It always depends on the particulars of a given amp/preamp, the tubes used, and the rest of the system, etc. Plus it’s subjective, but in general I’ve found tubes to have a more holographic sense of space, textured harmonics, and realism that I haven't found with the SS amps I can afford, while solid state amps definitely tend to have more bass slam due to their greater damping factor.
After years of owning both, I thought I had settled on full tubes, but added an SS amp in bi-amp setup to power the woofers a while back....best of both worlds.
The difference between tubes and solid state that I am finding
I'm still a newbie when it comes to tubes. I have had the McIntosh C12000 preamp (with Moon 861, Eversolo A8, and Focal Sopra n1s) for awhile now. It is very enjoyable. I noticed when switch between Tube amp and Solid state mode the difference is very subtle. But when I do focus on it, I notice:
Tube sound: More open with a slight blossom sound. Maybe slightly more holographic. A pretty sound.
Solid State sound: More exact. Instruments seem more there and defined. More in my face. Bass hits harder to. But not as open and airy.
As far as brightness, I wouldn't say ether one is more softer than the other... the brightness seems same on both.
Am I correct in this is how the differences between the tube/states differ?
I really enjoy both modes.... but I think the solid state one gets me a little more excited.