Do not know the answer to your question, but can tell you that Jolida takes good care of their customers so just give them a call.
turned out to be dirty power. My roomate came to me with a complaint of the same type coming from his completely seperate system. The problem went away after a while, but now that I know how much of an affect bad power source can have I am going to get a balanced power supply. I can spend about 500 if anyone has any suggestions