Highest BUILD quality tube amps?

Allnic. I have 2 pieces, very nice and reliable. 

I got a Jolida tube integrated amplifier about 8 years ago after reading several good reviews. I've been satisfied with it and have had no problems. One of the things that finally convinced me to get it was the fact that there is no plastic on the unit; even the control knobs are metal. The remote control for the unit is also metal and weighs about a pound; the "buttons" on the remote are steel bearings about 1/8" diameter. I figured if they paid that much attention to such a small detail, I would trust them. No regrets.

@erik_squires4:  According to conversations I had with Bill Johnson in the 1970's, those "simple" faceplates were the most difficult and demanding items he sourced for his products. He told me they gave him headaches for weeks and months and that they had to return many of them that did not meet his demanding standards.

Not sure how today's faceplates differ from the old ones; they were a lot of things, but certainly not "simple" to manufacture.

I’m I’m going to throw my hat into the ring as a brand new tuber, and say that the PrimaLuna DiaLogue Premier HP an excellent quality amp that hits way above its $3800 price point, and really sounds excellent. Point to point wiring and a bunch of advanced featUres designed to enhance tube reliability and not drive them to max while still putting out 75 watts in ultralinear mode (switchable on the fly to triode mode). I was actually surprised at how much difference the power amp made in my system!

I have had my Marantz 8b since I bought it in 1964. I also bought the reissue in the 90s. Still working just fine, bother of them. Glorious.