Tube sound Comes, mainly, from? Pre or Power?

This might be the world champion of reviving an old thread, since this one is 13 years old this year. I didn’t bother to reread the entire thing, but what most people think of as the tube sound in my mind has to do with the output transformer of tube amplifiers, which even if built to the limits of current technology will always be the limiting factor and at the most distortion of any element in a tube based signal path. Tubes themselves are wide band and very low distortion. Output transformers are imperfect and add all that cuddly warmth etc. that tube aficionados like so well. That is why I have been using output transformer-less tube amplifiers for my entire audio lifespan.

My phono and pre have output transformers. So mea culpa - I like speed of proper output transformer. In both amorphous cores and in phono it's silver wired. If to add sweeties into the mix easiest way is to change output tube in phono. If to speak about modern technologies - winding machines advanced a lot compared with the old ones, there are a lot of new core materials. So in general it should be more easy to wind proper transformer.

I think I was a bit too strong in my anti-transformer statement above. I have heard many transformer coupled tube amplifiers that sound excellent. I will just leave it at that. I do apologize to those who use such amplifiers. But my post was really in defensive response to those who would say that tubes per se add distortions and colorations.

I find that the amp makes MUCH more of a difference in sound than any other electronic component.  In the case of tube amps, there is such a wide range of sound from different topology, tube types, models, etc., that the sound can be extremely wide ranging, with many sounding less appealing, to me, than solid state amps.  Among tube amps, I've heard great sound from all types of amps--single ended triode, pushpull tetrode/pentode, and output transformerless (OTL) amps so I do not think any one particular type is the best--the specific implementation and voicing matters.  The OTL I particularly liked is a unique custom built amp, my favorite pushpull amp is a Western Electric 59B, and my favorite single-ended triode is probably the Audio Note Gaku-On.  I suspect that the ZOTL amp can be good too, although I did not like the specific voicing of the two brands I heard (I liked the Berning, but, it is not among my favorites).  

The favorite among the amps I own is a pushpull amp running Western Electric 349 output tubes.  I am also a big fan of pushpull amps running 6L6 or 350B tubes.  I also own, and like, the parallel 2a3 amp from Audio Note (Kageki).  

I always feel uncomfortable discussing amplifier types without reference to the speaker. In my opinion, in assembling a good system, one must start with the speakers. Once you have chosen the speakers, then is the time to consider what type of amp is best for driving those speakers. For one glaring bad example, you would not choose a low power SET amplifier to drive say a Wilson audio multi way lower efficiency low impedance speaker. I start out by my lifelong preference for electrostatic speakers with no crossover. For that type of speaker to my ears and in all my years of experimentation, there is no doubt that an OTL amplifier is best. Atmasphere  happens to make the best sounding 0TL amplifiers in my experience. So that’s that. A step up from driving an ESL  through its built in audio step up transformer from an OTL amplifier would be direct drive. In this case the tubes are hooked directly to the panel with no step down transformer in the path. That is a rare situation, and that is why I bought and also listen to the Beveridge 2SW speaker system which is directly driven from its  in built amplifiers.