Lifespan of a quality solid state amplifier?

A couple of things. 1) most decent amplifiers have soft/slow start circuitry which prevents the on/off cycling problems that people mention here. Therefore for a decent high end amp, the cycling on/off damage they are talking about really isn't an issue anymore. 2). Electrolytic capacitors would be a problem and must be checked. They are like any other component in cars, etc. they give you advanced warning that they may probably fail. yes, yes, there are instances where something just simply goes out, but in most parts you can see leakage before they fail. So, take a good look inside or have a qualified technician inspect the unit to see if any problems may exist. If nothing is apparant, then leave it alone until some problem or possibility of problem presents itself. 3) apart from capacitors, the thermal damage due to the loss of heat sink compound that the transistors are using when connecting to heat sinks may be the major issue. Transistors fail for a number of reasons. a) people that short the outputs when playing with speaker cables are the number one reason. b) when the heat sink compound dries out, it presents a problem for loss of thermal conductivitity and also allows for the possibility of the transistor to come in contact with the heat sink, because not only is the heat sink compound gone, but the thermal insulator between the transistor and the heat sink may be damaged. Therefore, what I typically do with older amplifiers is to check the capacitors for leakage and replace if necessary (only if necessary) these suckers are expensive, and replace all pre-driver and output driver power transistors with the newest, latest and greatest more linear transistors and readjust the bias, which makes the amp much better sounding. This also allows me to replace the thermal insulators and the heat sink compound, thereby eliminating any possibility of the amp having issues. my "modified" amps are much better sounding then the original and also are much longer lasting because I have inspected and replaced capacitors where necessary and also I have replaced all pre-driver and output power transistors and their associated thermal insulators and heat sink thermal compound.

One last thing. I typically will add a slow start/turn on relay circuit to any amp that does not have it originally and I sometimes will modify the power supply to separate power supplies with regulators.

After all that, I guess what I am saying is for really old amps, definitely change the heat sink compound and thermal insulators at a minimum and if you can change all output transistors also and check and replace if necessary the electrolytic capacitors.

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Herman; Thanks for the response. Typically I don't measure a loss of capacitance per se. What I check for physically, visually is actual leakage that is noticible on the capacitors. It is obvious and very easy to see. Others have stated that what they do is simply replace all electrolytic caps. This is also another way to go. I can tell you most electrolytic caps aren't that expensive, but power supply filter caps can really get up there in cost if the rail voltages are high. This is one reason why amplifiers are so expensive. The others are 1) transformers (very high cost), transistors and tube, can get up there in cost if they are speciality devices in low production, 3) machining enclosures, that are well designed and built to eliminate vibrations (i.e. very heavy), rediculously expensive heat sinks, etc. But the only times I typically measure capacitance is when I'm reverse engineering something. or if I simply can't read the lables on the devices because they are so old. But the originally poster's question regarding lifespan of ss amps assumes that there is no routine maintenance of the equipment. Like cars, amps and electronic equipment (that you want to keep operating for decades do need maintenance.) a qualified service tech can do it for you. Replace caps with equal or better quality caps, replace transistors, resistors, tubes, diodes, heat sink compound and thermal insulators, etc. and you basically have a brand new and maybe better amp. But for regular people that don't have the technical background to do this, I recommend that they just enjoy. However, it depends on the equipment. If, for example one gets their hands on the older top-of-the line Audio Research, Threshold, Mark Levinson, Atmasphere, etc. equipment, I would definitely try to service it and get it working correctly and keep it. If going to a "fire sale" and I find two Mark Levinson 20.6 amps, I would do whatever it takes to get those working correctly and keep them. Some older equipment is as good or better then most newer amps today. believe me.

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Thanks Herman; Actually, it is only too late if it fails, which I have never seen happen if the units are periodically inspected and serviced. Again, like a fine automobile, if units are routinely inspected and serviced this type of problem will be detected early enough to warrant replacement of parts before failure. Another warning other than visual leakage is lose of sound quality of other electrical issues. But, as I mentioned earlier, if the unit is routinely inspected and service, even these will be detected early enough and parts replaced before failure.

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Thanks Atmasphere; you are entirely correct and I also replace caps if I notice the bulging plug. I forgot to mention it. Again, for those interested, this is part of routine inspection and service. For expensive high-end electronics, this is something that I definitely recommend.

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Routine maintenance, inspection and repair is required for any high-end piece of equipment. The same logic you apply to upper quality cars, home, etc. should apply to delicate, high end equipment. If you find a quality older high-end amplifier for example, send it to a qualified service technician for inspection and maintenance. If the amp is older, then they should automatically tell you that the caps should be replaced on general principle. However, also, checking the wiring, connectors, boards for burned traces and wear is automatic. I already posted comments regarding transistor, insulator and thermal heat sink compound replacement. This is automatic for a qualified technician. For someone that isn't properly trained, they wouldn't know what to look for or how to fix it. But, again, it depends on the equipment and whether there is inherent value in it. My earlier example was if at a "fire sale" you find a pair of Mark Levinson 20.6 amps. Absolutely, I would do whatever is necessary to bring them back to top shape and keep them. Capacitors, transistors, etc. But the other example whereby you have a 30 year old low to mid fi panasonic amp. It probably isn't worth it to replace anything. For high voltage power supply rail capacitors for example, they are really expensive. Large TO3 Motorola output power transistors are about $10 each. If your amp has thirty of those, well things start to really add up, incluing labor charges. I find it fun to repair and upgrade older 70's receivers because they are really nice, especially the huge ones with wood grain panels. So repairing them is okay for me. Caps, transistors, the whole thing. But the original poster said "quality solid state amp" Therefore a ML 23.5, ML23, Threshold, Bedini, etc. Yeah! I would inspect and maintain them. As for sound quality of capacitors, well if they are in the signal path, definitely, they affect the sound. But, everthing loses value over time. Older resistors change value. Don't believe me? check it out. Caps, transistors betas change over time and with heat and long term use. it isn't just the caps that would do this. So the argument about caps affecting sound is really not the point. The point is, on an older quality amp, what is the lifespan? The answer is, it depends on what you do to it. And that is proper routine inspection and maintenance, and that totally depends on the knowledge and experience of the qualified technician performing the work. Also, this also applies to older quality tube amplifiers. Proper inspection and maintenance.

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