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
Make sure your cable box is set for optimum stereo in it's menu or turned all the way up and never use the volume control on the cable box remote.
I experience the same problem with my 2.1 video set up.
I run DirecTV digital out to a MD10 virtual surround DAC/PRO decoder.
One channel will disappear and come back if I raise the volume a little.
I use the analog pass through on a Parasound AVC 1800 for the Left - Right - Sub output of the MD10.
My next step is to lower the level controls on the Parasound amps in order to raise the volume level higher on the pre/pro and see if this solves the issue.