The continuing saga of enlightenment. I checked config.txt, it was empty so I downloaded the latest image of jessie, installed that and ran the drum hat installation script. It worked just fine on both HDMI and the 3.5mm output. So far so good.
Now for the PHAT DAC. I soldered the header onto PHAT DAC. Not all the pins, pins 2,6,12,35 and 40. I removed the Drum Hat and fitted the PHAT DAC (yes, I did shut down and power off first).
Before running the script I checked config.txt, the last line was dtparam=audio=on
I ran the script, it all seemed to go well. When it was done I rebooted and waited for glorious sound. Nothing. I checked config.txt, now I had
aplay -l, it showed just the new device. I rebooted again, still nothing. The volume is turned up, honest.
I uncommented the dtparam line, rebooted, I got all the original stuff back as well as the hifiberry stuff when I ran
aplay -l and I could get sound from the hdmi and 3.5mm but not the PHAT DAC.
So, where to from here? All help and suggestions will be gratefully received.