This article is dedicated completely to Denon AVRX2400H vs. Yamaha RX-V683 comparison. I studied official websites, user reviews and forums to compare these two devices and this article should help you choose the model.
First of all, multi-channel stereo works as it should for every single video source. Secondly, all 8 of the HDMI inputs (7 in the back, 1 in front) are HDCP 2.2 compliant, meaning you can pass through full, glorious 4K HDR on every single HDMI input.
I would say it has a bit more of a refined sound. I'm running a 5.1.2 Dolby Atmos-capable speaker setup (the sub is a Boston Acoustics 10"). This same setup through the Denon sounds, as I said, more refined - the overall tones when watching UHD and HD Blu-rays.
The bass coming from the sub doesn't sound quite as hard, and the overall EQ just seems a bit more balanced. Also, this Denon seems to do a better job with Atmos soundtracks--noises get thrown around the room a lot more efficiently. This is probably a result of the longer auto-calibration process that you perform during initial setup (the Denon measures speaker sounds from 8 different positions). The Denon sounds more brittle when playing music.
This new Yamaha RX-V683BL really rocks. I love the fact that it can be set up via an Android app on my phone. It has really clean sound. I only have one complaint: for whatever reason, they didn't put a switched outlet on the back. This receiver only supports ARC at the moment, though a firmware update may be able to change that. eARC is expected to hit the mainstream market along with HDMI 2.1, this unit is still HDMI 2.0.
How to choose between them?
If you need more output power, then consider buying Yamaha RX-V683. Unless, you have Apple lossless audio files or you need a DTS neural:X decoder.
However, it has many additional features, like Deep Color or Bi-amplifying. If you need a device that can play almost any kind of audio files (except for AIFF), then Denon AVRX2400H is right for you. Moreover, it can decode DTS neutral:X, but it has less additional features.
Yamaha RX-V683BL overview
Denon AVRX2400H overview
The best receiver is Yamaha RX-V683BL. Check Yamaha RX-V683BL price at Amazon