I posted this is a fix but I wasn’t sure because I’d only tried it the once. However, this weekend I went away so turned off the Raspberry Pi. Came back and it wouldn’t boot up again. I’d had a new class 10 SD card delivered (was using 4 previously) so figured I’d start again.
Installed, mounted and tried to play a flac file. I had the annoying pops and clicks that I had last time I installed. So despite some posts suggesting otherwise, I formatted and re-installed, then ran the following code after first boot:
sudo apt-get update sudo apt-get install binutils sudo apt-get install rpi-update sudo rpi-update
Mounted, played flac files. Works perfectly. So it’s definitely fixes things for me - I’m using UD110v2 DAC.