I think this may be related, so, here goes. I bought an 80 year old home 5 years ago. Lets just say everything was suspect from plumbing to electrical. In sight of that, I replaced everything. In the electrical, I knew that a good ground was an essential start. Fortunately, the water well housing went 25 ft. down, and was a very heavy duty type pipe. What could be better than that? In addition to this, I followed procedure, at least in part, to how we used to ground the radio sites for the phone company. I even added ferrite sleeves every 10 ft. to the dedicated AC line feeding my stereo. In todays enviroment, nothing is overkill.