Just an update to my earlier post and a fairly thorough reversal. According to people who know more than I do about music servers, they do make a difference, even with JPlay. That's from the people who developed JPlay. So, I stand corrected and that's good.
In fact, J of JPlay says that everything in the reproduction chain makes a difference, e.g. usb wire.
Also, I read that Windows 8 is noticeably better at sound reproduction that earlier versions.