They way i understand it is by code you need to have a common ground for the entire system at the main box. That being said some people use a seperate star ground direct from the outlets, which i think i get but not enough to discuss it..I'll leave that one for the experts. I had used a seperate ground rod driven through the basement slab as an additional ground. My dedicated line sub box was tied to the main box and thus shared a common ground there. IT sounded really good in that configuration. However some helpful guys over at audio asylum illustrated how a difference in potential between the two grounds could cause a lightning strike to choose a path of least resistance through my system. I live in the midwest so needless to say I removed the second ground. I did suffer a near lightning hit last spring and got away with some fuses and a few power amp tubes, I don't want to think what the damage could have been. I have also heard that a secondary ground can cause ground loops.
5 responses Add your response