OP Erik - I always enjoy your informative and well-informed posts. Thanks!
There are 4 metallurgical options on the Viborg link you provided,
Each one has a brief summary as follows:
1) Gold Plated - 【Enhanced Sound Quality】
2) Pure Copper - 【Superior conductivity】
3) Rhodium Plated - 【High-quality construction】
4) Silver Plated - 【High-quality conductivity】
danmar123's reply above compared silver plated and pure copper, preferring the latter.
What's best for sound quality?
Over to All...
Thanks again,
Ken