Lifespan of a quality solid state amplifier?

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Here is another concern. My company has been dealing with this for several years now. The caps in the computers that run our equipment are failing at a very high rate.

http://en.wikipedia.org/wiki/Capacitor_plague

I agree that MTBF is not applicable when talking about caps. It applies to complex equipment that needs to be repaired and put back into service. The time it takes a cap to fail is simply lifetime. Failing caps may lead to a lower MTBF for whatever they are installed in though.

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I might be halfway through my life and I feel radioactive sometimes so it's "win win".

English is an evolving language.

'Half life' works really well in this case since you have the statistical issues of a single cap and also that of several.

In the case of a single cap its half life is 20 years on average. IOW, you will find that it may well have dropped to half its capacity, with its ESR likely more than doubled. I have never seen caps over 40 years old that are safe to operate; but by that time they should be replaced, without question.

In the case of a bank of filter caps it will be found that in 20 years time half of them have reached the end of their useful service life, by leakage, by shorting, or simply so ineffective that the equipment using it no longer meets spec.

It seems that 'half life' works very well for this. However if sensibilities are offended (we're not in Alice's Wonderland, apparently) then MTBF is fine.

Herman, A few years ago I heard about a Chinese firm doing some corporate espionage. Apparently Panasonic had developed a more effective dielectric for their electrolytic caps. Fearing the discovery of their formula by competitors, they kept it in 2 halves in different locations. How I heard it was that the Chinese company had managed to get one of those halves and used it in their caps, which got used in a lot of computer boards that began failing about 6-8 years ago on this account. Is this anything like what your firm was experiencing?

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Ralph,

Again, I'm dumbfounded you continue to defend what is clearly wrong.

I've been dealing with electronics for over 30 years, taught it for 10, and have looked at this topic quite a bit since it often comes up on this and other forums. I've never seen it mentioned that 1/2 fail in 20 years or any other statistic that puts a lifetime like that on them. Any data always factors in temperature and voltage. I really respect most of what you say here but you clearly have no real data to back up any of these 20 year claims.

Yes, English evolves but that doesn't mean it is acceptable to use it in any way you wish. Half life has a very clear, concise, scientific definition and your use of it is well outside that definition. Ir would be nice if someone on these forums would just once admit they are wrong.

MTBF to describe cap failure is also incorrect as stated above. It refers to complex, repairable devices, not components. How can you possibly have a "mean time BETWEEN failures" for a device that is thrown away when it fails? There is never a second failure so there can never be a between. From this article

MTBF is properly used only for components that can be repaired and returned to service.

Yes, I suspect the caps we are seeing fail are part of what you talked about. I posted a link to it in my response above.

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Good question. I don't think there is really much required in the way of care and feeding. I am on more than 20 years on my PS Audio 250 Deltas, and they still sound fantastic.

That said, there are problems that crop up with amplifiers, tubed as well as solid-state, lord knows why.

Not sure that there is really a defined lifespan, but for the prices we pay for some of this stuff, it should be forEVER, right?