Would there be any issue sending a variable level input into the Amp? I’d like to hook up a pre-amp to be able to select among several source components (CD/vinyl/tape), keep the Amp itself at a fixed volume level, and control volume with the pre-amp physical control rather than the Sonos app.

Related to that, does the Amp maintain separate volume levels for the RCA and HDMI inputs? I’d like to hook up a TV directly to the Amp as well; would changing the TV volume effect the volume level that I’d set for the RCA input? In other words, assuming the above pre-amp scenario works, would I need to adjust the Amp volume every time I switched from HDMI to RCA? Or would the Amp remember the last-used RCA volume setting?

Thanks!