Tubes burn out a lot less than most people think. I’ve got working tubes that are 60 years old and in active use. I have a tube tester and they do fail, but not ever 1-2 years like some think is a needed replacement cycle.
tube’s failure is such that if they survive the infant fatality, they will be more robust and reliable than transistor. The transmitters on Voyager probes have been going for 47 years. Those tube were pre-screened ones that survived from infant fatality. It’s like sea turtle, if they survive first few years in the wild, they will a very long lifespan.
Yup. Lots of ones in my 4 Hammond organs are original. My Model M is from approximately 1950!
L. Hammond is right up there with the great geniuses of all time.