I just finished building a Rhoads Concorde with string-through and a Gotoh TOM bridge. I used string ferrules on the bottom and smaller ones on the top. The A string has this really bizarre overtone/harmonic, not quite a buzz, but it certainly doesn't sound a clear A. None of the other strings do this. Dampening the string between the bridge and the top ferrule doesn't make a difference, nor does dampening the string behind the nut. Does anyone have any thoughts as to what is causing this and what can be done to stop it?