On the LTA website it mentions that they drive the tubes with 1/3 of the amount of current that typical tube amps use which is part of the recommendation.
Also many believe that tube life is shortened because of multiple power up / power down cycles. Consider the physics of a cycle- abrupt current and heat to a cold tube and tube glass, thermal expansion differences between materials- e.g. glass and different metals and pins that are expected to hold a mechanical vacuum to survive. Running at temperature and maximum thermally expanded state for many hours then a rapid cool down / thermal shrink after power down. This happens every power up / run/ and power down. Thermally and mechanically stressful to the tube elements and glass.
Most tubes do seem to fail at startup as opposed to failing gracefully while running- similar to an incandescent light bulb.
I would consider leaving them on with an LTA product and see how it goes.
Also many believe that tube life is shortened because of multiple power up / power down cycles. Consider the physics of a cycle- abrupt current and heat to a cold tube and tube glass, thermal expansion differences between materials- e.g. glass and different metals and pins that are expected to hold a mechanical vacuum to survive. Running at temperature and maximum thermally expanded state for many hours then a rapid cool down / thermal shrink after power down. This happens every power up / run/ and power down. Thermally and mechanically stressful to the tube elements and glass.
Most tubes do seem to fail at startup as opposed to failing gracefully while running- similar to an incandescent light bulb.
I would consider leaving them on with an LTA product and see how it goes.