I have check out the schematic of the stealth 60 and the red board. From my personal experience, the pentode gain stage has been vastly underrated. It was really nice to see a 6SJ7 and 6SL7 being used. There is something special in the sound with a pentode, the midrange seems very "fleshed" out. Anyways, I am not challenging the choice of the 6SL7, but can a 6SN7 being used, and/or a current source phase splitter. My guess, is a current source is not easily be directly coupled, and the 6SN7 may not have enough gain.
I just want to know the decision made by the experts, and hopefully I can learn something.
P.S. Toronto is a great city !!! I used to visit it once a year.