Good posts ... interesting subject. I leave my equipment (amp, CD, DAC) on all of the time. The DAC has no power switch, the amp's switch is hidden around the back (hint hint) and the CD player has such low idle power consumption I don't worry. I think it sounds better, and I think that the lack of thermal cycling will help extend its life. I have also heard that electrolytic caps like to be left powered.
During an electrical storm I not only switch off I also unplug the equipment from the outlets, since a little on-off switch may not protect against the sort of surge a lightning strike can deliver. If any storms are in the forecast then I leave the equipment this way and revert to the portable CD player. If you have an FM tuner and an outdoor antenna I would also unplug the antenna during a storm ... even if it's not struck it can still reach high voltages and damage the tuner due to the electrical potential differences in the atmosphere. Paranoid ? Perhaps, but I have lost a TV to lightning, and I'm a lot more attached to my hifi than my TV.
During an electrical storm I not only switch off I also unplug the equipment from the outlets, since a little on-off switch may not protect against the sort of surge a lightning strike can deliver. If any storms are in the forecast then I leave the equipment this way and revert to the portable CD player. If you have an FM tuner and an outdoor antenna I would also unplug the antenna during a storm ... even if it's not struck it can still reach high voltages and damage the tuner due to the electrical potential differences in the atmosphere. Paranoid ? Perhaps, but I have lost a TV to lightning, and I'm a lot more attached to my hifi than my TV.