It sounds like you were having issues with a ground loop hum, and the factory suggested that you try to float the ground, which caused a loud bang that took out your speakers? It sounds to me like you have major troubles with your electrical service. Have you had a licensed electrician inspect your home service and outlet?
Floating the ground should not result in a tremendous blast.
Maybe Al will be able to drop in and add some of his expertise.
Floating the ground should not result in a tremendous blast.
Maybe Al will be able to drop in and add some of his expertise.