A friend of mine worked in the USA repairing (now vintage) tube amplifiers and he would often tell me how beautifully the Mullard EL34 sounded to him - the best he heard at the time, from a client's amplifier, but that was in the 19080s. I was sure the Mullard EL34 were long gone, I would be seriously suspicious of them appearing on the market now. I'm sure there are some good alternatives from modern production, like the Psvane.
Do NOS Mullard EL34 tubes last much longer than NOS SED (Svetlana) EL34 ?
Well, Mullards are $450 each and SED are $120 each. I need four of them for VAC Avatar SE. For now I got a set of SEDs but for the next set..? Bloody expensive. I really like Mullard long plates 12AX7 for line amp.
Maybe it's not worth it, anyway, maybe I wouldn't hear much of a difference.