Do you leave your components on 24/7?

What Mcintech said about the wine was seriously funny.

I am an EE and have been one for over 30 years with analog/digital and amplifer/filter design and test background. I am also a state registered Professional Engineer. Go figure. However, I will state again, Leave your equipment off until you are ready to listen. Turn it on with sufficient time to properly warm up and begin listening. When a signal begins to flow through the system the warm up time is faster. Except for pure class A equipment, which, depending on the bias points (and class A means different things to different Engineers), may be faster than others. As others have mentioned, pc boards get brittle over time with heat. Other components were not designed, nor tested (trust me) to be operated "on" 24/7. Look at any serious audio magazine. Do they review or rate your older (more than 2 years old) equipment? most times not. So, manufacturers have to have their products in the magazines in order to make money (in their opinion). So they have come up with the latest and greatest and newest equipment. Which in many cases is really not better than the older stuff they produced. But, their names will not get mentioned in mags, nor reviewed unless the equipment is "new". So, they really want you to either 1) buy their newer stuff, or 2) bring it in for repair. Would you think that audio equipment is treated any diffently than cars? Dealers make their money on maintenance, not sales. Most high end equipment have soft start circuitry that seriously reduces the chance of turn on failure. My equipment stays off until I come home from work and then I turn it on, do a few things around the home, and then I sit for my enjoyment.

That said, enjoy

One can have enough degrees to be a thermometer(I only got two at Case Institute), and they will do ABSOLUTELY NOTHING for the individual's aural acuity, or their system's resolution(just two of many possible variables). My BAT VK-D5 CDP has a, "Standby" feature, that keeps the circuits/tubes warmed up at half voltage(designed that way, by BAT's resident Rocket Scientist, OBVIOUSLY for a reason). My SS bottom end amp, TacT pre, and Phono pre, stay powered up 24/7. My tubed mains amps are powering up at least an hour before listening. I'm certain Julian Hirsch(of Everything-sounds-the-same fame) would be proud of those that can hear no differences in well warmed up gear(or perhaps: have never heard well warmed up gear). BUT- As long as YOU are happy with your system's presentation- HAPPY LISTENING!

Indeed, an amp manufacturer will rightly claim the amp sounds better left on, and until it fails I'm sure it does. A car runs better when warmed up...leave that car on! If my gear is on and nobody is listening, does it sound good? Hmm...

Wolf ... Most taxi's are left running . Ever wonder why taxi's get into the million mile or more mark ?
Our cat hates being left along , if she see's we are getting ready to leave she will run to the listening room and curl up in the sweet spot and hardly notices were gone .
We don't want to anger the animal activist's there likely tougher than the environmentalists . There's no keeping everyone happy . Ya-Ya I know thats a pretty lame excuse .

I think people give way to much credence to what the manufacturers say, specifically to reliability and turning the amp off or leaving it on. I'd bet most have no hard data to prove either way, it costs a lot of money to do those types of studies and it takes a long time. There is no reason for a manufacturer to incur those costs.
If they told everyone to turn it off when not in use, there would be some portion of the user population that would turn off / on multiple times each day. This is what they're probably trying to avoid by telling everyone to leave on 24 x 7. That, and it sounds sexier if you are told that the amp you just bought "Needs to be left on to sound its best."