This information may be useful. I use Cardas interconnects that are about thirteen years old. I'm upgrading my system, so I decided to ask George about aging cables. This was his reply:
Most interconnects do age because surface oxide formation on the conductors causes an increase in eddy currents (swirls in the em field actually). Cardas interconnects do not age in this way because all of there strands are individually enameled when they are made. I recommend an occasional sweep (using the Cardas sweeper record or the sweep track on the Ayre CD). Other that that you cables should not require any attention in normal use. We do have a service that verifies authenticity connections etc. We check all connections verify that everything is to spec and re-shrink the cables if you have any doubts.
Most interconnects do age because surface oxide formation on the conductors causes an increase in eddy currents (swirls in the em field actually). Cardas interconnects do not age in this way because all of there strands are individually enameled when they are made. I recommend an occasional sweep (using the Cardas sweeper record or the sweep track on the Ayre CD). Other that that you cables should not require any attention in normal use. We do have a service that verifies authenticity connections etc. We check all connections verify that everything is to spec and re-shrink the cables if you have any doubts.