@sjackso1 "...I find the 6sn7 board with my Tung-Sol 6sn7GTB provides a good soundstage and a rich tone that you can listen to for hours. I swap different boards and tubes. Presently I am using a board with 2 Telefunken 12au7 tubes. I really enjoy the outstanding sound and flexibility this preamp provides."
This is an interesting ability to compare the two tube types using the same preamp.
Are you utilizing new "re-issue" TS 6SN7GTBs to compare to vintage Telefunken 12au7s?