lately i had two clone boxes Dm500s which give a buzzing sound when on (audio tro RCA) When in standby mode and LNB is off the buzzing disappears. This sound intensifies and changes in pitch when rotor is moving. The 2 boxes ended up with faulty tuners. I have another clone now which does have the same buzz but very faint, however I have noticed that this buzzing disappears if I use the TOSLINK (optical out). To date this clone box is not giving me any trouble with tuner (one week usage) Anyone has had the same or similar issue??