In my experience, the stock tubes are better than any of the 6volt tubes I tried including the Tungsrams, and better than Radiotechniques 12au7. The Psvanes have a cleaner midrange that is more balanced with with the highs.
PS Audio BHK lacking..
I bought a used PS Audio BHK preamp to replace my Rotel. It sounds thin with no depth & bass compared to my Rotel so I let it run for over an hour with no change. I'm new to tubes so I'm looking for ideas. New tubes or what?