Silver cables added resolution

Silver and copper, the materials the conductors are made out of, are but a line item on a very long list of things that matter.

I have no idea what mains noise is, or if that even is what you are hearing. Also what you are calling "added resolution" let's just say, "I hope not." Resolution can never be added. It can be improved. But resolution is the ability to resolve or see fine detail. Fine detail can never be added, it can only be revealed. Anything added, detail or otherwise, is by definition distortion. Sad to say, part of the "detail" you're hearing may well be distortion in the form of ringing that because it is high in frequency is often times mistaken for detail.

That about covers it.
Mains noise perception???

Generally:Copper warm
Silver coated copper good resolution nice balance
Silver... you better have really good components and break it in for hundreds of hours. Can be very resolving but can sound thi.

High end companies do sophisticated things to make cables sound good. Lessor companies sound like the metal they use.

Hmmmm, I think your issue may be more of lack of shielding. Did you go from shielded cables to unshielded?

Silver has a superior conductivity over copper, just a scientific fact.  This can have an effect on the end result, depending on how revealing the rest of the system is. 

Added resolution is just the result of doing less harm to the original signal at the source.