystal boundaries in OFC which results in much higher performance than TPC where the numerous crystal boundaries cause a degradation of the audio signal.

Linear Crystal Oxygen Free Copper (LC-OFC): In 1975 Hitachi improved the OFC process to further reduce impurities and crystal boundaries. The patented LC-OFC process developed by Hitachi re-heats the copper following extrusion which reduces impurities between the crystal boundaries as the copper crystal expands. This in turn leads to a longer overall crystal length. A typical crystal in a 1mm diameter LC-OFC conductor is 130 mm long which can be compared to typical crystal length of 4mm long in TPC conductors.

Ultra High Purity Oxygen Free Copper (UHP-OFC) is processed much in the same way as OFC but is also subjected to a further Zone Refining process (developed by William Gardner Pfann). With Zone Refining the purity of the copper crystals is increased by drawing a narrow molten region of a crystal. This molten zone is moved along the crystal (in practice, the crystal is pulled through the heater). As the molten region melts it leaves a wake of purer material solidified behind it. The impurities concentrate in the melt, and are moved to one end of the conductor whilst it is being drawn.

Ohno Continuous Casting (OCC): In 1985 Professor Ohno from the China Institute of Technology developed his patented method for the extrusion of a grain free copper wire. When a pure metal solidifies, its crystals grow in a specific geometrical pattern (typical to that metal) emanating from a nucleus, rather like the dendritic growth pattern of a tree. The size of the metal crystals grown can be varied by repeatedly annealing metal such as is done in the LC-OFC process. The structure of a strand of copper may be likened to that of a bag of sugar. Every grain of sugar has a crystal boundary. In a conductor, these crystal boundaries (potential barriers) act as a non-linear resistance to the flow of electric current. It follows that, the fewer the boundaries, the less the effect there is on an electric signal as it propagates from one end of the conductor to the other. The Ohno Continuous Casting method re-heats the extrusion as the molten copper is forced out of the mould and very slowly and gradually draws the grain or crystal down the conductor's length, creating a 'single crystal structure'. The typical crystal length of OCC copper is more than 200m.

So what’s the conclusion from this? In 350BCE, Aristotle wrote that women have fewer teeth than men and everyone did not question Aristotle because…well he was Aristotle, someone much smarter than most ever would hope to be just do not question these sort of things. But one day, someone got a brainiac idea, “Let’s count them!” What a concept. And sure enough, men and women both had the same number of teeth proving that even the great Aristotle could make a mistake. WOW! This means that even the brightest minds can learn a few things since their followers are taught to blindly do what they were told…until someone doesn’t. This is how advances are made – by questioning authority and finding out if what was once believed to be true still is - or is not.

Technology advances every day and sometimes several times a day. Our understanding of the world and how it works constantly evolves and with it should our reasoning for accepting old facts. What was once understood by one set of physical laws will always change once our understanding of these laws advances. It was once believed that the world was flat and the earth was the center of the universe. Anyone who disagreed was considered at the least off his/her rocker and at the worst a heretic and put to death. Skeptics have a purpose in keeping those of us who wish to investigate our changing understanding in one word "honest." Truth must prevail but even skeptics can be biased since they adhere to what they know – which may be an old understanding to which they unquestioningly now regurgitate the words of their teachers.

What I am trying to say is this: keep an open mind and even though the reason someone states that this is why something like wire sounds better than this other conductor, it is the goons who write the words you read (or even the idea maker her/him self) that may not be quite right. This does make the advancement any less justified; it is that we as human beings always struggle explaining what is going on with a new discovery of change. One day, Einstein, Stephen Hawking, every skeptic, every critic, you, and I will all be proven wrong. It is inevitable; all we need is more unconstrained time and open-mindedness for future generations to clearly understand why.

The best position you can take is that of neutral; neither for nor against but completely open minded. You count the number of teeth, you listen to the differences, and you make the choice. Don’t let biases influence your decisions and a better sounding system can result. Give that linear-crystal wire in our tonearm a shot, give that interconnect cable or power cord a try, and give that new CD player a go. All you can do is be wrong, and what’s wrong with that? No one ever advanced anything without making a few mistakes. Go ahead: fail and learn something new about what does not work. Then, try again.

Yours for higher fidelity,
Philip Rastocny 

I do not use ads in this blog to help support my efforts. If you like what you are reading, please remember to reciprocate, My newest title is called Where, oh Where did the Star of Bethlehem Go? It’s an astronomer’s look at what this celestial object may have been, who the "Wise Men" were, and where they came from. Written in an investigative journalism style, it targets one star that has never been considered before and builds a solid case for its candidacy.

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