Have been experiencing static noise from the analog output on my Raspberry Pi for some time. Tested several different power sources and it came to a point where I wasn't sure if the noise has always been present or not. In the end I got a HifiBerry Dac+ and some decent cables and the issue went away. The installation was really easy and well documented in the HifiBerry Knowledge base. In the video above you can see the difference, I very much recommend this!