At least kernel has drivers enabled for all Hifiberry DACs. If you want to use some other DAC besides Hifiberry DAC+ you need to select 'Hifiberry DAC+' from Settings -> System -> Advanced settings -> Audio device. After this edit /boot/config.txt and change dtoverlay=hifiberry-dacplus to load the driver for your DAC (i.e. change it to 'dtoverlay=hifiberry-???'). You shouldn't modify anything else.Hi KonstaT - great work, thank you! I can play now Amazon music hd via hdmi or line out. I also have a digi+ pro HAT that I am trying to enable... I've tried both digi and digi-pro overlays with respective changes in the rpi4-audio script however the card is not seen as Alsa device (dmesg only shows hdmi and line out cards). I have tested the card with raspberry os and it works well. What else can I try? I really appreciate your work and input. Thank you again.