Check out Weston Acoustics amplifiers. Australian made in a Melbourne suburb and very highly regarded within the Stereonet community. Earle even winds his own transformers and does all the cabinetry as well. I have owned the Troubadour which is a 20-30 watt integrated amp, depending on what valves are in it, for 8 years now and have had no issues at all. He also makes mono-blocks.
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?