You have to read Amir's commentary part carefully in order to decipher what would/could actually mean to you, practically speaking in your own application.
For example, at the 1.2 V level (that's how Denon and Marantz rate their preout), your AVR-X3500H actually measured better, that is 95 dB SINAD for the X3500H, vs only 92 dB for the AV7705.
I am using the AV7705 as an example because it is a prepro, so inherently not affected by the power amp section that isn't there. In practical term, I personally between even SINAD as low as 70 dB is not going to make an audible difference for probably 99% of the home HT users.
Think logically, let's say you have a very quiet room with noise floor between 25 to 30 dB. And let's assume your SR6012 would have SINAD 72 dB, that is 3 dB worse than the AV7705, at 1.2 V.
72+25 = 97 dB, that means under the worst case scenario you won't be able to hear distortions unless you listen to SPL above 97 dB from you listening position. ASR is going to measure a SR6014 soon so stay tune, but again based on the measured AV7705, I doubt it would do better than the X3500H, just to prepare you for the worse so that you may be nicely surprised.
Regarding the DAC, as others mentioned, it is not the bottleneck at all!! So don't worry about it.