crackling noise. goes away when volume is upped

I have this issue that sometimes the volume starts crackling up and disappearing. It could always be rectified by raising the volume (it reappears solidly) and then lowering it to a normal level again or by changing a channel and going back. This happens in the TV mode only and I am wondering whether to blame a cable box (though it happened with a cablevision's one and is now happening with verizon's one as well), the amp (Sherbourn 5/1500A) or the pre-amp (Denon AVP-8000).

thanks much