Tube sound is not about warmth. It's about correct presentation.

...for those of us with 'aged' hearing, 'organic high frequency roll-off', one can have all the warmth one can stand and then some...

Adding my aids adds an interesting conundrum:

Would the digital items in my ears effect my realization of 'warmth' from a totally A system, represented front to drivers considered to be 'A friendly'?

Since I'm SS from front to amp, and of no pretense of whether or not my choice of speakers would have any....'preference' in their presentation....?

I occasionally think 'warmth' is the F temperature of the studio or hall of the recording.....but I'm just kidding about that....*s*

I can relate to @mahgister's comment of prejudice, but feel it's more of a 'preference'...🤷‍♂️

Re 'hybrids'....tube pre>ss amp v. ss pre>tube amp....what would seem to occur?

Curious minds out on the limb....😏

@wolf_garcia ...Like that....👍 "Bi-Polar" might be better, but starts a whole different disc-cussion....

...Bi-spherical, we can certainly assume....*L*

(Some researchers have posited that the universe may be an inside-out black hole, which 'splains a lot to me....but I've always thought it's all in ones' head anyhow...)

...but I'm just bent that way....

Correct presentation ? Presentation of music that touches your spirit ? Of course, this would be worked out in individual systems of particular design, physical materials used, and component synergy -- inside eqpt. as well as unit to unit-- as suggested by others here.

With very good SS and tube amp designs we are surely in the realm of subtlety, but I find this to be crucial.

Listening to LP’s with fast, transparent Decca cartridges, Transformer Volume Control and 104dB single driver horns, I hear the very slightly greater separation of instruments and information of SS with a First Watt J2, yet the large bottle glass AD1 tubes in my Yamamoto 4w + 4w SET give very nearly this level of abundant detail, equal or greater soundstage, and fully natural and organic sound. This effects what I seek which is to be immersed in and deeply connected to music.

It seems too obvious to state that the different physical materials of glass and metals of tubes, and the materials of SS devices, will inevitably sound different. Of course, preference for one or the other (or each, for different moods, or programme material) seems in the realm of taste, as for different wines, beers, and all the rest.

Not here to disparage the SS camp,  perhaps our ears and perceptions allow us different avenues to the gratification  of well produced musical reproduction. The Bob Carver interview was enlightening. Never knew of his depth of knowledge as to the auditory process and ability to create amplification that our ears would find appealing. 

Well, there’s Bob Carver’s take, here’s Nelson Pass’ thoughts on the topic (and somewhere here, or another forum, someone shared the actual schematic for the project should someone feel like building a do-it-yourself distortion unit to a SS amp):

https://www.stereophile.com/content/gramophone-dreams-26-nelson-pass-harmonic-distortion