Some update one or two months ago (I didn't notice the issue right away) is probably responsible for the ocassional stuttering of the sound in VLC and Amarok that I have ever since. The issue seems to occur more often when there is a lot of load on the CPU. It seems to be very similar to https://bbs.archlinux.org/viewtopic.php?pid=1261105 , which I've read, but it doesn't seem to solve my problem. At least, I don't know what to make of the hexdump stuff, which is described as the final solution there.
I'd be happy if anyone could point me in the right direction or even help me solving the issue. Thanks!