Capacitor life is function of ambient temperature. Each 10 deg C temp increase cuts life of capacitor by half. It is shown in many studies and published by pretty much all capacitor manufacturers. You can also find here: http://www.niccomp.com/help/presentations/AlumE-CapExtendedOperation0809-revA.pdf
on page 8 that this characteristic is same for different capacitor families. Assuming that good grade capacitor is designed to last about 50-60 years at room temperature it is most likely only 25-30 years since amps powered are often 10 degC warmer.
As for SS electronics being damaged from turning on and off - the only thing that gets damaged is power switch. Other than that semiconductors last pretty much forever - from SCRs doing millions of cycles in welding machines to Mosfet transistors switching 500,000 times a second under full load in output stage of my class D amplifier. Semiconductors have lifetime (everything has) but it is greater than your lifetime.
Other than power bill consideration you might find different claims on sound change. Many claim best sound after 24hours powered while others cannot hear any difference after 30 minutes. You have to decide for yourself. Take into consideration that you might need some time for your speakers to obtain full performance. Many tweeters, for instance, use ferrofluid that has some change of viscosity with temperature. My 6.5" midrange speakers use ferrofluid as suspension.
I keep my gear on all the time because of low power usage (class D amp) and very good overvoltage protection. It takes about 30 min for the speakers to warm up.
on page 8 that this characteristic is same for different capacitor families. Assuming that good grade capacitor is designed to last about 50-60 years at room temperature it is most likely only 25-30 years since amps powered are often 10 degC warmer.
As for SS electronics being damaged from turning on and off - the only thing that gets damaged is power switch. Other than that semiconductors last pretty much forever - from SCRs doing millions of cycles in welding machines to Mosfet transistors switching 500,000 times a second under full load in output stage of my class D amplifier. Semiconductors have lifetime (everything has) but it is greater than your lifetime.
Other than power bill consideration you might find different claims on sound change. Many claim best sound after 24hours powered while others cannot hear any difference after 30 minutes. You have to decide for yourself. Take into consideration that you might need some time for your speakers to obtain full performance. Many tweeters, for instance, use ferrofluid that has some change of viscosity with temperature. My 6.5" midrange speakers use ferrofluid as suspension.
I keep my gear on all the time because of low power usage (class D amp) and very good overvoltage protection. It takes about 30 min for the speakers to warm up.