Working on that CIEM cable got me motivated to fix this Sennheiser HD6xx cable I had made way back at the beginning of the year.
The Senn connectors deformed under the pressure of the helping hand clamps when the soldering iron warmed them up, and they would no longer fit into the ear-cups. I had ordered replacement connectors, but never got around to soldering them on.
Until now...
It's Silver-Plated Copper. I can't tell you what purity, because this wire is scavenged from another custom cable I received second hand. The original owner couldn't tell me any more about it.
This used to be covered in horrid, bright green paracord. Mini-XLR connectors, and 1/4" plug.
As you can see, it's a very different beast now.