At this point I thought it is time to not repeat things myself, but take a look of what some experts have commented on related topics supported by measurements and related theories, all pointing to while they could be audible difference between the gear mentioned on this thread so far, if the sort of night and day kind of differences were heard, there would likely be other factors than the dac, preamp, amps.
In his review on the Yamaha CX-A5200, Gene commented:
While 23dB sounds like a really big number, it's important to note that the overall distortion level is still quite low for the CX-A5200 model and below the threshold of audibility in my testing. While I'm not happy about this result, as it certainly is NOT State-of-the-Art (SOTA), it never diminished my enjoyment of this product even during my critical listening sessions.
And he obviously referred to the Yamaha's measurements below:
Yamaha CX-A5200
CX-A5200:
Purple: Unbal -88dB @ 1kHz
Blue: Bal -72dB @ 1kHz
Note that -72 dB is 0.025%
and then in his review on the little AVR-X3300W, he also commented on distortions vs audibility:
AH review on the Denon AVR-X3300W
".....At 1Vrms, the FFT of the AVR-X3300W pre-out was squeaky clean, with the 2nd-order distortion 97dB below the fundamental. That is an excellent result and well below audibility...."
and he commented on distortions again in his more recent review on the Marantz SR8012:
AH review on the SR8012
"..At 1Vrms, the FFT of the SR8012 was good but I was surprised at the 3rd order harmonic byproduct that was about 3dB higher than I observed on the
Denon AVR-X3300W prior but it was very low at .0018% THD. ..."
So while AH has not review any Denon AVR since 2017, you can put the 2 and 2 together and have an idea of what he considered the threshold of audibility.
The fact that the AVR-X4700H's THD+N at 1 kHz measured by ASR was so much lower than the 3 he measured above, if those 3 cleared the threshold, it is hard to imagine the X4700H would not.
Just for reference, Gene also reviewed the improved SR8015 recently:
AH review on the Marantz SR8015
Its distortions much lower, comparable to that of ASR's numbers for the AVR-X4700H.
Finally, our resident audio expert Matthew Poes on distortions:
Audio Distortion: What is It and Why Should You Care? | AV NIRVANA
If you don't have time, please at least read the last 4 paragraphs, starting from the one on "Masking".
All of the above are easy to read, there are many more technical articles if any is interested, I have downloaded and book marked many good ones.