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?
I think most folks are just leery of buying older equipment because they don't know how well it has been maintained. It's just like buying an older car. Yes, there are great sounding older amps, but some folks fear buying one and having to replace the caps right away. This can run up a good repair bill.

However, I like a lot of the older amps, especially solid state amps, better than more recent offerings. I prefer amps biased into Class A, which was quite popular a couple of decades ago, but not so popular nowadays. My amp turns 20 this year, and sounds great! I just had it back at the factory for service last year, so it's good for another 100,000 miles. :)
I agree with Jmcgrogan.
(Though tube equipment is my preference).
High quality serviceable amplifiers are always a very viable option.
You didn't forget to go around and kick all four little footers before you bought???

Most of my stereo equipment is 10-20 years old. The only components that I've had break on me were bought new, and thankfully under factory warranty. Getting them repaired in a timely manner is another story...
With ERbay it is very much a hit or miss game. In my experience it has more misses. If you see one for sale here or other audio fan websites it is amost always a hit. I you do buy from Ebay never (almost never) buy as is as seen and demand a right of return, if you think something is wrong, not if the seller thinks it works great. If he refuses your terms ignore that one and you will find another. To be fair you should pay shipping and listing fees.
If you got lots of money then just buy cheap and have it professionally refurbished.
I agree with jmcgrogan2,, Its not broke,sounds great, who cares whats better,how much better is the question, you would have to spend alot more now days to get better if you have a very good amp already!,, and on the bright side of things if the amp you have is very,very good, when you do buy another amp, keep the old one, a collecter may give you alot of money for it! cheers!
A 15-20 year old amp should be completely gone over and overhauled imo. Even if it sounds great, it will benefit and sound noticeably better afterward provided you find the right tech which is rare. If his heart's not in it, you likely won't notice anything. If it is, he will have chosen parts very specifically in order to improve and not just maintain it. Well worth the average $400.00 in that case.
Digpix, many of our EE techie members have spoken about aging electronic components numerous times on the Forum. Csontos is right on with his comments.

Certain components degrade over time -- period. Even if a component hasn't failed, it may have drifted from its intended value with age. You didn't mention the amp you had in mind. If the company is still around, you might be able to send it back to the factory for an overhaul.

I own some 30-40 year old Crown amps. Sent both back to the factory. You'd be surprised how many little "this's and that's" were replaced. The cost was very reasonable. The Crown folks explained that there were still some "old head" techs around who knew the old gear like the back of their hands. That's the reason for the quick and reasonably priced overhaul.

Just a suggestion.
One issue on the solid state side is the availability of replacement transistors. Some very good amps used transistors that are becoming or have become unobtainable. However, even with that, if the amp is that good, you could always look for a used/broken one to part out.

The other thing I think about is the precariousness of the "one guy shop" that a lot of our great sounding equipment comes from. Since there is often no succession planning, if something happens to the "one guy" the company may cease to exist. The gang of folks that got into the business of designing/manufacturing high end audio in the 70's, 80's and earlier is starting to get pretty long in the tooth, so when purchasing older amps a consideration is whether there will be anyone around to repair it if needed. Since most of my equipment comes from "one guy" shops, I can only hope that there will be competent technicians available to repair the equipment as long as parts are available. Of course, the other option is to make sure the "one guy" is younger than you are :>}
Yes, have a piece of vintage gear checked out by a technician you trust.
Yes there will always be competent techs. And yes, there will be enough carcasses to cannibalize in ours and the lifetime to come. Just because in addition to the original designers and builders, a large tech fan base will exist for great stuff, which actually is a very good yard stick for eligible candidates. Of which my 3 TNT200's and TNT120 just rebuilt/modded by Roy Esposito are good examples of. I have several other GAS gear done by Mike Bettinger and a local tech. Also a pair of vintage LSR&D Leach Superamp monos rebuilt locally. They are all stellar performers. The key is to trust the technician with the "right" and the best feedback/references. Lots of unwitting customers give good feedback just because it's "working" again. Those techs are a dime a dozen.
Do your homework! Don't be fooled by certain outfits just because they're advertizing here or elseware running prominent businesses. Quite often that is the best disguise. I've been burned this way more than once. Can't name any names where it happened.
"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.
Exactly. It's either ho-hum or an improvement.