"If it ain't broke don't fix it." I have owned several amplifiers from the 1960s including Marantz 9, Marantz 8B, Scott LK150 and Dynaco amps that were completely original and sounded very nice. I also own amplifers from the mid to late 1970s also completely original that will give many current day amplifiers a run for their money in terms of coherence, soundstage, tonal balance and clarity. These amplifiers have all been checked out by my tech and they meet specs.
Amplifier's age
I see posts about an amplifier's age and how it's getting long in the tooth. What does that mean? If you maintain your equipment, caps etc., it's well made to begin with, it doesn't use rare transistors and such what difference does it make? Maybe a new amp sounds better, maybe it doesn't. I see amps especially SS McIntosh amps that were made back at the dawn of transistor technology still plugging along. Some tube amps are 50-60 years old. Is it because we always have to find the next thing?