Can i use a PC as a preamp?

Hey all, OK yeah stupid question, but im unsure of the answer and hate to assume.

Im building my new system, and have gotten 2 used Technics SE-A5 MKII amps, and ive got speakers to test them on, but i havent settled on a preamp yet. But id really like to test the AMPs. I cant think of a reason why my PC wouldnt serve as a preamp, i mean when you hookup PC speakers, all they need are built in amplifiers, so stands to reason that my PC is acting like a preamp, right ..?? Am i missing something?

Will this work ? At least enough to test out the amps?

Loookin forward to the usual great help,
Shawn
PS i wont be hooking anything else up to the PC for now, ill just use Winamp and MP3s, i just want to make sure the amps work (they prob wont get a full test run till i decide on a preamp, but i wanna make sure theyre not duds)