I've had good luck with JAN/Phillips 6922 tubes but I don't think being military is a guarantee of better sound or longer life.
Do military/industrial tubes sound better than regular ones ?
Or they are usually just more rugged and longer lasting? I am particularly interested in 12AX7 and 12AU7 RCA blackplates from early and late 50s.
They are often double the price, but that would not be my main concern in this case because even regular ones should last for a very long time.
In other words, I would like to have best sounding RCA blackplates in my VAC Avatar SE, and longer lasting would be a bonus.