Transistor gear, leave on all the time. Tube gear, I usually leave on, unless I know I won't be using it for at least 24 hours. In addition, many tube amps have a plate voltage switch which can be turned off while leaving the filaments powered up. This can add many hours to the life of the power tubes (I usually shut down plate voltage if the amp won't be used for several hours). DON'T TAKE A CHANCE WITH A RANDOM LIGHTENING STRIKE!!! If there is the possibility of electrical storms, shut down an UNPLUG EVERYTHING! Contrary to popular belief, a surge protector will not help if you receive a direct lightening strike on a power line going into your home.
