20 Year Old Amplifiers compared to 2017

@cheeg,
Ive always heard such good things about the older McCormack DNA amps, as you described above.
 
The OP specified some higher end amps from 20 years prior, but I will say that right now I am listening to a Luxman R-113 35w SS receiver built 25 years ago in 1993, driving a pair of Zu Audio Omen bookshelves, 16 0hm.
Sounds great! 

I mean, the Luxman only cost me $65 at the local record store, but it is similar to Naim to my ear, but a bit more even keel (less PRAT-ish). 

oh, and what about Naim amps/integrated? they have a cult following going back to the 70's, and still traded heavily on the used market, but may need recapping.

Lets not forget the Carver challenge to Stereophile Magazine (J Gordon Holt) that he could make a $700.00 amplifier (specifically his model 1.0) sound indistinguishable from any high end amp of their choice and he succeeded in doing so.

Well... he was within 30 db if I recall that right.

I’ve always been curious about the definition of a "well designed" amp. As if there is a universal design that is appropriate for all circumstances. Most audio companies build to a specific market audience at a specific price point.

For the purpose of the millions of people out there who love listening to music on their iphones, that amp is well designed. It fits in your pocket, doesn’t kill the battery and will play music without committing too many sins that one can detect with the supplied earbuds.

I’ve heard lots of engineers state unequivocally that all well designed amps sound the same. My experience is the engineers who say this do not work designing high-end audio amps.

I suspect they’re hearkening back to something they learned at school about a theoretical ideal; a black-box ideal where components have perfect specs, are operated within parameter in a perfectly stable environment.

The problem in the real world is that part ratings vary significantly from specs. Electrolytic caps within the same production vary by as much as 20%; transistor ratings can vary by as much as 100%. Tube ratings can vary by even more!

Designing an amplifier that can be manufactured using imperfect parts that consistently achieves low distortion and high linearity appears to be pretty difficult.

I recently replaced mysuperb Mcintosh MC30’s with a Pass F5 Turbo Version 2 that I built myself. Let me first say that the MC30’s were completely restored by me using modern high quality parts. I wager to say they sound better than they did when new. Simply superb.

The F5t is different. I’m not going to say better because at this level "better" is subjective. To my ears, at normal listening levels with my Klipsch Cornwall 3’s the sound is more dynamic, the background is quieter and the micro detail is much improved.

I don’t think anyone would argue that either of these amps are poorly designed. They both have legendary reputations and make people happy. But they sound very different as they should since they employ radically different topologies.

They’re both well designed; differently designed and the result is, unsurprisingly, different.