I bought the unit in Feb 2020. I did not try the Height2 channel until last week. My guess is it may have been damaged when I received it? However, the Height1 channel was in use and just started crackling so who knows?
I understand receivers break. But, not usually so quickly. I never ran it louder than 60 on the volume. By any measure babied. However, I don't understand how Denon can sell product and never answer their phones. That's not a practice I can support.
I'm told since Denon merged into a huge conglomerate service and quality control have deteriorated. I'll send it in for repair and see how they do. I have learned never to buy anything expensive from Denon as their telephone support is non-existent.
I think phone support stopped working well since Covid, but their customer website does respond in a couple days, that's as far as I know but could be wrong. D+M's are not the only one that have failed often enough to get noticed via feed backs on forums, but I don't think you need to shy away from them in future. If you do a search, even right here on AH, you will find issues with Yamaha, Onkyo and others too. To play safe, test everything within the returnable period should improve your odds because such products typically would last for years and would fail within 30 days if they are to fail.
Chance of failures of electronic products as complicated as AVP/Cs and AVRs is one good reason I started recommending against AVP/Cs as one can limit their loss on such potential tough luck failures. In practice, I have seen no evidence of AVP/Cs performing better, the only thing they bring are the balanced connections, and it is a myth that they would improve anything for most home use. That's of course based on the fact that if one can wait for the often deeply discounted street prices that don't seem to happen with AVP/Cs, and only since the price of the latest AVP/Cs seem to have gone through the roof in the last couple years.
