Hi, just wanted to update this post and say that I’ve managed to get the normal Volumio pi distribution to work with the Raspberry Pi 4b 8gb (revision 1.4).
The problem was the .elf and .dat files in the boot folder of the Volumio were out of date for the Pi4 8gb.
What I had to do was boot up with the beta 64bit RasPi image from https://downloads.raspberrypi.org/raspios_arm64/images/raspios_arm64-2020-05-28/2020-05-27-raspios-buster-arm64.zip
Then update the boot files on the Pi using the usual method from a terminal (or ssh).
For some reason the Pi4 wouldn’t update the files on anything but that 64bit beta image.
Anyway, did that then copied the .elf and .dat files from that raspi 64bit distribution and copied them onto the boot folder of the Volumio distribution’s card, overwriting anything already there, boot up with that and then everything worked perfectly.
Still can’t get the screen working on the Pirate Audio LineOut DAC but it is at least outputting sound so all is good.
Thanks for the help. The debian buster beta also worked well btw but nice to be using the default distribution now.