Can you do anything to make power tubes last longer ?

I’ve always liked the RCA 12au7 black plates. I remember discussing them on another thread with you and Mulveling. I’m currently using RCA 5816A black plates as a driver in one of my amps. They’re a little more refined and warmer than the 12au7 and although I’ve never used them in combination with Mullards EL34 I think they would compliment the Mullards nicely.  Something else to spend your money on if/when you get the itch 🤑

@inna congrats on finding the Mullards at hopefully not too an outrageous price. I’m sure you’ll be very happy you did. I had similar experiences, though different amps but the same tubes, and found that the SED never gave me as good an experience as true Mullards. Ralph brings up a very good point of warming up the tubes slowly at the outset. It’s probably (at least one of) the reason he builds his amps the way he does.