One of the things about living in the Southeast is one must become accustomed is summer thunderstorms. This is not to say other parts of the country are lacking in such weather, it's that the Southeast can easily have several each week. Thunder, lighting, hail, driving wind and torrential rain is not uncommon. And for whatever reason, there is the occasional loss of power. When that happens, it always scares me because I rarely power my system off - unless I will be gone for an extended period. I do so because I try to avoid one the more curious aspects of high performance audio, equipment warm up.
For most things in our life we turn on a switch and the thing powers on. No waiting, no fuss, just flip the switch and presto, instant use. So it was the other day, when we were having one of our more common 4:00 PM summer storms that usually lasts an hour at most, my power went out. Poof - no lights, no A/C and no stereo system. This always besets a feeling of apprehension because I worry when the electricity is restored, my system powers up, some sort of overload happens and something subsequently burns up. Why take the chance? Simple, I leave my system powered on so I can avoid the time necessary for it to warm up and sound its best. For my system, that time frame is about three hours. Certainly more time than I have or even want to spend waiting on my rig to sound its best.
Warm up is one of those believe it or not things and like so much in audio there is no real clear cut answer. If you have tube equipment, it's probably not wise to leave it running 24/7. Unless, of course, you like additional heat in the room, increased energy costs and best of all, frequent replacement of those expensive vacuum tubes, or "valves" for those in Europe. If you have solid state equipment it's a little different. Class A amps, particularly those with no bias control, create considerable heat. If your class A amp does have a bias switch that can throttle down the power at idle, then it is not so much of a heat producing, power consuming component. Class A/B, one of the more popular solid state amp designs, do tend to run warm, but not hot, so leaving them on all the time may not be as problematic.
My A/B amp is constantly powered on. Much debate swirls about Class D, or switching amps, and the presumed wisdom of having the power on when no music is playing. Other components such as preamps, DAC's and typical source components generally consume little energy anyway so the threat to them is likely not as great as an amp - depending, of course, on the actual component, design and manufacturer.
Another consideration in all of this are things like transformers and capacitors. It is undeniable these parts of any component can and do wear out at some point, although that time can be quite varied. Some receivers still work fine forty or more years after their manufacture.
Still, because a capacitor, for instance, is a device that stores a charge when power is applied and eventually drains the charge when power is removed, the life of the capacitor may be shortened the more charging and discharging that occurs. Leaving a cap charged all the time therefore seems to make sense. And then there is the question of the capacitor type and how it might react to constant power and if it will leak. And on and on and on. This is a discussion with many different variables.
Another factor worth mentioning are utility costs. How much does it cost your monthly power bill to run all these components night and day? 10% more? 20%? More than that? At my previous residence I tried an experiment.
I left everything powered on for one month and off for one month. I only noticed a utility cost difference of about $20.00, and that could have been because of other factors such as how much I was running the HCVAC, dryer, stove, etc., etc. In my current home I have yet to check because I have yet to really care how much it costs my power bill. I want the system powered on all the time and so it shall be, utility costs notwithstanding.
Recently, during one of our all too common storms, my power went out for about a minute. As previously stated, this always concerns me. When the electricity was restored, I went to my audio room. I powered everything back on, in the proper order, and decided to play some music just to be sure everything worked. Immediately I noticed how different the sonics sounded. Did I say different? I meant worse! I could not believe how bad things sounded compared to what I was accustomed to hearing.
Deciding to wait, I kept listening and after about an hour, I noticed that all of the sudden things sounded much better. I went downstairs and came back to the audio room three hours later and whaddya know, it sounded normal once again. In my mind that confirms the validity of warm up. However, I do realize there are those that do not believe in the concept for any number of reasons. I will only go so far to say that for my system, warm up is very real and undeniable. I believe in the practice of keeping my system powered on all the time. I don't have the time, or desire, to wait three or four hours for my system to sound its best when I decide I want to play a song.
Like so many audio subjects this one can be, and has been in the past rather divisive and without agreement. And that's fine. Each to their own. All audiophiles should have their own methodology and do what works best for them with their system. Regardless, warm up is a very real aspect of an audio system. Whether it is a believable aspect is, as always, up to the individual audiophile.