Should an audio system be left on at all times?

Stanwall - Check this link: http://www.dfrsolutions.com/pdfs/Uprating_of_Electrolytic_Capacitors.pdf

They mention temperature as main factor (and 10 deg C rule). ESR while getting lower at high temperatures (might explain reason for warmup) eventually gets higher from electrolyte evaporation.

Good quality amp equipped with 105 deg C caps might last for very long time while luke warm. I would like to preserve my amp at current state as long as I can.

Well, no matter what, having your amp off most of the time will save electricity. You can use the money you save on your power bill to go stimulate the economy...

Maybe if it's solid state, I wouldn't if it is tubed equipment, why waste the life of the tubes? I never understood what the advantage was to leaving it on. I have tubed equipment that I turn on about an hour before I want to listen to music, that seems to be enough warm up time. Even it I wanted to keep it on, my wife would never feel comfortable leaving the house all day with equipment turned on, afraid of a fire or something to that effect.

Cyclonicman - I don't understand advantage of leaving equipment on all the time either. Other elements of the system - like speakers also need time to warm up (playing time).

Even if Stanwal is right about miniscule effect of time on capacitors (electrolyte evaporation) in low temperatures there is no reason to keep it on - rush current doesn't do anything to capacitors.

I turn my system (class D) on every evening ant turn it off at night. On days of bad weather forecast I unplug it from the wall.

Concerning solid state equipment, there have been endless discussions of this question over the years, concerning audio equipment, computer equipment, and all kinds of other electronic things, with no definitive answers, even among electrical design engineers (I am one, and I've discussed this question with others).

My own feeling is that the answer will be dependent on the design of the particular item, both the circuit design and the characteristics and quality of the particular parts that are chosen. Doing an analysis to definitively answer the question even for one particular design would be a formidable task, and could only be done if complete documentation on the design were available.

My bottom line suggestion for solid state gear is simply a common sense one -- if you use it frequently (e.g., two sessions or perhaps even one session per day) leave it on all the time; if you don't use it frequently turn it off.

Regards,
-- Al