DENON 1613 noise or feedback?

Welcome to AVS Forum.

Is the AVR connected to a surge protector? Does the issue occur with the Tuner selected as well? Did you run AUTO SETUP (Audyssey)?

Also, many of the current model AVRs generally have their own Owner's thread to discuss issues and such. The Denon AVRs are grouped into single threads, both last year's XX12 models and this year's XX13 models both which are linked in my sig. Review posts #1-6 in each thread for more helpful information.

The "sig" is the dedicated area below each member's post which some choose to use. My sig begins with the link to the Audyssey 101/Setup Guide (which I would also suggest you read as doing an Audyssey setup will most likely result in a much better setup than you'll be able to do manually ... I'll also add that if you're not familiar with Audyssey, it will set a system as the "mixer" intended which may not be what you personally are expecting to hear which is why it's best to review that whole Audyssey Guide to learn as much as you can about the process if you want to do right by your customers that are buying Audyssey featured AVRs). So to answer your question ... each of the Denon XX12 and XX13 model thread links in my sig have helpful information in the first 6 posts (ie. 1-6). If you click on those links, you'll be taken right to those threads.

Can't address the HAM radio or new wiring; however, she can take the Monster surge protector out of the mix and plug the AVR directly into the wall socket to see if the same "heartbeat" sound is heard. Otherwise, I would suggest you putting another AVR in it's place to see if you get the same results to determine if the 1613 must be replaced or not.

It's not my Audyssey guide, rather a list of the most common 50+ asked questions in the Audyssey thread put together by one of the more frequent Audyssey posters. A conditioner is likely only really needed if there are big power surges and or RFI/EMI noise issues. I'd try to rule out the AVR as the cause and if not, then as suggested, try resetting the microprocessor, noting that doing so will also reset all settings to their factory level defaults and require running Audyssey again.

The Audyssey Guides are likely to provide far more beneficial (and more practical) information than was learned in your earlier course, so be sure to review the Setup Guide and the FAQ/101 guide as well. Also, as long as you're going to redo Audyssey setup (noting that all 6 positions should be used with positions 2-6 simply being within a 2'-3' radius of the #1 position rather than where someone actually sits), you might as well reset the microprocessor as well.

Sure. Also feel free to post any setup/troubleshooting issues in the respective Denon AVR-XX12 and AVR-XX13 Owner's threads linked in my sig.