A good set of tubes can be like changing tires on a sports car! LOL. Its the price we pay for those little glorious bottles. I think your about to enter goose bump zone! Tube gear in general is very sturdy and tubes last several thousand hours if you dont leave them on all the time. Good rule : If you plan on listening that day turn the system on then later that night before bed turn it off. Tubes dont like to be turned on and off a lot. Other than that its nice to keep spares for emergency and run your most expensive tubes in the unit. You will know when a tube is going bad when you have no output or one side is noisy all the time. Also, it takes 45 mins at least for things to warm up before you really sit and listen. Have fun :-)
Matt M
Matt M