Why Rhodium?

I picked up a Furutech FI-28M (R) which is rhodium over pure copper. It's very smooth with great dynamics and soundstaging. I also use Kaplan cables. Several with all copper ends, and one with rhodium over copper for my source.

In my experience, the rhodium is generally tonally neutral while adding smoothness, dynamics, and detail. Other platings such as gold or silver may tilt the tonal balance.

IMO, the issue is more complex than just conductivity of the plating as a cause for differences in sound with various platings materials.

The FI-28M(R) appears to be the “little brother” to the FI-50, both being made of rhodium over pure copper. I suspect the sonics are similar. I've found the FI-28M(R) to have excellent dynamics, smoothness, transparency, detail, decay, and soundstaging, while remaining tonally balanced, with no glare.

My rhodium plated Kaplan cable sounds slightly more lively and detailed, as compared to the pure copper version. The cordage is the same.

I know that some rhodium connectors use a silver underplating. Perhaps that is the source of the glare?

I don't believe that rhodium will necessarily cause any loss of detail or transparency, as compared to a higher conductivity material. My experience is just the opposite.

I’ve also tried the FI-25Gs, but they sounded somewhat bright, with some glare.

Another example of interesting material is palladium. I use a Pure Note Alluvion digital cable, and the palladium in it sure takes the glary edge off of the silver. However, this is an alloy, and not a plating.

Nickel is another story. It always seems to cause glare for me.

Well I hear differences, but my hearing and system are quite good. Granted, some differences may be subtle, however others are quite obvious. For example, silver sounds very different than copper.

Just this weekend I've been comparing outlets, the Hubbell 8200/8300 and 5362. The only real difference is that the 8200/8300 has nickel plating whereas the 5362 does not. The presentation is different, with the 8200/8300 being more forward, brighter, and a bit of glare. I attribute the differences to the nickel plating.

I have a friend that is a cable denier. Whenever he comes to my house he pokes fun at the fat hose pipes that adorn my system. Last time he was over he commented that I had more bass then before, and what had I changed. When I told him it was only one IC and a PC, he just grinned.

In my example I was referring to silver and copper platings such as AC and RCA connectors. In regards to cables I would tend to agree to a point. Certainly geometry, dielectric, etc., have a significant effect on the sonics. However, I also believe that materials impose some audible character on a cable. I’m certain there are some designs that may minimize the effects.

As I previously mentioned, the Pure Note Alluvion digital cable I use is a palladium-silver alloy. I’m quite certain that palladium is used to remove the edge off of the silver, and it’s quite effective in my view. Other vendors such as Silversmith and Siltech use materials such as palladium and gold in their cables. I’m not sure one could replicate the sonics of some of these cables via geometry and dielectrics alone.

Rja, I agree, brass is ok, but has limitations. Pure copper tends to sound better to me, and is usually a safe bet for just about any interconnect or PC. FYI, I use a mix of cables and PCs. Some are high purity copper, and some are copper-silver hybrid (separate types of wire). A couple of rhodium plated connector PCs are also used in strategic places.