Should I leave my equipment on ?

All solid state equipment, no tubes...Adcom 535 amp, Parasound pre amp, Cambridge Audio cd....should I leave everything on all the time, or turn off if I wont be using it for awhile ?

Does leaving everything on amount to a lot of energy wasted ?

Comments to this bid time neophyte are appreciated.
In my opinion equpment varies--as to the value of leaving it on. I had a Moscode 600. (tubed/mosfit hibird) I owned it for years. I used it for the rear ch in HT application after purchacing a new amp. Then I had to take the newer amp in for service. I stuck the 600 back up for 2ch duty.Quite as come down as I remember,for that night's session. I had always turned it off. This time I left it on. After about 30 hrs of being on I was astonished at the improvement.Didn't sound like the same amp. Long story--- My suggestion: listen both ways. Leave it on for 2 days---listen---- then turn it off.Then say 12/18 hrs later listen again--after only a 1hr. warm-up. Then you will know how YOUR amp performs. As far as everything else without tubes---leave it on full time.
Avguygeorge put it well. Experiment and let your ears tell you the answer to your question.

From my own personal experience, solid state sounds better if left on all the time. I unplug my Rega Planet (which is typically always on) when I'm out of town for more than a week or when there's a thunderstorm. It always takes it at least 48 hours to start sounding good again. A while back, I ran a full Adcom rig - 555 pre, 545 amp, 575 cdp. It too sounded better when always on.

As far as power consumption is concerned, your equipment doesn't draw much wattage at idle. Your whole rig, when at idle, probably consumes less wattage than a table lamp.
I'll only add that some gear, such as high bias AB or Class A amps will pull considerable power all the time, even at idle. This means that they have to be able to dissipate heat. Since they do tend to run hot, these devices tend to show the most marked difference between "cold" and "fully warmed up". This probably has to do with the fact that they have the greatest temperature swing from not being powered up to normal operating temp. Switching or digital amps tend to show little difference in my experience since their temperature variations are not very much at all.

As far as digital goes, how it sounds cold and "hot" will vary depending on the stability of the circuitry used. Most "decent" digital gear will obtain excellent stability within 4 hours of being powered up. Some designs, being slightly more stable than those mentioned above, will come up to operating temperature faster than that.

As a side note, my $18K Military Spec signal generator is not worth "mud" until it has been on for about 2 hours. According to the manufacturer, it should achieve total stability within 15 - 20 minutes of turn on. On the other hand, the sig gen that my business partner uses ( same model but lacking higher grade Mil Spec parts and cost about $3K less ) seems to be just fine after about 15 - 20 minutes. Both units easily meet spec and were recently calibrated, but it just goes to show that there is obviously a difference due to parts tolerance.

The bottom line is that you have to try them and see what works best for you. Personally, if i was going to conduct such a test, i would leave the system powered up for at least 48 hours and preferably 72 hours and then give it a listen. If you notice a difference that seems to be worthwhile, leave it powered up. If it does make a difference but you are "frugal", try experimenting with what sounds best left on and what doesn't seem to make much of a difference. You can then power up / shut down as needed. Sean
I have found in my system that when I leave all equipment on it sounds better. If for some reason I have to turn my system off to install a new peice or what ever I find my amps take the longest out of all my equipment to warm up, about 24 hours to get them to there best but after 2 hours I find them about 75% sounding good. With the digital I find only about one hour is needed. So I leave my equipment on 24/7!
I have done this for the past ten years, also you'll find most Co. telling you to leave on 24/7, for tubes it's another story, as I think you want to power up one hour befor listening, but after 4-5 hours of being powered up tube stuff seems to sound good. have a Sonic Frontiers sdf-2 D/A and it has a stand-by swith so I can fire up the tube output before I give a listen, the SDF-2 is alway on internaly except for the tube section. Sonic Frontiers says to turn on 30 minutes before to warm up and most tube Co. will say the same. Hope this helps and good Listening!
Post removed 
Elizabeth, you're close! Actually, it's the coupling or storage capacitors in the amp/preamp, that take time to charge, stabilize, and reach optimum performance. The cross-over networks in most speakers are passive, and are good to go, immediately. Of course, new speakers will take time to "burn in" the cross-overs and drivers to reach optimum sound. And if you don't play your speakers for several days, it mat take a few hours for them, as well as your cables and interconnects, to reach peak performance again.
Thanks to all for such comprehensive answers. FYI what prompeted this question was, among other things, comments I've read from some audiophiles who stated their equipment has NEVER been turned off.

Here is a similar query- I'm currently evaluating different pieces of equipment and interconnects, etc. I have to turn some things off to switch things around. If the equipment is turned off for but a few minutes after it's been on for , say several days, is that the equivalent of a full blown cool down ??

Thanks again to anyone with advice for me.
Even if the equipment is turned off for a few minutes it usually means that it will require another 24 hours to stabilise on turning back on.
pre-amps should stay on all the time they draw very little power.when it comes to amps though if there is no stand-by the bill at the end of the month can be excessive.leaving my three bryston amps on all day as well as two mark levinson amps cost about 200 can dollars a month.i use the bryston's for home theatre and the levinson's for audio.the bryston's being turned off did not make any difference to the movies.the levinson's have a standby switch which just keeps the amps warm,it sounds great and the electric bill is a lot cheaper.hard to believe but i monitered this over an eight month period.good luck
Side note... If you have the Cambridge CD players with the IEC power socket, then upgrade your power cord if you've not already done so. Makes a big difference. For $80 I'd recommend the Blue Circle BC61.