Why post a dubious comment here?
My own testing has proven otherwise, at least for me, when I test using the best tools I have to work with, including those tools which God gave me.
Please share your testing tests that proved the HDAMs actually delivered the claimed improvements in their AVPs and AVRs (not integrated amps):
On noise, they claimed on one of their website:
So when they couldn’t find a solution to the background noise emitted by traditional operational amplifiers, they took it upon themselves to create one.
Hyper-Dynamic Amplifier Modules are that solution – a combination of exquisite craftsmanship and cutting-edge circuity – and one of Marantz most ingenious inventions to date.
On "signature sound", another claim:
By redesigning the overall architecture of the amplifier circuit, Marantz engineers managed to cleverly incorporate tiny preamplifier modules between the volume control and power amplifier sections. This helps to achieve that signature sound that is at once immersive and expansive.
On overall improvements (I give them/marketing) credit to add the word "subtle":
HDAMs help to make Marantz SR-Series and AV Receivers perform with almost zero background noise, they have also drastically improved the speed at which signals coming into the module are translated into amplified sounds going out.
This means that the output of a Marantz amplifier is a far more responsive, and offers a more accurate representation of the input.
As a result the music sounds fresh and alive, more rich and dynamic, and with high frequencies you can trust. It's yet another way that Marantz helps to make your music sound like it should.
The facts (published specs, and measurements including both Amir's and Gene's) show as @Verdinut
mentioned, if anything, Denon's did better.
Here are some pusblished bench test results that show Marantz (including the AV7705 and 8805) did not do better, in fact typically worse than Denon's AVRs, the only exception is the SR8015 that did measure similar good as the Denon's.
- THD+N (some hate the term SINAD, but ASR provides both for all to see and compare).
- SNR (in some cased, the two yielded very similar results, that show Marantz's are definitely not quieter)
- Harmonic profiles (FFT graphs)
- Multitone tests (32 tones input)
- Pre out linearity
- Frequency response (analog same as expected but on digital, Marantz has a slight roll off due to their choice of a non standard dac reconstruction filter)
So we are not just comparing SINAD, but a multitude of test results.
The power amps did measured practically the same, again as expected because they share the same power amp section and have the same power supply VA ratings.
Now compare their specs, their equivalent models, such as the AVR-X4700H and AR7015 have identical published specs in the owner's manuals.
With the extra HDAM buffer module, it is theoretically possible that Marantz could output higher voltages into lower load impedance, but then again there has been no such indication in any of the measurements googleable.
On the subjective side (I have owned two Marantz AVPs and one vintage separate preamp/power amp pair) I am fine with both brand's products, nothing against Marantz for sure. They all (including several Denon AVRs) sounded the same to me for my listening habits, except the Marantz AVPs are definitely nosier than my Denon AVR-X4400H and a X3400H that I had for two weeks. That's based on ears almost touching the speaker drivers though, from 10 ft away at volume up to -10 even the Marantz were indeed quite, with the HVAC off.