The sound quality on the analogue audio outputs is pretty dire on most PCs yes. The best thing to do is get a Dolby Digital cinema amp and use optical or coax digital out from the PC. Works a treat for me and most motherboards support either/or optical or coax digital out.
No, I don't think the original poster wants a PC card that one would use for home theatre or gaming if he's using music recording applications.
What he wants is a low-latency pro or semi-pro audio card made for home recording / studio recording applications. M-Audio makes good cheap cards like this: the "Delta" or "Audiophile" line.
http://www.m-audio.com/products/en_us/Audiophile2496.htmlBut before all of this, I would try playing with the audio buffer settings in your computer's audio software. Try playing with the audio buffer settings in Fruity Loops or whatever music software you are using. Also make sure the audio driver selected in these applications is ASIO or ASIO compliant.
http://rainrecording.com/pro/software/adjusting-pci-latency/Also download the driver ASIO4ALL. It gives ASIO ability to commercial sound cards (i.e. non-pro sound cards like the one on your motherboard) and may cure your problem (along with the buffer settings mentioned above).
http://www.asio4all.com/
