differences between tube and solid state designs


this topic may have been beaten to death.

however, my experience attending ces shows has demonstrated to my eras that the differences between push pull tube and solid state amplifiers sound very similar.

i notice today's tube amps, e.g., contad johnson, audio research, wolcott audio, etc., do not exhibit many of the classic colorations associated with tube designs and sound a lot like solid state, especially with respect to frequency response, i.e., spectral balance.

there may be still be slight audible differences between the 2 formats.

has anyone perceived a narrowing of sonic differences between the two designs and if so if differences are slight, why buy a tube amp.

note, i have deliberately excluded class a and single ended amps, at low wattage, from this discussion. some of them have more of a vintage or classic tube sound, especially relative to bass and treble response.
mrtennis
Any time you have a vacuum, you have a weak link. I think tubes are inherently better to listen to, and replacing every few years and a slightly higher noise floor is a small price to pay for dynamic realism. Considering how noisey the world is these days anyway, it's kind of an academic problem unless you live in the middle of nowehere, and still the hiss is, on my system, unnoticeable except at *very* high volume and with no music playing. So I take the bad with the good.
Biomimetic, I agree with you that the benefits of tubes far outweigh their shortcomings. To this day I have always felt the need to have tubes somewhere in my system. Once done the music becomes more involving & enjoyable. However I have encountered a few solid state designs that are darn good.
On my system there is a more then slight diffrence on how tube amps handle"air in the highs" the soild state just dont get it right. Solid state amps Ive used, threshold 550E, several Large krells (10K plus) Plinius SA250IV, Audio resaerch D350, aragon,ect.
Tube amps are Rogue 120,120M,150, Zeus, hurricanes,Cary V12, Vtl 300,450. ect.
The first thing that comes to mind when thinking about solid state is the Problems in the highend.
I know what you mean about high end... it took me a while to see how tubes also, to my mind, handle the low end better. The hard clipping of solid state can really take you out of the music, the movie, whatever. Soft clipping, and a certain "trueness" in the staging of the bass, aka holography in creating a tone to the room the music is in, I think it has to do with sympathetic chord reproduction, is what I appreciate as much now.
Differences in KT88 vs the KT90.
Anyone wanna take a shot.
I much prefer the 90 over the 88. There is nothing about the 88 tube I like. I like everything about the 90. btw notice how few amps offer the 90.