The Raspberry Pi's audio output (which btw is not terribly high quality) is referenced to the Pi's ground; that's why it works better when the amplifier's ground voltage is close to the Pi's. So I'd suggest going back to the wiring that worked originally.
(Strictly, you'll still have a ground loop since both the audio lead and the ground wire could carry current. Having said that, I wouldn't try to ground the amplifier through the audio jack alone! Just keep the wires neat and parallel)
It might be an idea to power the amp from the Pi header as well; or even remove the USB-C connector and centralize all power connections at the 5V/GND pins on the Pi header. But if you do this, take care, as a wrong connection could destroy the Pi.
(Strictly, you'll still have a ground loop since both the audio lead and the ground wire could carry current. Having said that, I wouldn't try to ground the amplifier through the audio jack alone! Just keep the wires neat and parallel)
It might be an idea to power the amp from the Pi header as well; or even remove the USB-C connector and centralize all power connections at the 5V/GND pins on the Pi header. But if you do this, take care, as a wrong connection could destroy the Pi.
Statistics: Posted by njh — Fri Oct 18, 2024 11:52 am