Having found that the quality of sound pumped through the amplifier via the PC's built-in sound card was far from ideal I decided to investigate alternatives. I could look into spending some money on a better sound board, preferably an external one where the noise interference should be reduced or I could look into buying a USB DAC. I didn't really want to spend much money and while researching options I found a pretty cheap one in the Silverstone EB01. The reviews for it were generally very good. Around the spring of 2008 I bought one for $85.
So I hooked it up to my PC and amplifier and found that the device was listed as USB speakers in the audio setup for the PC. The difference in sound between the build-in sound board and the USB DAC was night and day. The one annoyance was that the volume on the PC had to be set to the maximum and the volume controlled on the amplifier itself. This was (for me at least) an acceptable level of sound quality and I could always look into buying a better quality one in the future.
The next problem to tackle was now how to control playing the music on the PC in the office while I was in the family room.