Should an audio system be left on at all times?

I have always understood that leaving a solid state amp on all the time lengthens it's life, I leave mine on.

Pdn: I was talking about SS. As for time - it might vary and I don't know of any rule. I'm pretty sure the same applies to tube gear but have no experience there.

Stanwal: It might be better to leave computers on all the time (because of hard disc) but computers are often replaced before they go bad. The only component that ages in SS amp is electrolytic cap. As far as I know its life is only temperature dependent (except when left unpowered for years).

If your amp is not hot or cold to touch (body temperature) its life is already reduced by half compare to room temperature (10 deg. Celsius difference) - important only if you plan to keep gear for more than 10-15 years.

Kijanki,

So the wear of higher operating temperature exceeds the wear of powering your system up and down everytime you want to listen?

Knownothing - I think so. Capacitor companies like Nichicon mention only temperature as limiting factor (and not the rush current).

My experience and reading make me believe that the powering up and down produce more wear. I have transistor amps 25 years old I leave on all the time. I have never heard of heat being a factor in amp deterioration . I have often heard of an amp going bad from not being used. I think this is another case where theory and the real world differ. The ONLY argument I have ever heard against leaving them on is the cost of the power. In every case where I have seen this discussed the author has stated that leaving them on prolongs their life.