The tubes I'm using are also from 1942 and 1943 - World War II vintage. I wouldn't worry about the age, they built them tough in those days - after all they had to survive warfare inside RADAR units - much tougher than surviving in your preamp! In fact I dropped one from a height of ~6 feet yesterday onto a hardwood floor while swapping among the different brands; not only did it not break, it still works perfectly. Even if it was to break, they're cheap to replace compared to good 6SN7s!
Great to hear someone else is enjoying the 7193s! There is something poetic about using a tube designed for warfare to produce something so beautiful, isn't there?
Great to hear someone else is enjoying the 7193s! There is something poetic about using a tube designed for warfare to produce something so beautiful, isn't there?