Just following up with my listening impressions after further break-in and tube swapping. Amperex 6922 and Telefunken 12AX7 have made my Romulus a virtual match for the sonics of the rest of my system. More liveliness and emphasis on the high frequencies and less bloating in the midrange and upper bass. And it maintains all the analog sonic qualities that I prefer. This is the last stop for me, as I am very pleased.