The best solution for you would be to add a 2ch amp and use your receiver as the preamp. I just did this with my Yamaha RX-A1000. Fortunately your Denon has HDMI ARC, a 12v trigger, and pre-outs for the mains which is all you need. I really wanted to keep a single remote and have everything turn on and off with a single button which is where ARC and the 12v trigger come in handy. There are hundreds of 2ch amps you can find in your price range. It won’t be hard to significantly improve upon the amp section of your Denon.
I was limited on space so I went with a Linn AV5105, which is an incredible used bargain in the 400-500 dollar range. They were originally around $1800-1900 new.
I was limited on space so I went with a Linn AV5105, which is an incredible used bargain in the 400-500 dollar range. They were originally around $1800-1900 new.