Reasonable by whose standards? Here are the specifications from AKM on the DAC chip in there:
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And this is what I measured:
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You want to tell me how I am supposed to be OK with a product that costs thousands of dollars but leaves 20 dB of the DAC performance on the table?
Because you tested it as a preamplifier putting out 4 volts. You did not test (and probably cannot test it) as a stereo DAC with 2V lineouts straight off the chip, and it is not intended to be used that way. But that's all a standalone DAC has to do.
I think it's important to maintain a basis for comparison. I had trouble finding a test of any preamplifier that measured as well as you're demanding the Denon measure to avoid "leaving DAC performance on the table". Almost all of them will. But... Then I found a few--very, very few. For $28,000, you can buy the SimAudioMoon Evolution. Or the mbl 6010d for, uh, $24,000. On the cheap end of the spectrum, you can get it out of a Benchmark DAC3 Pre, for $2000. All of these are just two channels, and the Benchmark isn't a very full-featured product by any stretch.
For comparison's sake, Archimago's measurements of his Onkyo NR1009, which was about a $1400 piece of equipment, came in around .03% THD+N. So you are getting something for the extra money. You're just not getting a level of performance of a separate standalone DAC.
My complaint is the comment that companies are "getting away" with releasing products that leave performance on the table. Many purveyors of kilobuck crap do, but that isn't clear here. It's perhaps a minor complaint, but I don't think it's fair
in context. Now, if this was a $6000 stereo DAC that measured like this? Yeah, we should all be spitting nails. But it isn't. If memory serves, there are eleven AKM4490 DAC chips in this thing. There are full video processing circuits. There is room equalization. There are no fewer than
seventeen preamplifier channels in this thing, with (if handled in the analog domain), just as many volume controllers. There's a phono preamp, Bluetooth, etc, etc. That you can get so much, with so little distortion (all but measurably transparent at 1kHz on CD audio), for such a small price is amazing. To see if the distortion really is too high, or if Denon is "getting away" with anything, you would need to measure a product that costs about $1500, to see if that does worse, and then $800 to see where that lands. If it does the same or better, then ... yeah, Denon is getting away with charging for not much more than a few extra processor channels and balanced outputs. Of course, that would also mean that Benchmark is completely screwing everyone (which I don't think is the case). Else, this is simply an astonishing value for the money.