Onboard sound either uses a Realtek or Crystal chip or is built into a SuperIO chip (aka southbridge) almost all of the time. Data from the file to the sound card doesn’t degrade until it hits the DAC, where it may. This is one of the areas (also in acceleration and CPU utilization) where good add-on cards excell. There is quite a bit of electronic noise with onboard solutions, and so there is only a certain level of sound quality which can be reach (which has been improving, might I add … onboard sound today is usually very very good). PCI add-in cards are capable of higher clarity, and for professional solutions there is usually a PCI add-in card for all of the digital doings and the analog audio pathways and DACs are in an external shielded box. So far I see no EMU10k1 or EMU10k2 chips onboard, so until then we’re still dealing with Via, Crystal, Realtek, Intel and AMD sound solutions.