I got a sound card as I was getting dropouts, (see my thread on dropouts) but it didn't fix the issue. I was trying different settings with ASRock A tuning (asrock motherboard) and found the standard setting gave me drop outs, performance setting instantly killed the audio engine and power saving setting everything is working. I ran the audio tutorial file through 2 times without a dropout. Soundcloud, youtube and Itunes are playing without dropouts.