These products either lack performance requirements or don't hold engineering to them.
I was considering replacing an older Onkyo used as a preamp with the X3700H. That is now on-hold.
Thanks for another great review.
- Rich
The volume control IC has tolerances that may explain why DUTs could measure differently in SINAD by a few dB, though there is definitely something wrong with the noise behavior when HDMI is involved in this case.
Below are the tolerances of SINADs between the volume IC used in the Denon/Marantz and Yamaha's AVRs/AVPs/Integrated amp:
Yamaha A-S801:
BD3483KS2........................... Typ. 0.0004 %, Max. 0.02 %
RX-A3070:
BD34703KS2........................ Typ. 0.0004 %, Max. 0.02 %
Denon/Marantz:
NJU72343AV........................ Typ. 0.0004 %, Max. 0.01 %
The DAC ICs ES9010KS2, AK4458, ES9006 used in such devices all have slightly better SINAD specs so as Dr. Rich of HTHF said before, the volume control IC was usually the bottleneck.
If true (Amir, do you have any opinion on this?), and if you look at the X4700H's SINAD, it is still within the tolerance spec of the NJU72343, and obviously the AK4458 as well.
Also, take a look of Denon AVR/Marantz AVP/AVR publish specs:
AV8805/AV7705's preout..................0.005 %, (that's 86 dB in SINAD)
AVR-X4500H/SR7013
amplifier output....................................0.05 % at rated output
analog input (Direct mode)..............0.005 % (again, that's 86 dB SINAD) at 1.2 V
D/A output..............................................0.008% (1 kHz, at 0 dB)
AVR-X3600H/SR6014
amplifier output....................................0.08% at rated output
analog input (Direct mode)..............0.005 % (again, that's 86 dB SINAD) at 1.2 V
D/A output..............................................0.008% (1 kHz, at 0 dB)
Based on the above figures, so far all the units ASR has measured were within D+M specifications, though depending on interpretation, the D/A output specs would have met or exceeded their specifications only if the internal power amps were disconnected.
Amir, or others who have read the spec sheets and SM's, any comments?
My source of info above were all Googleable, i.e. Rohm, NJR published data sheets for their volume control ICs, D+M's manual.