Frank, would that change the type of tubes used in the Super PAS 4i from 12AX7's, to 12AT7's or some other tube? Or could the 12AX7's be retained with the upgrade?
Must still have a nice supply of NOS AX7's. aa
Yes, true. I have several nice pairs of 1950's and 1960's RCA's, Mullards, Raytheon Black Plates, Amperex Bugle Boys, Sylvania Baldwins, GE's and a lot of new production 12AX7.
I've had great fun tube rolling and trying to find good match ups with my gear and all the different speakers I have.
I'm very fond of the 1959/1960/1961 Raytheon Black Plates. Sweet tubes!! I also love the 1950's RCA, too!