I think the term ultra linear is marketing in nature and I dare say most people have no clue what they’re buying when they do.
But ultra linear does drift more toward solid state and isn’t that what we’re really saying overall after all
I am not sure whether you are just troll posting, but assuming that you are not, do you also feel that, for instance, single ended triode is also "marketing in nature"?
the differences between modes of operation which on this amplifier tend to be switchable so easily which always raises skepticism
Are you also skeptical about the sonic differences between different vacuum tubes because it is quite easy to swap them out? Adjustable feedback? For that matter, do you believe that possibly the whole concept of vacuum tube gear is also a marketing ploy, and underneath it all lies solid state circuitry?
Just curious.