Why Tellurium Copper?

Our Ghost+ cable line uses XLR, TRS, TS and RCA connectors with tellurium copper connectivity pins.  In our tests with tellurium copper vs other copper alloys we learned that the last half inch of metal used on either end of a copper wire can affect the overall performance of the cable.  

Wanting to understand why these connectors sound different than the Neutrik and Whirlwind connectors that we have used for decades, I discovered the International Annealed Copper Standard which rates the percentage of conductivity a material has relative to copper, which is considered to be 100% conductive.  

• Silver = 105%
• Copper = 100%
• Tellurium Copper = 93%
• Brass = 28%
• Bronze = 15%

Notice how low brass and bronze are on the scale in relation to copper.  It is public knowledge that all Neutrik XLRs use bronze for their female pins and brass for their male pins.  I assume they use the slightly softer and less brittle brass for the male pins that are subject to more insertion stress, and the cheaper and harder bronze for the females which are enshrouded in plastic.

Copper alloys are made to increase the tensile strength of copper, which in pure form is very soft and malleable.  Bronze is made from mixing tin with copper and brass is made from mixing zinc with copper. Tellurium is also added to copper in order to increase its tensile strength from the 30500 psi of pure copper to 47,900 psi of tellurium copper.  

Along with the strength of tellurium copper, we can see that its conductance is only 7 points below that of pure copper, making it an exceptional conductor that closely maintains the sound of pure copper wire.