It's not the oxide but the sulphide (Ag2S) that's the issue. That's mostly what silver 'tarnish' is. Ag2S is a semiconductor and not a good conductor, at least as far as I know. In thin film it might not be an issue, but we use gas for cooking which always has some sulphur in it, and we eat a lot of curries, so the silver will be exposed to moist, sulphurous gases encouraging tarnishing. At least we don't have a coal fire
There's a document here which shows significant increase in contact resistance with tarnished silver-plated contacts:
http://www.te.com/documentation/whitepapers/pdf/Performance_implications_Silver_Myers2009.pdf
Personally I would rather have gold plating as I don't think my ears can hear such differences any more (darn middle-age and SSHL
).
That said, my NightOwls are sounding incredible, even more than when I got them. I think they are loosening up nicely now. I've been listening to a SACD ISO rip of Dire Straits' Brothers in Arms and it just blew me away!