Lifespan of a quality solid state amplifier?

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Minor, sounds like you are a very thorough tech.

Question: you say you check the caps for leakage and replace only as needed. What about a loss of capacitance and/or increased ESR? The amp may function with these problems but well below it's potential.

Also curious what method you use to measure the leakage.

Thanks

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Hi Herman, I too have taught in technical schools and my stint in the service industry goes back to 1974. That's how I financed my way through the Minnesota Institute of Technology. The use of 'half life' is my own and simply comes out of experience - as a service tech I have repaired thousands of amps, preamps, receivers, tuners, tape machines, etc. I'm sorry that the use of the term bothers you but it works so well and is so easy to explain that I will continue to use it. I'll try not to use it around you :)

Does this conversation really need to diverge toward the negative? You’d think this was Audio Asylum or something. I frequent these boards because they’re usually (significantly) more civil. It doesn’t seem like we’re furthering much useful conversation on the original poster’s topic, just arguing about semantic minutia.

Regarding MBTF (or MTTF) of systems, caps, half life, etc, I want to clear something up. For the exponential failure rate distribution, which most electronics follow during the majority of their lifetime, MTBF is when 63.2% of the population has failed, not 50%. When the product / part begins to wear out (failures begin to occur at an increasing rate), the normal distribution is typically used, and MTBF is indeed when 50% of the population has failed.

And getting back to the original question, I agree that good SS amplifiers can last 20+ years. Electrolytics are frequently the limiting factor, followed by the semiconductors (transistors, diodes). Much of this depends on how much margin the designers used (how much the parts are derated for relevant electrical and thermal parameters). Personally, I wouldn’t worry about any maintenance unless recommended by the manufacturer. Bringing up an amplifier slowly with a Variac after it has been out of service for 6+ months isn’t a bad idea.

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No problem Ralph. I think it is a disservice to those who are trying to learn something here but If you are comfortable muddying the water with incorrect information then that is your choice. As one of the senior "experts" around here who comes from a technical background I would think you would strive for accuracy but your choice. I think from now on I'm going to refer to tubes as transistors since they transfer a signal and both words have trans in them. It's not correct but it's just as logical as your use of half life :>)

Like I said, it amazes me that nobody around here will ever admit they are wrong about something. When called on something they either don't respond, change their story, or do as you do and rationalize their incorrect responses. Actually, I find it a bit amusing.

In any case I'm done with it. Carry on.

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Herman I repair 5v 200 amp switching power supplies and find that 70-80% of the fails are in the large filter caps used in the supply section;when I replace these caps I change all electrolytic caps in the supply as well as the fan.The supplies I see range from the 1990's and run 24/7 being used in large semiconductor test equipment;they are normally mallory 15000mfd at 7.5v and 4000mfd at 200v caps.
Did you company resolve their computer failures?