First off, this is not a Volumio problem. One of my Volumio systems is connected to an old Tivoli Model One radio via the AUX connector. The sound is great, except for a prominent buzz. I tried upgrading the RCA to 3.5mm jack cable and swapped the (official) Pi PSU - no improvement. Any tips?
Pi 3B, Volumio 3.182, HiFiBerry DAC+ Pro.