Congrats! I assume you got a good price on it, and if you change your mind later, send it to me. For <$500 shipped I'll be happy to take that 70 lb/80-85 lbs boxed thing away from you.
You believe what you believe, I believe maths and science don't lie, best theoretical benefit for such costly implementation is 6 dB reduction in noise from input to output. The typical balanced schemes do not do differential balanced configuration still can achieve very close to that, and the Gene measured the AVP-A1HD, and it did not have better SNR than the AV10, AVM90. Even if it does, say pick the best FFT achievable under a specific condition, such as at 1V, 1 kHz test:
You can see that the AVM 90, at 2 V, still beat the Denon by roughly 6 dB, though both are at the level believed to be below the threshold of audibility, and worth emphasizing that the Denon's SINAD was pulled down by a single 3rd harmonic and such low order harmonic probably have threshold as high as 60 dB or even higher, but we are not talking about audibility but strictly about the fully balanced Denon's measured SINAD against the output balanced Anthem or Marantz flagship. It probably was still the best measured AVR/AVP at the time though, just time time changed lots of things...
I was surprised that the apparently cost no object Denon had the non flagship TI DAC IC, whereas the AVR-5805 did use the TI flagship DAC IC, had the Denon AVP used the same TI chips as its AVR cousin, it would likely have measured as good or better than the AVM90 and AV10, but of course we'll never know, though in theory that would likely be the case.
From Gene's measurements:
Review: The Denon AVP-A1HDCI AV processor is packed with the latest HD audio and HDMI connectivity and THX Ultra2 Certification. It supports 12 channels of audio and is a technological masterpiece.
www.audioholics.com
Gene like that scheme for the added benefit of reduced or eliminated the even order harmonics, but keep in mind to achieve that you need the two legs to be identical and that's a tall order because DAC, volume control, opamps (discreted or IC), even caps and resistors have tolerances so that one is a hit and miss thing, though there will be some theoretical reduction, you still have to go with measurements.
Bottom line, regardless of what all the talks above, AVPs, that would represent the vast majority, that don't implement fully differential/balanced signal path, do not show better SINAD than those (may be a couple more aside from the Denon) that are "fully balanced" on the test bench.
To be clear, I am in
full agreement with you in terms of theory, just not in real world use, where I believe other factors could be far more important and impactful on the final bench test results, let alone in terms of "audibly better/worse".
By the way, I read a lot about that Denon, there were multiple report of failures of some sort at the roughly 8 years mark. That could have been due to the heat generated by the large number of parts used and relatively high bias current, lack of eco kind of gadgets so if you are going to keep it, I would suggest you use an external fan, even if the unit is well ventilated.
