I have an Onkyo 602 recevier and Comcast Cable HD box, Onkyo 702 DVD player. My problem is that when I change channels on the cable box (hooked up with digital optical cable to Onkyo) that I hear a faint pop sound in my speakers. It also makes the sound when I change DSP modes or when the DVD players is changing surround modes. Do you know of a solution to this or have you heard of this? I would like a solution to it if possible cause I really like the receiver and it works great with this being the one exception. It isn't drum crashing pop just a minor pop but I have a Onkyo LR552 receiver downstairs with the same HD cable box and a Sony ES DVD player and do not have this problem. It is just annoying and I have yet to find an answer after searching for hours on the internet. Some similar problems are to be found but no solutions.