What is the lifespan of a good SS Amp

I have pair of Meridian active speakers that have astounded me for almost 30 years and the amps have never missed a beat let alone been serviced.
Maybe new caps would be an idea but then they might blow away my good system.
Si

There are too many variables. If properly ventilated, & not continually operated @ rated power, 20 to 30 yrs. isn`t beyond the pale.

Electrolytic caps (the big power supply caps are the primary ones) tend to dry out after 12 - 25 years. Higher operating temps usually result in quicker decline but there are differences among capacitor manufacturers too so it is difficult to generalize. Occasionally you'll see early failure or caps that last beyond 25 years but the above range covers "normal" situations. The electrolytic caps may loose storage capacity before total failure. Replacing these caps will usually cost $100 - $400. The rest of the components in SS amps are likely good for at least 50 years. The caveat is that some transistors are no longer available so if you have catastrophic failure you might be in trouble.

Well, if Bryston guarantees the many thousands of amps they have out in the world for 20 years, then you can probably use that number as a good baseline.

Atma-Sphere has a 20-year design rule for the simple reason that 20 years is about as long as you can reasonably expect filter caps to hold up. After 20 years, even if they have not failed outright, it is a good idea to replace the filter caps anyway, regardless of the technology of the amplifier or preamp.

A friend of mine was a big Cello fan but one day the unit was making a thumping sound. I checked it out and a filter cap in the regulator had dried up. For guys like me the days when Cello was in business is not that long ago- so you can use that as a yardstick for what you are up against.

One further note- if the unit has sat in a basement or garage unused for more that a year the filter caps should be replaced regardless of the age. Caps don't take well to sitting around without a charge on them, much like a battery! So if the unit has been sitting a long time it should be regarded as suspect even if it is not that old.