Describe ube sound vs solid state

^I'm sorry, but I don't understand the first sentence.
Headphones are typically an unnatural way of hearing things. Some headphones use signal processing to try and compensate for this unnaturalness.
Old fashioned loudness controls allow for some compensation of the way the human ear perceives sound at unnatural lower volume levels. Which interestingly enough, is further argument as to how the above mentioned graph only reflects human hearing/perception vis-a-vis an accurate stimuli.

I own a fairly good set of cans, they sound good, but I still prefer the two channel magic of a good sound system more.

In many ways headphones are the most natural way to listen to music. I'll tell you why. There are no room anomalies to worry about. There are no speaker cables to worry about. There are no big honking magnets in speakers to hurt the sound. There is no crossover. You usually run Class A all the way. There are no (phase) issues with multiple speaker drivers. No issues with trying to locate the ideal speaker locations. No need for a preamp in many cases. Thus, the sound of headphones can often be more natural than speaker systems in terms of transparency, dynamics, inner dynamics, air and tonality.

Geoffkait, In many ways you are correct. Especially with regard to room anomalies, though with room treatment and room correction, speakers can overcome some of this issue. Most high quality headphones still have cables. Magnets? Some headphones have cross-overs, some speakers don't. Some speakers can be run class A all the way, though I'm not sure just how important that is. Some headphones have multiple drivers, some speakers don't. Some speakers don't have phase issues, (and with regard to this thread, interestingly enough, most of those present a load that tend work better with ss amplification).
Headphones are heard from an unnatural extreme left/right directions, which almost never happens in live music performances. The sound is sent more directly into the inner ear without the outer ear collecting sound in the more natural manner. One of the unnatural outcomes of this is that one often hears the sound as though it's coming from within ones head, missing the natural soundstage qualities of a live performance.
Headphones can offer more precise indication of specific elements of recordings and play back, but ultimately, at least for me, the whole sounds unnatural.

For me, the difference is arrived at by induction rather than deduction. I was never inclined towards tubes or particularly wanted them. But after listening to many different systems over many years I realized the ones that I loved listening to all had tubes--Jadis tubes, Manley tubes, Atmasphere tubes, VAC tubes, and McIntosh tubes. In the mix was Levinson, Goldman, Pass, Classe, and McCormack solid state, which often impressed me with power and authority, but never sent me into a state of "thoughtless joy" with a yearning for it not to end.

If I try to analyze it, the feeling is similar to hearing a chord sequence such as I-IV-V resolve back to the root. There is something so pleasing in that completion that is similar to the feeling from tubes, whereas solid state was more of a matter-of-fact I-IV-V that stopped short of that final completeness. Solid state had more of a Joe Friday "just the facts" while tubes were more of film noir fascination.

So I guess I'm saying that tubes have provided a musical completeness that my brain seems to crave, and this sense of completeness is the difference.