Thanks again, @David_Snyder!
I have been experimenting and trying to make sense of Devices. This is what I have now:
But I’m not sure whether - in the case of my ParaSound - to use:
- Parasound
- System Output
- Built in Output
and what the implications for sound quality are… obviously I want the best I can get 
.
And - for that matter - how to change Devices for output in Roon; they don’t seem clickable.
If I disable SoundSource by using the ‘No Redirect’ setting - and/or still use SoundSource for all my other sound sources except Roon (which I think is your advice, thanks), would I then use the macOS System Preference Sound pane?
And would the next step to be to fine tune the Device settings for 1, 2, or 3 in Roon’s Settings > Audio?
But which?
In this post I read that Built-in Output (3 above) results in better sound quality than System Output (2 above); but isn’t that using the Mac’s internal/low quality DAC?
Thanks to anyone who can help me through this little maze, please… I’m confused. But I know I can get there