New McIntosh amp build quality

I've had a MK IV, MK V and a MK VI in my system. All fabulous amps with equal build quality. 
Personally I preferred the MK IV, which I felt was just a little more tubey than the MK VI. I also liked that the MK IV had attenuators and looked like the 60's MC275's.
The MK VI does have a little bit of a different sound signature - more bass, more detail, but I guess I was so used to my MK IV that I kept it instead.
I bought all of mine used from private sellers with no issues what so ever. 
Only reason I sold it - I run my system as two channel and surround for at least 3-4 hours a night so I decided to go with solid state.
MC601's is what I have now and they're going nowhere. Had I have me room I would have kept the 275 for a secondary system in the future.

"How It’s Made"... McIntosh MC 275 Tube Amp
Seems like a  flimsy build quality. 

https://www.youtube.com/watch?v=wRLn9LzIAtU

Interesting that this thread popped up now.  I just bought an MA-8900 Integrated and when my dealer was installing it (it is part of a complete upgrade of my entire system), they could not get it to handle the switching to pass through mode (I use it to drive L/R speakers in my surround system).  Every time they tried, it would literally lock up and not switch to any input.  After hours of trying everything they could think of, they called McIntosh.  McIntosh is building me a brand new one and working on a firmware update to deal with the switching issue.  My dealer lent me their demo 8900 to use in the meantime and it's working fine.  I think all the technology getting stuffed into audio equipment, much like mobile devices and computers, is doing more harm than good.  

The good news is that the sound is glorious with my vinyl and digital (both Redbook and Hi-Res) music collection.  I'm confident that McIntosh will deliver a perfect replacement that I expect to keep for a long, long time.  

yyman23....do you prefer the sound of the 601’s compared to the 275?

My experience with Mac is limited to a C2200 preamp and an MC2105 amp. While the C2200 was sweet sounding and practical, its build quality is no comparison to the MC2105; in this regard, build quality, they’re in two completely different leagues. The C2200’s meters had an issue that required servicing and in unplugging a pair of leads from the circuit board, the circuit board actually lifted from the frame, so flimsy is it. The MC2105, however, is built like a brick s....house, with a chrome plated, metal frame, rigid circuit boards and hd parts - mine was built in 1975 and still works flawlessly. So, at least in these two examples, there’s a significant difference in build quality between new and old.

I almost forgot my beautiful MR67 tuner (1967), it really is a work of technical art, unsurpassed in quality.

In general, build quality and sound quality are not commensurate, meaning: you can have a poorly built unit, of any brand, that sounds fantastic and/or, you can have an elaborately and well built unit that sounds bad. In other words, just because a unit sounds great doesn’t mean it is qualitatively built.

Build quality ultimately affects longevity!

Ultimately, the ideal is superb build and sound quality all in one!