TRRS analog audio output glitches crakles

bodtx · Published in 2018-9-11 05:45:31

Edited by bodtx at 2018-9-11 05:47

Hi when I use the orangepi PC plus TRRS audio output, I have some glitches which are linked to the video mouvment.
I've tested the connectionbetween ground and video and it seems that on the left ground pin there is a natural link with video output (50 ohms), is this normal?
my cable is a 4 pole TRRS. I even test audio with cable directly plug on soldering but same result.

How could I get a clean audio output?

note that the hdmi audio output is clean.
and my speaker system is clean if I plug it on a MP3 player.

bodtx · Published in 2018-9-13 03:11:35

OK i've figured out. It was a problem of background loop https://en.m.wikipedia.org/wiki/Ground_l...ectricity) Amp and opi were on the same power source. There are many solution but the cheaper and easiest to me was to power the amp (pam8403) with it's own 5v power supply.