Theory is a wonderful thing. Even a necessary thing if you are a designer. But theory is only useful if it reliably explains/predicts reality. I used to think the theory of tube pre and SS power seemed to make sense. But I tried just about every SS power amp I could get my hands on before reluctantly trying tube amps. I found a tube amp that not only had a better midrange than the SS amps, but outperformed them in the highs and the bass (and on low impedence Thiel and Martin-Logan speakers). Faster bass and more slam than an SS power amp? It didn't fit the theory, but so what? I have now settled on a tube power amp and a solid state preamp - against all my preconceptions, but in tune with the music.