Hi.
Im using sometimes applications like fruity loops, renoise and reason under a pendium d 3ghz with realtek onboard sound, i can ear some "claps" using this programs and isnt a clear sound. Can i improve it with a pci sound card like sb audigy?
I doubt it's due to the quality of the sound card from what you are describing (claps). Unless your audio card has flaky drivers, likely you are running into audio output buffer under-runs because the CPU can't produce audio in time for the audio card. So a new audio card probably won't do you any good.
Have a look at any audio configuration screens in your applications and see if you can set things like buffer sizes larger, mix ahead values further, latency values higher, etc. Usually it's not strictly a lack of CPU power that is the problem but the CPU getting blocked out by other OS and apps for very short periods of time that prevents it from producing audio in time when using very small buffers.
