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.
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I've got a Simaudio 700i amplifier and if I unplug it from the outlet it takes several days before it sounds like magic again.  Using the standby switch on the front panel only mutes the inputs and turns off the front panel display.  The amp stays just about as warm in standby as it does when it's turned on without music playing.  I've heard it draws around 70 watts or so in standby and 90 idling.  They must have a reason for designing it in this manner.  I never unplug it or use the rear panel AC switch unless I'm going away for longer than a week or so.
reality is your brain ......'psycho - acoustical' part takes longer than most of ones gear.  First half hour for your components, the second half our for the brain to 'accept it' !

What are all you guys smoking? With SS equipment, it only takes a fractions of a second to reach stability, with tubes it might take a few seconds only! How can you prove that what you hear 45 minutes later from the same source and media sounds any different?
" How can you prove that what you hear 45 minutes later from the same source and media sounds any different?"

Why should anyone here have to prove something? If you don't feel its necessary to warm up your system, great. If others want to, that's they're business. Besides, its hard to find an owners manual that doesn't discuss warm up. What proof do you have that they're all wrong?
for the same reason that anyone here should have to exercise correct word choice - a question was asked and people are giving answers


as to how to test - you would want two copies of the same component - warm one up (w/o listening) for an hour or two and then A/B/X them