I agree with Gs5556 on all points. I might add that I think that on/off cycles may affect tube gear, but not SS. It's no coincidence that light bulbs typically burn out just when they're turned on, not when they've already been on for a while. I would expect tube filaments to behave similarly for the most part. It might be good to check with the manufacturer of your component. My favourite manufacturer states that leaving its gear on all the time causes no harm other than using electricity. However, they also advise that if you're not around for any length of time, you should not just turn it off, but also unplug the mains. A lightning bolt that can arc a mile through the air isn't going to have any trouble with the gap at an on/off switch. I've personally had a surge suppresor die in the line of duty protecting my gear from a power surge during an electrical storm. Now when I hear thunder, everything gets unplugged.
