Those input tubes are critical. BAT has told me matching helps (on other models). I'd by two new matched sections and matched to each other tubes.
Keep your current good tube as your spare. Also, I'd clean the tube pins and sockets with something like Kontak. I light sanding using 400 or 600 grit paper on the pins should help a little to.
Sorry I can't help on the dr vs eb vs pi types.
John
Keep your current good tube as your spare. Also, I'd clean the tube pins and sockets with something like Kontak. I light sanding using 400 or 600 grit paper on the pins should help a little to.
Sorry I can't help on the dr vs eb vs pi types.
John