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Peter Wieck[_2_] Peter Wieck[_2_] is offline
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Default Do RCA plugs/sockets have a galvanic corrosion problem?

Short answer:

Yes, they *can* have a galvanic corrosion problem.
However, it is a very easy problem to eliminate.

Getting down to specifics with some background first:

a) Gold is not a particularly good conductor, and when alloyed, even less so. It was chosen for use mostly in aerospace applications as it is resistant to corrosion, so in a satellite application, the high cost was not an issue - as one example. Gold moved into audio applications mostly because a class of vendors and merchants determined that a few cents worth of gold was the functional equivalent to many dollars worth of profit. And an entire industry was born around boutique cables for which there is not one single, solitary comprehensive study in its support.

b) Fine silver is very nearly as resistant to corrosion as fine gold, and as close as there is to a room-temperature super-conductor. Coin or sterling silver is subject to sulphur corrosion (not oxidation), which as we burn less coal is reducing somewhat. But either is still a better conductor than copper or gold.

c) Cadmium, the once-and-former plating-of-choice has (rightfully) fallen out of favor based on its toxicity (why did Van Gogh cut off his ear?). In any case, cadmium salts are not happy in a low-voltage signal path - they can rectify (act as a diode) at rF frequencies, often with unfortunate effects.

d) As the snake-oil industry has yet to use fine silver for jacks and plugs, and as gold is a poor choice for audio applications anyway, the best choices are either nickel or tin. As a plating material, tin is a very slightly better conductor than nickel. As a wearing material, nickel is both better and much harder than tin as well as being slightly more lubricious.

Cutting to the chase: Most base-metals for jacks and plugs is either spring bronze or brass, with bronze being the better for jacks, and brass being the better for plugs. Tin takes solder better than nickel - and soldering nickel directly requires skill and the correct materials and tools. You will find that high-end nickel plated jacks have tin-plated soldering lugs for that reason. As a matter of good habit, one should remake all audio connections at least once per year in a conditioned climate, once-per-quarter on the West Coast, eastern Mid-West or South, and twice per year on the East Coast. All of them - speakers and patch-cords. Four times per year anywhere in England or Europe. Saudi, Dubai (UAE) once per quarter as with the Middle East in general. I have not experienced other regions or climates for long enough to advise, but the more polluted, or closer to salt-water, or high humidity, the more frequent the need.

DO NOT:

a) Use any sort of chemical anti-oxidant. The material is persistent, and if not entirely and completely removed after use, the reaction(s) will continue until the active materials are consumed. Not good.
b) Use any sort of conductive abrasives such as steel wool, nail-file or similar.

DO:

a) Use a non-conductive soft abrasive such as a drafting eraser. I have found that the best tool on the planet for the purpose is an electric drafting eraser with a soft element. https://i.ebayimg.com/images/g/G1YAA...FG/s-l1600.jpg I keep one of these with a life-time supply of elements (these are also excellent for cleaning circuit-board, connectors, tube-pins and similar).
b) A variety of dental-picks can be your best friend for tightening jacks and cleaning corners on plugs - if needed. *ALWAYS* do this when doing the service in any case.

Keep in mind the nature of the beast. For the voltages, surface areas, and cord-lengths under discussion in the Audio World, metals, alloys, and materials are largely irrelevant making the first-assumption of well-made items and appropriate means, methods and materials in the first place. So, tin-against-nickel-against-copper-against-gold-against-tin-against-brass-against-bronze, if kept clean and tight, is all-the-same in the real world. To the chagrin of the snake-oil distributors and the boutiques that they support. Good tools are seldom overly complicated. Overly complicated tools are seldom good.

Enjoy!