I just bought a Blackstar HT5 metal head and a 1-10 cab. The amp is doing a strange thing. On the distortion channel the low notes sound really buzzy and fuzzy. I almost hear a static electricity kind of thing. The low E string in the lower registers is where is occurs. I plugged it into another cab and same thing. It is doing it with all my guitars too. I wish I could give you a better description of the sound but that is the best I can do. Hopefully someone can help.