A little common sense goes a long way...if you are leaving the house, or there is a big electrical pull on your system from Air Conditioning or tools that you will be using, or a washer and dryer, sump pump, etc., or there is a thunder storm brewing, by all means turn off the amp first, wait at least 5 minutes, and then turn off the preamp. Under normal circumstances, turning the amp on in the morning and off when you go to sleep doesn't hurt the equipment and will add quality to your listening session.
How should you treat your tubes?
I recently swithed from SS to all-tube amp and preamp. I usually listen to my stereo in long stretches throughout the day and evening but there are also intervals when I am not listening. My question: Do I turn off the amp and preamp during those intervals which may last as long as an hour or two hours? Or do I leave my system on during the day and evening and turn it off at night? Thanks for any suggestions. JNorth1178