I often leave my Lepai on for 12 hours or more at a time. It never even gets warm. I do get a little pop when turning it on or off. I have an active subwoofer connected to it that has an "auto standby" feature. I leave the sub set on "auto," so the sub is powered 24 hours a day. The sub always has power when I turn the Lepai on or off. I've never run into any problem with turning the Lepai on and off or leaving it on. However, I do get a little pop, so it's always set at low volume when I turn it on or off. I don't think I would try turning it on or off with the volume cranked, but I've never had any problems at low volume.