Reliabilty, Keeping Equipment Powered on or off?


I generally keep my system components powered on because the system does not have to "warm-up" when I sit down for a listen. I do know that reliability is usually calculated by POH (power on hours) however this calculation IMHO is a broad brush stroke. I do power down certain components that are not required to be left on to sound their best, such as a Luxman T-117 tuner and Wadia 171i Dock . However, my Krell IA, with the volume turned all the way down runs pretty hot, so hot you can't leave your hand on it. When turning the volume up on the Krell to reproduce the live event sound level, you can fry an egg on it, so I can only guess the Krell was designed to handle this kind of heat? However, back to the other components, such as DAC, SACDP, Headphone Amp, etc. Is keeping everything turned on asking for trouble or is leaving it on best to prevent thermal expansion and contraction which may be detrimental?
grm

Some of the replies have suggested there is no right answer to this question, I beg to differ. I am not by nature, a tree hugger, but we do have to consider finite limits on the worlds fossil fuels, if not, Global Warming.


I think we have to distinguish units with and without a standby facility, or those that automatically switch to standby when not in use. Units that stay powered on, particularly Power amps and even more so, Power Amps that run warm, usually Class A, are using an appreciable amount of juice. Just how much power does it need to heat up a heavy metal cabinet with components that don't include a heating element.

 Something I don't think that has been mentioned, is fire risk. The commonest cause of house fires in the UK, is electrical equipment left on standby, admittedly mainly TVs. I have never heard of a HiFi Rig causing a house fire, but it must have happened.


 All in all then, I think kit should be turned off when not in use for a number of hours. I do believe kit needs to warm up to reach optimal sound, but in my experience, this does not usually take more than half an hour.


My REL subs are always on, but the standby power is so low as to be insignificant. The rest of my gear warms up (tube amp) and sounds great. The "right answer" is to turn everything off since the benefits described by ANY manufacturer are minimal, but, as I noted earlier, people have lost the climate change battle as India and China ramp up thousands of coal plants, overpopulation driven by ignorance is likely to remain unchecked, and audiophiles deserve to have as much fun as possible. They just do.

The part that always seems to fail for me is the on/off switch.  My Classe amps suffered multiple switch failures.  The Cary integrated has needed a new switch as has my VAC preamp. 

Stuff breaking is just part of reality.

Uh…just had to leave town for 3 days due to unexpected family thing and uh…left everything on including my tube amp. Man...
Turned everything off last night after leaving everything on for an extended period of time (weeks). Well, when I powered on the Krell, there was a distinct "pop" sound, now the remote control does not work! Learned my lesson.