Very low audio over analogue out / headphone jack

I have RPi2 with LE. All works very well when having it connected via HDMI. However, when connecting it to my tv/amp over analogue out (or whatever the headphone jack is called?), the audio volume is very low and I need to crank up the volume to almost maximum to be heard. Obviously, this is not a viable solution.

Any idea whether and how I can fix this. I tried all kind of settings, but not successful. Debug log attached.

http://sprunge.us/WGRL