aplay -l (and alsamixer) returns nothing (not even the other internal audio on the device) but sudo aplay -l lists all 3 and has the RME as default as does sudo alsamixer
This image is the normal Snakeoil install built on Ubuntu server 22.04 so not sure why it would have a permissions issue and even less sure how I might test and fix that..lol :-)
Thanks for your comment and I will explore further.
Cheers, Bob.
Some progress ! From an ssh session I can get output with:
~$ sudo speaker-test -c 2
speaker-test 1.2.4
Playback device is default
Stream parameters are 48000Hz, S16_LE, 2 channels
Using 16 octaves of pink noise
Rate set to 48000Hz (requested 48000Hz)
Buffer size range from 16384 to 16384
Period size range from 32 to 1024
Using max buffer size 16384
Periods = 4
was set period_size = 1024
was set buffer_size = 16384
0 - Front Left
1 - Front Right
Time per period = 5.637026
0 - Front Left
The quest continues.