Question about power surge protection


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One of my customers at my job just told me that just about all of his appliances were destroyed a couple weeks ago from a major power surge. Items such as his TVs and refrigerators were all destroyed and there was not even a storm. He lives a few miles away from me in the next town. We never heard of this problem and it is rare for our area. His wife is devastated at this huge loss since they are having problems with their insurance company. He even plugged them into power surge protection strips too.

This made me alarmed because I use the generic power strips that offer little protection and now I want to buy the high end power surge protectors like the Brickwall surge protector or the Panamax 5300 power box. My question is, do I have to leave them on at all times for maximum power protection or can I turn the power box off when not using my stereo system and still be protected?
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spareribs
I use Furman Elite 20PFi conditioner and leave system on all the time. It has positive effect on the sound and very good protection. It uses multistage non-sacrificial protection with circuit breaker. In addition it has separate filters for different output banks including high current bank where my power amp (class D) is plugged.

Lightning is something else, since there is no wire in the world that can conduct 1 foot wide plasma to ground. My relative's house was strucked twice (direct hit). All electrical equipment was damaged and insurance paid for it but when it came to renew they canceled because he was statistically too much of a risk. Statistics as we all know prove that motorcycle accidents are caused by tattoos but that's life. I protected my gear as much as as could. (I could install whole house surge arrestor in addition. It is probably not very expensive and is installed at the box).
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I picked up a Brickwall PW8R15AUD about a year ago after I'd lost a couple of tubes in my Mac on two separate occasions when the power went out and then came back on (the Mac was not switched on either time as I'm not in the habit of leaving it on).

Since then we've had several power outages and the tubes have come through intact each time. Just fwiw, I have not detected any falloff in the audio signal. Since then I've upgraded to better tubes making the Brickwall a break-even component, essentially.