Wire is supposed to conduct a signal, and some insulation is a nice feature. End of story. If you're hearing profound differences like the ones you describe merely by switching wires, one (or more) of them is damaged, or unsound design-wise, or something is out of whack in terms of cable routing (past an interference source?) or lack of insulation or damage to the cable or termination itself.
When I switch from a good cheap interconnect to a good expensive one, sometimes I hear a little more of what the source can do, sometimes I don't.
Given how much you're sweating this, I would just go to Radio Shack, buy some $15 gold interconnects, and spend the money you're going to piss away on wire on upgrading components...an area where you will hear a noticeable difference.
When I switch from a good cheap interconnect to a good expensive one, sometimes I hear a little more of what the source can do, sometimes I don't.
Given how much you're sweating this, I would just go to Radio Shack, buy some $15 gold interconnects, and spend the money you're going to piss away on wire on upgrading components...an area where you will hear a noticeable difference.