All that I can say is that my house has been struck twice by lightening. One time my system was not on but my computer was and had a surge protector. The computer was fried. The second time in another house, my system was on and lightening struck my water heater which was only six feet away. The system was all plugged into the Sound Application ac filter. Neither it nor the stereo system was damaged at all, although the water heater had a hole blown into the gas line, the garage door opener was fried, as was the house intercom system and answering machine, and all ground fault sensors were tripped.
Presently, I use only unplugging everything in electrical storms.
Presently, I use only unplugging everything in electrical storms.