Lifespan of Power amps


What is a reasonable amount of time a power amp should perform without trouble, or need replaced? If kept in good, clean condition I'm guessing 20-25 years, is this correct? I have an 18 year old power amp and am just trying to figure how long it will be until I will need a new one. Does anyone think the technology is the same today as it would have been 18 years ago for amplifiers?
fruff1976
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?