Back when I repaired high-end audio for a living, a single lightning storm would easily pay my mortgage and car payments for a month . . . here are a few not-so-obvious observations from those years:
- Lightning damage doesn't always show up immediatlely after a storm . . . its common for semiconductor junctions to become damaged, and then outright fail after a little bit more use. CMOS components seem to exhibit this behavior the most.
- A unit's suceptibility to lightning damage is heavily influenced by lots of extremely subtle aspects of its design, especially its internal routing and size of ground traces and connections. Well-designed stuff simply breaks less, including from lightning.
- It's actually possible for equipment to be damaged by lightning even without being plugged into power, or having any connections made to it whatsoever. I personally had the electronics in an unplugged MIG-welder destroyed in this fashion - a cloud-to-cloud strike directly above my house induced a current in its large transformer core purely from the EMP field. So there are of course many situations where even a theoretically perfect surge suppressor will do absolutely no good.
In my opinion, the two best defences against lightning damage are:
- Making sure the household wiring is in good shape, and everything is up to modern standards and codes. Not necessarily in an audiophile-overkill sense, but if you have an older home with questionable workmanship in wiring from many revisions, or your system includes multiple wall outlets, multiple circuits, extension cords, and/or cheater plugs . . . or your home's electrical panel is stuffed full of doubled-up breakers and has poor grounding . . . chances are that you're more suceptible than average.
- Get a good homeowner's or renter's insurance policy, with generous replacement-value lightning-damage coverage on your electronics. Because in the end, when mankind goes up against Nature . . . we're bound to lose eventually.