Hi Jay,
Yes very much is subjective in audio, whether one likes a warmer sound, or so forth. But there are other attributes of music that, although subjectively discerned, just about *everyone* would agree is better. A perfect example are the details in the improved sound quality Mike describes with his BAT preamp.
Double blind studies comparing one amp or the other, I dare say, involve unfamiliar source materials, unfamiliar components, in unfamiliar rooms. In other words, the acoustic memory we have which is so important in evaluation and which takes much time develop, is removed from the equation. That is a shame, and that is why such studies should not be taken at face value.
For sure I would believe Mike's well considered analysis over a dozen such fundamentally flawed 'controlled' studies any day.
The question, as Mike has raised, it what exactly is causing such an improvement in sound quality. It may not be tubes per se (as he pointed out), it could be something else in the way the preamp operates.
I just took at peek and see that BAT has a new solid state version of the preamp. I would guess it's as good as the BAT tube preamp that Mike has, without being a space heater:
http://www.musicdirect.com/p-350-bat...te-preamp.aspx
And hey, it's only $8000
Mark