life span/failure rate of filter capacitors?

I seem to recall reading that thread or another elsewhere with Cary amps of that vintage. I ran Cary SLM100 monoblocks back in day, had the well known issues with Jensen coupling caps, also had issues with maintaining bias on power tubes and occasional fuse blowing, I'd replace those caps just to be safe, lots of inrush current with your amp, stresses the caps.

Before 2000 I would have said that generally 20 years for filter caps kept warm.

I think newer caps should do better, around 30, especially if high temp.

Caps may bulge or leak before complete failure, or get unusually hit compared to their peers.

Caps do sometimes go through poor quality issues which may cause premature faiure.

If in doubt have it recapped with the highest possible temperature ratings. More expensive, but higher longevity.

Electrolytic cap lifespan is unpredictable! My Sumo Andromeda is still going strong while my BEL 1001 and GAS Son need new caps.

should do basic maintenance after 15-20 years, replace all of them, have factory give a overlook at everything.

i was told after about 19-20 years, start looking for a warranty, or i mean the company who built the amp.