I gave you the thread on CAPs in power supplies and circuits. Read it. Unless the caps are real bad, it isn't a "major" thing at all as they age. The "rant" is easy to "listen" to. So many want to read till they agree with the "words" and never listen.
How many of you even HAVE an amp that is thirty years old to listen to? Most here that do have a twenty to thirty year old amp seem to say the experience is like mine which is not too bad. And, Like I said for the third time, big caps do age in the power supply and are easy to change out. The cans face "up" with the leads on top, usually, so inspection is easy. If you have a twenty or thirty year old amp you want to keep, simply change them out.
I do have an older amp, and it runs fine and the caps are physically sound (no bulging, leaking. ETC). No, the caps won't test the same as new, but the amp is far from "major" different to newer reference equipment relative to the APT one's ability in the first place. The supply can still deliver OK bass transients and the amp is very quiet.
My "one" amp is FULL of large caps, so the statistics are in the favor of caps doing well over twenty plus years if they are of good quality. If it was ONE cap it would match you smoker anlogy. I have statistics on several in the same amp under the same stresses. This is called a large sample population. HEAT is the major enemy of electronic parts. A 10C difference in service temperatures can add an easy ten years to a components life. And, this isn't the ONLY unit I have that is older and working fine, and they have caps, too. So say bye-bye to the lone cigarette man.
When is an amp "true" to you? Since you don't accept that an older amp can sound fine, not like new, there is no truth other than what you read. When do you "decide" your amp is all of a sudden "MAJOR" different? It just all of a sudden goes "major" does it? Do you have an identical new amp that never ages to reference it to? You'll need one as the sound quality does diminishes slowly.
I find it interesting that so many reference what we "read" and not so much, if any, on what we hear. I'm as sober as can be and SS amplifiers and lesser audio circuits age very well with good quality parts. They don't "massively" change except for total loss / leakage.
I have NEVER had a SS unit die from capacitor failures. Transistors, yes. Diodes, yes. Resistors, yes. These parts have been replaced and all upstream and downstream components have been fine (except failed output transistors, they over current lots of parts). It might be fairly argued when more than one component fails, it's hard to point to the one that started it all. But, Phase Linear 400 amplifiers in the day blew outputs all the time and I NEVER saw the capacitors replaced.
So again, someone decides my "position" that power supply caps don't matter is simply silly. Sure they matter, but much less so over time than people want to "read" verses "hear". Most good supplies are well over the design spec of their peak current ratings to provide headroom. As the caps age, the headroom does diminish. But it is still "servicably" good after decades of service to sound nice. Most amps run far under their design limits, so transients are still reproduced well.
But, if an amp ages and simply goes "major" all of a sudden because we simply read that they do at some point in time, than many people will be happy to buy these amplifiers!
The near end of "major" is fifteen years and the far end of "major" is thirty years. Your service temps are far more important to service life than any other variable except the quality of the part. My ears say so, and so does inspection of my equipment. You can't be any more sober than that.
