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.
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.