Brass versus copper binding posts

I prefer solid copper binding post with heavy silver plating to prevent corrosion. See below:

Mike

ETI Research KRYO Binding Post

ETI KRYO Binding Post - $149.00 (single pair) Enter Quantity --->>

The ETI Research Kryo Binding Post is like no other on the market today. The conductor is made from Silver-Plated Tellurium Copper for not only superior conductivity but long-lasting durability. ETI believes this is the most transparent sounding binding post on the market today. CONDUCTOR: Silver Plated Tellurium Copper. HOUSING: Brass (Black Finish). Sold as ONE PAIR (1 red and 1 white post). If purchasing for a stereo amplifier or stereo pair of speakers, you will need FOUR posts (two pairs). Each pair contains one white, and one red color coded post.

Thanks again for all the help everybody. I contacted Usher in Taiwan and they emailed me that yes the binding posts are brass. The ETI items shown above were actually my first choice. I use their XLR connectors from the same family on my interconnects. Being that I would need four sets ends up to $600 to make the change that’s a lot of money. I have found a company named AECO in Taiwan that makes a similar binding posts for $60 a pair rather than $150. Model number ABI-0611 followed by a suffix of G, S or R that designates gold, silver or rhodium plating directly onto tellurium copper. All of my speaker cables are Clear Day silver with silver plated spades and bananas. So I think I will be ordering the silver plated versions.

Those connectors are very good. The KELI connectors are very good also.

@ditusa,

Silver does not prevent corrosion. In fact the silver surface is fairly reactive and can corrode fairly rapidly depending on the number of silver atoms on the surface that are not fully coordinated. Unlike copper which oxidizes to the +1 oxide (Cu2O) and +2 oxide (CuO), silver does not readily form oxides. Instead silver readily forms a sulfide (Ag2S). Both silver sulfide and the oxides of copper are semiconductors with similar band gaps.

Ah, those darn connectors.  Seems there is no perfect solution.  Gold and Rhodium don't oxidize, but they are not very good conductors.  I had an silver plated AQ rca plug that literally turned black.  That can't be good.  

Here is another fact to drive ones OCD nuts.  Just read how tin plated conductors react with gold.  So that is another often ignored no-no. 

How about low mass copper to copper treated with ProGold?

In the end, it will be a compromise like most things in life.