re capping

Somehow this didn't get said, so I'll describe the modes of failure. 

Caps fail in a variety of ways. Their capacitance diminishes or rises. Their equivalent series resistance rises, and they leak DC, otherwise called "leaky" or "electrically leaky". Often a failing cap will exhibit some combination of these symptoms. It's not at all uncommon for a cap to measure higher capacitance, but that usually means it's leaking. Leaking interstage coupling caps will slowly destroy your amp so just because you're not hearing some obvious sign of trouble does not mean there isn't a problem. High ESR is just like putting little resistors in series with the cap and the problems with that are hopefully obvious.

Heat destroys electrolytic caps. That's just a fact. The more heat applied and the longer it's applied has a direct relationship with the life of electrolytic caps. Anyone who says otherwise is a liar. 

@kosst_amojan You seem very sure of your facts. YOUR facts, YOUR truth. What about others’ facts and truths?? 🤔

The Truth is available from the manufacturer.
Sometimes the Truth is optimistic and sometimes not.
Life is predicted based on science and math, but can vary widely due to variation in sub contractor supplied materials.

We once replaced 7 million 85°C/35V electrolytic caps with 105°C/50V version from another manufacturer. All was well for a while until we found that the replacement would fail if the bung was over the -18v rail. The potential sucked out the electrolyte and started fires once the electrolyte reached the positive rail.

Hey, same thing happened to the Quonset hut full of Volkswagen size non oil-filled capacitors the US Navy replaced oil-filled capacitors with on that secret communications project back in the 80s. They exploded. Of course the millions watts might have had something to do with it.  Lesson learned. 🤠

@hifiman5 

There are zero facts that support anything but what I said. I'd be surprised if you've ever looked at a spec sheet in your whole life.