Wait a second. You had the amp since 1973 and never bothered to service them for 27 years (eg, at minimum recapping). Now your complaining the amp failed? The fault is on you and not the amplifier. Why would you post something that happened to you in 17 years ago? And why would you compare an affordable no longer in production SS amp to a pricey macintosh? I don't get the point of your post.
phase linear amplifiers
back in the early 70's I bought a phase linear 400 amp. never will buy phase linear again. in 2000. it fried 3 of my speakers. later on I read they they were known to do this. they were cheap money for the big watts but were not well designed well to work under stress. I have McIntosh now. no worrys!