What's the best plating material for interconnects plugs ?

OP the question is WHY do they plate the terminal end to begin with?

After you find out it’s always for protection and or issues with growing barnacles, make a choice.

Above copper are super conductors. Silver is the only one I know of.
Copper at 100% Silver 105%.

Nickel/silver or just nickel use to be and still is popular.. Silver, Copper Gold, for me

Tin over copper if I’m gonna bury the sucker..

Everything below that is for corrosion or just being pretty. Gold is warmer than Rhodium, it’s just a better conductor and not so hard. Rhodium is actually to strengthen and add "Spring" to materials that don’t recover well from being mechanically coupled. Say a male bullet into a female bullet connection, Rhodium acts as torque retainer for contact pressure.

This is where contact enhancers come into play. Without getting all techy there are fields being formed through materials and because of materials. By reducing the resistance between contact surfaces, we net the TRUE sound of the cabling and terminal ends, NOT encumbering the sound with a LACK of good contact..

There IS a reason terminal ends and cabling "SOUND" different.

Materials can act as minor tone controls, get to know the materials your using.

Copper is always good, you have to work at it to make copper sound BAD.. Really you do.. NOT BAD but it can be GREAT... there is a difference..

What the wire is covered with.. Holy cow...  I like teflon.. just good all around performance, last forever and not easy to harm...

Regards

Another good one, Dansk.

Just to clarify where several posters have stated that silver oxide is a good conductor, That is simply not true. Silver oxide (Ag2O) is not a conductor but a p-type semiconductor with a band gap of about 1.2 eV, so conductivity is about 1/1000 that of pure silver.

However silver oxide does not readily form on the surface of silver. The typical tarnish on silver is silver sulfide (Ag2S) which is also a semiconductor with a band gap of about 0.9 to 1.1 eV. So for both the oxide and the sulfide, the conductivity is poor compared to pure silver.

choice is clear, silver it is ! thank you all for fantastic write ups and all of you help !

Most small RF connectors are beryllium copper, tellurium copper, or brass with a gold plating for corrosion resistance. Same for audio connectors. While gold is not the ideal conductor, it's better in the long run than other materials that decay and corrode.