Where to insert tubes while running a Luxman SS integrated


I've recently upgraded my integrated amplifier from a Cambridge CXA81 to a Luxman l-507uxii.  The Cambridge is definitely not bad for its price, but the Luxman is a different animal and is making me want to upgrade everything else in my system.  Which brings me to my point of discussion: I'd like to insert tubes somewhere in my system to get some additional warmth and a more holographic soundstage.  Would adding a tube preamp and running the Luxman as only a power amp be best to do this, or would it be better to get a tube dac for my digital, and separately, a tube phono stage for my vinyl?

syr1990
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Thanks for your dac suggestions @jjss49. Yes, the Luxman R3 combo is very revealing, including of recordings with harsh treble. I was surprised that the highs are a bit smoother than with the previous amp (the CXA81), though. 

My L-505uxii with a Herron 360 pre was a surprisingly stark match.  A lot of the Luxman magic seems to be in the pre.  I suggest try before you buy.