Is a SUT needed?

There is no substitute for trying one or more in your own system to hear the effect.  Bob of bobsdevices.com sent one of his SKY10 SUTs to me and Wow!  Huge improvement.  My phono stage is cj TEA2MAX, 55 db, using an Ortofon Winfeld with 0.2mV output.

Raul, the single most important aspect of any evaluation of audio equipment in the end must be how the music sounds.  And you consistently neglect to address in your discussions the element of taste.  It is OK to have your preferences, I fully respect that.  You have stated many times that you prefer SS to vacuum tubes.  That is fine.  The problem is that you don't seem to be able to respect others who have a preference for their tubes and SUTs.  Your fervor for your views take on some of the characteristics of a religious fanatic and that is most unpleasant for me and I suspect others.  Once before I drew  an analogy to wine:  Some people prefer Bordeaux, others might prefer a Reisling; I picked two very different styles to make my point: There is no right or  wrong, it is all good.