Actually, leaving it on will allow the components last longer. This is primarily due to less heat cycles. Heat cycles is what kills solder joints. In the Navy we left the electronics on all of the time. So, on the sub i was on.. Most of the electronics were close to 20 years old....
This is why I'm back and forth on this. I've historically left my subs on, but when I was also leaving my main amp on, a part decided to go wonky (can't remember what they said it was), but when I told them I was leaving it on 24/7, they said that was a bad idea, and I should be turning it off when not in use. I remember this conversation coming up before, so I explained why I'd been leaving it on, but they still suggested turning it off. Since I use my system every day, that is a lot of cycling of power. I've been turning it off every night since then, but I'm still not sure what's worse for longevity.
