Maybe if it's solid state, I wouldn't if it is tubed equipment, why waste the life of the tubes? I never understood what the advantage was to leaving it on. I have tubed equipment that I turn on about an hour before I want to listen to music, that seems to be enough warm up time. Even it I wanted to keep it on, my wife would never feel comfortable leaving the house all day with equipment turned on, afraid of a fire or something to that effect.
