Recently, my AV-R720 AV Receiver has started to produce a crackling/popping noise out of the front-right speaker. It seems to do it most when first turned on but can also do it when changing from one source to another. It's intermittent and last for a couple of minutes and then seems to vanish for a while.
I've seen this reported elsewhere and it seems to get worse over time and there's never been any conclusion or suggestion of the cause and any potential solutions. It's not even two years old yet so I'm not happy it's failing.