Highest BUILD quality tube amps?


Not so much with sound...lots of ways to fine tune thru tube rolling, etc. I'm just curious which tube amps are built to last for many years with the least amount of repairs. I know Mcintosh comes to mind for longevity. I was snooping around on the web and Air Tight seems to be built like a tank and I've never read any poor repair histories. Luxman same thing. Any others come to mind?
aberyclark
Air Tight here,

ATE2 preamp for 11 years now. Nothing to fix until now. Works like a charm 
ATM3 amps for 23 years. Only one timer (starting tempo for protecting the tubes) to fix 3 years ago. 

And wonderfull music !

Thank you Miura San and Respect.
Bdp24, the preamp,monoblocs,and dac from Ear are great!!! Beautifull,natural and holographic sound.
i have the preamp Audio Note M5 and poweramp :GamuT D200
Kronzilla or for that matter any of KR Audio's tube amps out of Prague has been my favourite for years(currently got 3 pcs.). Build quality and sound is our of this world. May not be the prettiest around but they do for sure stand out in every other aspect.
My vote is for Decware!! I bought mine about 15 years ago and have never had a problem. Sound is fantastic!!! Great people.
Printed circuit boards comes in different ratings, most common is FR4, but there are others, including some laminated on metal. It would be possible to have a poweramp with a PCB and have chassis mounted tube sockets with wired connections to a PCB. Suitable slots can be routed in the PCB for higher voltage tolerance, as is commonly done in AC line power supplies and high voltage circuits in CFL tubes.
What fails in tube amps?
Overvoltage and overtemp. Electrolytic caps comes with so many hours of load life specified for a max temp. Metal film resistors can degrade over time with too much voltage for their spec. The degrading can take years and results in a noisy amp. 
Wirewound resistors don't do this.
Tubes degrade over time but may last a very long time, longer than electrolytic caps. Film caps can break too, causing tubes to loose bias and overheat.
PCBs as stated before, turn brown and ugly, oveheating solderjoints loosening them up making them noisy.
Connectors and pots are common culprits. 
Many amps do not have indiviual bias pots for power tubes, but that can be added.  Unless of course it is a selfbiased tube, which not so efficient, and not much used in high end amps.
Solid state components can also take a hit from adverse operating conditions.
Don't be afraid of tube amps.