Warm-up time for amps and preamps


How long does it take for your system to sound good from a cold start?
I try to keep my system on most of the time.  But occasionally I turn it off and it sounds like crap for a good half-hour to an hour.
i know there has been discussion here on the virtue of leaving tube preamps on all the time.
But my solid state amp (modified NuForce mono blocks) technician advises turning even them off occasionally.
128x128rvpiano
Great posts!  My Don Sachs preamp takes few minutes to sound its best and my McCormack DNA .05 Deluxe SS amp clearly takes a 30 minutes to sound optimally.  "Ear-lube" attributed to a beer or two might bias my impressions as "donjr"suggests above.  As a green-leaning guy, I can't bring myself to keeping my gear powered up 24/7.  
"allowing the processed signal from you cartridge (or other source) to complete transmission thru your speakers, where the signal is processed thru the tube grids opposed to the tubes in an idle state, speaker motors in a working state warming up and working the surround material, interconnects transferring signals, etc."

- say whut?
Once turned on my tube amp takes 60 seconds before sound can be heard. That is for amp protection.  Just enough time to pour the Jamison. Sounds great from the start and better every sip. 
I'm not a scotch drinker, but my tube system sounds better after a couple of beers. Seriously, I think both the amps and pre-amps are in their stride after a half hour's running from a cold start. Leaving the pre-amps on 24/7 is just a waste of electricity and more importantly, a waste of those priceless electrons. When I hit the feathers, everything's off.
Everyone is basically correct here. Solid State equipment usually takes about 30-60 minutes to get warm and stable. Electrolytic caps don't like heat but like being charged all the time. Tube filaments should always be on for a at least 30s before HV is applied. Using tube rectifiers automatically fixes this issue as they don't put out any HV until they themselves are warm. This BTW does not only apply to HiFi equipment but also to e.g. microwave ovens and radar transmitters. They need about 5 minutes to get warm since the magnetron is a big solid lump of metal. The ideal solution for tubes would be to have a low voltage pre-heat applied to the filaments all the time that keeps them warm but not glowing. 

So what should one do? Leave equipment on or switch them off? Well, It comes down to for how long time it will not be in use, the amount of energy it consumes when idle vs in stand-by or off and if you want to wait for it to warm up...