In my VAC PA 35.35, I was using "Winged C" and EH Gold Dragons. I swapped out all the tubes at once, the smaller tubes are now NOS Telefunken 12AT7 and 12AU7. The EL34's are Mullard reissue with the Groove Tube label. The change these tubes made was amazing, it transformed this old amp from sounding ok, to an amp that is maybe the best I have owned, and one of the best I have heard.
Best of luck,
Dan
Best of luck,
Dan