Crackling buzzing noise on HP Spectre when playing sound

I got the HP Spectre at the Build conference this year and I love it but I’ve been seriously annoyed by this crackling buzzing noise when listening to music or anything really.

I thought it was only my HP but a lot of people complain on the HP Support Forum about this issue. They tried anything and everything from re-installing the OS, audio driver, returning the notebook three times and so on.

The issue is solved by simply unplugging the AC power adapter. Seriously HP?!