In 1979, Ray Kimber was working in professional sound and lighting and was trying to solve what was then a relatively new problem. The speaker cables he was working with at the time were picking up noise from the lighting system and causing a clearly audible drop in audio quality. His solution was to counter braid the conductors, surmising this would cancel out any magnetic interaction. A solution provided through ingenuity, thus Ray decided he had a marketable idea and began Kimber Kable. He literally began by hitting the pavement, walking into dealers with his cables to demonstrate the difference, and his reputation quickly spread.
Fast forward to today and Kimber Kable is one of the most well-known cable manufacturers in high performance audio. Kimber has an interesting business model in that they offer products that cater to audiophiles in every budget category. They offer very fine interconnects, power cords and speaker cables for the entry level hobbyist as well as cables in their Select series for those willing to pay more for a higher quality. They also offer plenty of cables priced for those of us in the middle of the pack, but which are made with the same obsessive attention to detail.
For this survey, I was supplied a half meter sample of the following interconnects; the Hero Ag, KCAG, and the KCTG. All were terminated with what is considered to be the one of the finest, if not the finest RCA connector around, the WBT-0102-ag. This ultra pure silver connector is designed and manufactured in Germany to typical German engineering standards. It is a locking type that features EMI (Electro Magnetic Interference) shielding as well. It is an expensive connector, costing as much as some of the other Kimber cables I own.
As for the cables themselves, the Hero uses a four wire braid with a shear black Techflex outer jacket. The KCAG uses a three wire braid and the KCTG uses a six wire braid. The silver conductors are 20AWG with a Teflon coating. Grading on appearance, all three cables are beautifully finished and befit the Kimber reputation of or superior craftsmanship. The KCTG is an especially beautiful looking cable.
According to Nate Mansfied, National Sales Manger for Kimber Kable, the KCAG is a three wire braid utilizing 20AWG Teflon coated stranded conductors. The HERO on the other hand is a four wire braid of the similar conductors with the addition of a techflex sleeve for cosmetic purposes. Kimber calls the silver conductors AGSS. They are made from seven conductors in five different sizes with a clear Teflon jacket. All conductors are drawn using a unique extrusion process.
The process starts with bars of pure silver. Before further processing, these bars are carefully cleaned with a mechanical/chemical process. The bars are then formed to rod stock. During this step, other additives are compounded to stabilize and prepare the silver for its future design as Kimber Kable AGSS wire. The rod stock is carefully cleaned to prevent oxidation and dirt from permanently being embedded during the drawing process. During the reduction process the rod stock is drawn through a series of diminishing sized diamond dies until the final wire size is reached. Compared to usual procedures, Kimber uses a larger number of reduction steps in the drawing process.
The speed, pressure and heat are also substantially lower than usual. Special chemicals and lubricants are continuously sprayed on the dies to reduce friction. They also inhibit long and short term oxidation. The end result is a very high quality silver strand having unique several advantages. Kimber says low heat is best. The reason for reducing the silver in many small increments instead of a few large steps is that it eliminates the massive friction induced heat buildup that would otherwise exist. Heat during the drawing stages causes many surface irregularities and disruptions. By minimizing the heat, there is a much smoother skin on the strand.
Heat allows drawing chemicals to combine with the conductor surface resulting in impurities and other surprises permanently embedded in the skin of the conductor. Heat also causes the surface to be heat treated or annealed. The annealed skin of a strand does not have the same conductivity characteristics as the core of the strand. Skin effect is worth an article on its own, but suffice it to say that simply reducing the strand size can create unwanted results. It should be pointed out that if copper or silver is reduced to a very small gauge strand (smaller than gauge size 30 or so) unavoidable and undesirable characteristics likely result.
Drawing to very small diameters requires high speeds are used. Thus the inertia of speed will prevent the strand from being snapped as the material is being pulled thru the reduction dies. This high speed causes high heat which results in severe surface to core inconsistencies as discussed earlier. But since the conductor is so fine, degrading by heat is exaggerated because the strand itself cannot act as a heat sink. Thus the depth of annealing and surface disruption goes even deeper in an already smaller strand.
So as we can see, the process is very involved. This is a very expensive and time consuming process. Suffice to say Kimber is extremely meticulous and exacting in its procedures.