Why do tube amps often subjectively sound more powerful than SS ?

When I bought some Alexia 1 a couple years ago, I took my Audio Research REF 75SE with me to pick up the speakers and to listen to them with my amp.  There was much written about those speakers being hard on amps due to the impedance dips.  That guy had a McIntosh MC452 so we compared his 450 solid states wpc to my 75 tube wpc.  We did not have to adjust the preamp volume...they had the same output volume and the REF 75 sounded better to both of us.  

So when I got the Bryston amplifier, I thought, since it was more powerful, put on really powerful music that will take advantage of it like the Conan soundtrack.

 

I put in the Bryston, cranked it up and…huh? Where was that power?

Why did it actually sound thinner?

Less impactful?

Man, I love that soundtrack. And film.
Yeah, another way I can put my experience with various amps - push pull tube amps tend to sound "good to the last drop". I listen loud and I’ve pushed hard on some vintage PP tube amps in the 20 - 35 Watts / ch range. Until you hit hard clipping, they sound amazing (euphonic) all the way through. Sweet, fat tone.

With solid-state there’s more of a phenomenon like: when you crank it up, you start hearing stuff presented in a way that makes you want to back down the volume again. This can occur even when theres’ still AMPLE power reserves left before approaching hard clipping limits. With tubes, you may keep wanting to crank it up until you actually hit hard clipping.

Probably due to a combination various factors - like harmonic distortion spectrum (which Ralph has educated many of us on), and possibly some dynamic compression with tubes (as another poster mentioned) that can actually work toward the presentation’s favor in some instances. "Loudness wars" with regards to digital mastering gave dynamic compression a bad name, but it’s not all bad.

@mulveling 

yes, that’s been exactly my experience!

I have sensitive ears, And I have always found that my tube amplifiers give a sense of ease and relaxation, So that I can crank the sound much higher and still enjoy it.  Whereas when I have a solid-state amp, I find myself turning the volume down.

tube amps typically have much higher current which is more important than watts in several ways (but marketing won't tell you this).

It’s because they’re old school sound, from the days when tubes were all there was.  Some of us were born in the days when SS didn’t sound so good. SS has gotten much better. But then again, so have tubes. Today’s tube amps aren’t your Great-Grandfather’s tube amps.