Switching to solid state amp?

Bob, if you're a real tube guy (sounds like it): Class 'A' (lots of heat also) or Hypex nCORE-loaded Class D (Bel Canto, etc) for next to zero heat.

Else, well you'll be missing that 'something'... 

BUT conventional A-B SS like Constellation is getting pretty dang good nowadays!

SS will give the dynamics and grip unavailable to bottles.

All depends what you're aching for to make the change...  ELSE DON'T!

I moved away from tubes after about 15yrs. I was looking for an amp that would keep that midrange magic but have more grip, speed and headroom. I took a chance on an Italian brand called Audiozen that is brand new to the US through Mark Sossa at Well Pleased Audio Vida. I went from tube integrated to hybrid integrated and couldn't be happier. Audiozen also makes the Lysios dual monaural power amp which is currently being reviewed by Srajan of 6moons. Keep an eye out for Audiozen. Amazing stuff and great value.

My use of tubes are seasonal.  I use an Audio Research VT100 (tubed) in the winter when I'm paying for heat in the room anyways.  In the summer I switch to an Audio Research D400 SS amp.  I much prefer the tubes, AR does have a sort of "house Sound" that makes them similar,  on the upper panels of my Infinity IRS Gamma's, but my environmental self doesn't let me heat a room with 500 watts of electricity from the amp and then remove the heat from the room with 1000 watts of A/C.  It makes a good reason to looking forward to the cool weather and shorter days!

You should listen to Ayre offereings

I used a tube amp (845). Due to high tube mortality I decided to move back to solid state camp. It took me a while to find a replacement, an amp that sounds close to what the tube amp had given me. I settled down on Karan amp. I think this the closest.