Congrats man, you’ve just proven surge protectors can’t work. :) You are on your own now, and ignoring the fact that ground and neutral are bonded at the service entrance as well as basic MOV surge protection design.
If you want to have those arguments you are on the wrong site.
I don't know why you are taking on an attitude. A surge protector will work just fine with a product using a 2 prong AC cord. It will protect against a surge voltage on line and neutral with which is the only surge voltage a product with a two prong plug can be damaged by, unless there is another path to ground. You are ignoring the basic principle that current or a surge cannot flow unless there is a path. What does ground and neutral being bonded at the service entrance have to do with a 2 prong plug with no ground connection?
Typical MOV based surge protectors use the ground as a drain. At high surge voltages they attempt to short to ground and sometimes the neutral as well.
A typical MOV based surge protector will short the surge current to wherever the surge voltage exceeds the MOV rating. Line to Neutral. Line to Ground. Even Neutral to Ground. In commercial installations and outdoor installations, the wires are long enough that if there is a surge event, you can even get large voltage differentials between neutral and ground.
When we get speakers back and trace it to blown MOVs from a surge, it is almost always the MOV between line and neutral because the spike isn't from lighting, its from a generator or transformer failure and the surge current is carried on line and neutral.
