After careful consideration it seems that a hard drive based server with USB feeding a USB DAC is the wave of the future, and since I don't currently have a CD player it seems like a great route to take. The digital data is error free if properly ripped and the jitter from the standard SPDIF interface is eliminated.
Here is some great info on the subject.
http://www.wavelengthaudio.com/usbdac.html
These DDDAC1543 MK2 kits look very interesting, are relatively cheap, and look like good candidates to be transformer coupled to the grid of a tube.
http://www.dddac.de/
Does anybody have any experience with these kits? I plan to go USB to I2S to DAC to transformer to tube.