Samsung UE46f7000 Volume levels go up and down
:I have a new Samsung UE46f7000 TV. The sound is connected to my 2 channel amp via optical out, dac and then stereo phono/rca cables to the amp. The problem I have is that the volume goes up and down on it's own. It seems to settle down after a while. Then whenever I change source again the same thing happens. I have spoken to John lewis technical and all they could suggest was the auto volume settings but this makes no difference and in fact the setting is unusable whenusing external speakers. Any ideas why the volume is going up and down on it's own?