Using two Luxman integrated amplifiers together

I think you should do this all as a personal experiment because I'm pretty sure you'd learn more than anyone here.

There aren't really downsides, but I do find the SS preamp stage in Luxman integrated amps to be excellent performers, so I'd be curious to know how you compare the two preamps driving the same amplifier.  What might also be fun is if you had speakers to biamp as well.

I don't see a problem, plus you could try it both ways (SS pre/tube power - tube pre/SS power).

When using the tube preamp section be certain to turn the tube amp on first before turning the SS amp on (reverse this when powering down the units).

The combo's should not waste much, if any, energy VS using them as stand alone units as you will only be using the power amp section of one unit @ a time.

DeKay

As the others say try it you own both components so nothing to lose. Curios myself which combo will sound best.