I am using a RPI B 2 with OSMC as a media player for video and sound content. I have an amp connected via the analog 3.5mm jack output of the pi.
When the audio volume of the pi is relatively low, the audio is disturbed with a crackling noise, a little distortion similar to distant radio stations. The audio only disturbs when played over the analogue output, not via the HDMI. It also disturbs when tried with a headphone.
I have read this problem might be cause by electro-magnetic interference from the power supply, but I have tested with several cables/adapters including some claiming they minimize the interference, so I believe I can exclude that as a problem.
Another solution I found was setting
disable_audio_dither=1 in /boot/config.txt. This, however, dit not make the difference.
I also found the suggestion to use a HDMI audio extractor or a USB audio adapter, but I am not sure what the audio quality of one of these methods would be and what features I have to look for when buying one.
Can you help me creating a clean sound output? Many thanks in advance.