If those tubes burn out to quickly there must be a problem with that tuner. Preamp tubes should last for years!
Small signal tubes like a 12AX7 or 6922 will work well on average for about 10,000 hours. If you leave your equipment on 24 hours a day, well you do the math: There are 8,760 hours in a year. So when does a tube go bad? It depends on how picky you are.
Here is a shootout on the best vintage FM tuners!
https://fmtunerinfo.com/shootouts.html
Small signal tubes like a 12AX7 or 6922 will work well on average for about 10,000 hours. If you leave your equipment on 24 hours a day, well you do the math: There are 8,760 hours in a year. So when does a tube go bad? It depends on how picky you are.
Here is a shootout on the best vintage FM tuners!
https://fmtunerinfo.com/shootouts.html