Luxman leaves me wanting

Are you streaming with Roon? If so try applying some eq using the DSP functionality. If you are not, give Roon a try just for that. Easy fix once you get it right compared to the hifi merry go round especially once you already have good stuff that maybe just needs a little tweaking to get right.

If you want to be really brave you can also do Room correction with Roon + Room Eq Wizard freeware and a good quality usb mic to a laptop computer. That will really help set things right.

All rooms affect the sound greatly and you don’t know how good fixing that can be until you actually do it. Practically, I would always recommend do Room Correction first to set the table straight then decide if any changes or upgrades are still needed. Chances are you will be very pleasantly surprised what any good quality system can do once room acoustics are addressed properly. 

If you want richer, I recommend Pass Labs.  I have both L590-AX and INT-25 and I get what you mean about the Luxman.  The Pass definitely has a meatier sound with more "in the room" imaging and presence.  I had an LTA Z10 and found it comparatively thin sounding in the end, though I liked the transparency and overall sound.

Devore and Luxman is not a synergistic combination.  
IMO Luxman does well with hard to drive, warm sounding speakers that are midrange focused. With Devore speakers, tubes are the better choice. 

+1 on Pass recommendation.  Int60 should be a nice pairing. 

As I understand it LTA does not have the meat on the bone tube sound you are seeking.