Lifespan of Power amps

It's the capacitors. Caps last around 20 years. If you replace them BEFORE they die/break/explode, you'll have another 20 years.

Agree 100%.

Electrolytic Capacitors are a fact of life in amplifiers, tube or solid state. They last about 20-25 years, which is a sort of half-life, IOW about half of them will be bad in about 20-25 years.

I would add that if you buy an amp that has not been in use for several years then it can increase the risk that a cap will blow up when you first turn it on. If you store expensive gear then I'd suggest plugging it in once every six months to a year.

So other than tubes, capacitors should be the only parts that "wear" out and need replacing (assuming you take good csare of your equipment)?

No- connectors, switches and controls are subject to corrosion and transistors can develop leakage and other issues due to the same. There seems to be no free lunch.

Atmosphere,should I sell my pricey equipment and go back to collecting Martin Acoustic Guitars(lifetime warrantee...."improves with age")? -:)

Best regards

Sirspeedy, the effects of corrosion can be reduced by proper care. The tin plate on a good tube socket for example can reliably last for 30-40 years. OTOH if you store it in the basement or the garage where it can be attacked by humidity or moisture, the life of the connectors and filter capacitors can be really shortened.

If you stored a Martin (never a good thing for a string instrument as you know) it would suffer too. What's the saying? there's no free lunch? no free cigar?