Why Rhodium?

Rhodium has the best resistance to corrosion over any current material being used for termination. I own several audio components that have been in a cottage next to Lake Erie (high humidity) for 20 years. The heat is off 6 months out of the year with almost constant 80% - 100% humidity. Rhodium is the only material that has not shown signs of surface corrosion under this condition. Silver, copper and gold all eventually broke down with surface build up. Steel connections were rendered useless and couldn't even be cleaned.

A friend of mine and I compared two RCA cables in a blindfold listening test against each other. They were connected between a CD player with a direct output to the inputs of two mono block amplifiers. The cables were two meters long with both using identical wire with no insulation. One set of cables was terminated with a gold plated RCA plugs with soldered connections. The other was terminated with a RCA plug that was rhodium plated, set screwed and soldered. Both of us picked the same interconnect as our favorite over two separate listening sessions. We gave the rhodium plug a slight edge in the area of sound stage size and 3 dimensionality. This is, obviously, not a perfect test of plating comparison. It may say as much about the rhodium set being set screwed.