Good modern tube preamp designs will have years of ZERO maintenance. The small signal tubes make very little heat and have a life expectancy of between 4000 and 10,000 hours.
Also, when it is time to replace the tubes, they are plug and play. If you can change a light bulb, you can replace the tubes in most preamps.
Finally, using tubes in a preamp or line stage has all of the sonic advantages and none of the disadvantages of tubes in a power amp which have to deal with a speaker load.
Also, when it is time to replace the tubes, they are plug and play. If you can change a light bulb, you can replace the tubes in most preamps.
Finally, using tubes in a preamp or line stage has all of the sonic advantages and none of the disadvantages of tubes in a power amp which have to deal with a speaker load.