MOV's will wear out if they are constantly "hit" with spikes and surges. However If there is a choke in front of the MOV then the choke will limit the peak spike energy and extend the life span of the MOV. If I remember correctly the Tripplite Isobar Ultra series does this. I think the real question is how many of us in residential areas are hit on a consistent basis with spiking. Any ideas?
d.b.
In principle, all of the time. The question is how large are these spikes and of course, how long do they last. Usually, they are well into microseconds, typically 5-10 uS, but there are many of them.
Also, if you add a choke in front of the MOV, you kill the dynamics kinda dead. Chokes are like women - impossible to live with, worse wihtout them.
I have to stop now, because of my changed status. This afternoon, I became a manufacturer, since my company registration papers have come through.
Therefore, brother audiophiles, henceforth my comments regarding power line filters will be most lacking.
Cheers,
DVV