Besides the soundcard.... does the computer itself

the celeron and p4 should make everything worse. go with a 64 bit AMD processor which is more advanced :)

seriously, none of the listed components should make any difference in sound quality.

Some people think that external "sound cards" are better than ones inside the computer. Due to less electrical noise from the PC components. I'm talking about external units that hook up via USB or Firewire ports. Personally I haven't had any experience with those external devices.

I'd stay away from Celeron processors as they're just not as powerful as a P4 or AMD chips. But that's not based on how it sounds, just how fast and how well the computer works. AMD have generally been more focussed on gaming applications so are more geared towards audio and visual appplications than Intel chips.

Oh yeah, and if you add the Mo-Pingo Puc's it will improve the sound. :)

They do make a tube sound card out there, but I think I leave the tubes and their heat in the basement where they can warm the ambience of the concrete walls.

If you have a digitial noise problem, due to a cheesy power supply, that can make a difference, shielding of the PS could help.

The processor speed can cause glitches, and speed of your modem if you stream audio will be a factor, but frankly if your streaming audio, quality is not a word I associate with that sound. If your using it as a server or CD player it's different. More significant will be the amplifier section. I would try and pick up an outboard amp, and leave the high voltage outside the PC.

loon

Does the poer supply have any effect? Some have tighter voltage specs than others.