What's the best plating material for interconnects plugs ?

@ssg308 -  one approach to connector selection is to consider the conductivity of the metals being used

Please see this link that shows the IACS conductivity rating of various metals
IACS of Metals, Alloys and Solder (avoutlet.com)

1. Silver 106%
2. Copper 100%
3. Gold 76%
4. Rhodium 39%
5. Nickel 24  %

However - when plating - for the plating material to "Stick" to the actual metal of the pins of a connector, many times requires a substrate plating that has an even lower IACS rating

This generally means the connector will not provide the best possible performance

However - Silver Plating onto Pure Copper requires no substrate and therefore provides the best combination from a conductivity perspective

But beware - some "silver plated copper" connectors are actually made from some type of copper alloy, like Beryllium copper, which is not as conductive as pure copper, but it is more robust

What about the black tarnish? - Some people regard the black tarnish that often develops on silver (plated) connectors to be a problem. But in reality, the tarnish is only microns in thickness and can be removed simply by reseating the connector. The tarnish is regarded as a "semi conductor", so it will conduct electricity, but not quite as well as silver.

Unfortunately it is also not as simple as selecting the best IACS ratings for the various materials

My current RCA plugs are silver plated copper and they outperform many solid silver connectors. So metals are not the whole story either.

I have found the best connector uses pure copper as the base material and silver for the plating and all my connectors on all my cables are created in this manner

Gold and Rhodium has a certain "image", but they both pale in comparison to a good silver plated copper connector when it comes to sound quality.

Just another opinion - Steve :-)


 

@ljgerens - I do not know the science that goes into plating, but these guys seem to now about the Silver plating onto copper in the field of electronics
Silver Plating of Copper or Copper Alloys - Advanced Plating Technologies

They appear to confirm what you have said - almost to the letter

But they also state that for "pure copper"

The copper can then receive a nickel underplate (if specified) followed by a silver strike and finally the silver plating. The silver strike layer is very important to achieve an adherent silver layer and avoid silver immersion that would result if the copper was immediately silver plated without a strike.

So the nickel underplate seems to be optional and the Silver strike takes care of adherence

But on the more practical side of things - I trust my ears and after many years of listening to different materials on a variety of connectors I find the following to provide exceptional performance

1. KLE Innovations Absolute Harmony Silver plated RCA plugs
2. KLE Innovations Harmony Silver plated Banana
3. Sonar Quest Silver plated Copper Mains and IEC connectors

Keith Louie Eichman has spent a lifetime (close to 40 years) making connectors and cables and it seems he has an affinity for silver plated copper and based on the excellent performance of his products - he must be doing something right.

And I am yet to find any connector that will compete with the dynamic performance of these connectors at a similar price point

With respect to tarnish - none of my connectors are exhibiting any signs of tarnish on the "contact areas" of the plugs and that is after approximately 6 years of continuous use.

Tarnish will only occur where an area is open to atmospheric Sulphur and due to the lack coal fired electricity up here in Canada the amount of Sulphur appears to be minimal

• e.g. The areas of the Banana plugs I currently use that is exposed to the "air" is only recently started to colour a very faint brownish tinge
• But the area inside the binding post is still very white.

For folk out there that dislikes the thought of any tarnish buildup I would suggest you use Gold.

Personally - I would ONLY choose Rhodium if there is no other option.

But that’s just "my personal preference"

Regards - Steve

@ljgerens - good to know, but it will not change my mind about Silver plated connectors. They are simply my preference

But others are free to choose otherwise on reading your posts above

After all - We are each entitled to an opinion.

Regards