I've been struggling with this for an entire day to no avail. Nothing I tried helped. Here's the situation:
- the DAC (FiiO Olympus E10) works flawlessly in Windows.
- in Ubuntu I get random crackling and popping during playback akin to an old vinyl.
- the onboard sound works fine, it's only with the DAC.
- this only happens on my desktop (both in Ubuntu 13.04 and Xubuntu 14.04).
- on my laptop (Ubuntu 13.04) there is no such issue, the DAC just works.
- the intensity of the crackling varies - sometimes it's not instantly noticeable.
- occasionally it gets extremely bad when I scroll with the mouse.
- the issue seems to go away completely when I run "stress -c 4".
I tried many things:
- nothing I did to alsa or pulseaudio settings had an effect on it, and I've tried everything I could find on the internet that could be related to the problem.
- I tried different USB slots and even removed all other USB devices, no effect.
- I disabled cpu power saving options in bios, no effect.
- I disabled onboard sound and blacklisted HDMI audio on my video card, making the DAC the only audio device. Didn't help.
Anyone got any idea what could be the problem here? I'm at my wit's end.