You appear to accept that higher levels of distortion, reduced top end, lack of bass etc. that are inherent in tube amplifiers, actually improves the sound. I don't!
Please come back to the 21st century.
And no one wanting to analyze the sound of tubes seriously should say that people state that higher levels of distortion, reduced top end, lack of bass etc. that are inherent in some tube amplifiers, actually improves the sound. What some of them wisely say is that, in spite of these bad characteristics they sound great, and in some aspects better than the better measuring units!