I was able to get my units manufacture date from the Denon support line.
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Denon Replaces AKM AK4458 DAC IC in X4700H and X6700H
- Thread starter bigguyca
- Start date
JSmith
Master Contributor
Especially for an AVR;
So what was this discussion about a few SINAD points and the internal DAC?
JSmith
valerianf
Addicted to Fun and Learning
PCM5102A is what is implemented in the Yamaha RXV-6A that Amir already tested.
If it is the dac chosen by Denon it is a serious downgrade from the AKM dac.
If it is the dac chosen by Denon it is a serious downgrade from the AKM dac.
Especially for an AVR;
View attachment 127980
So what was this discussion about a few SINAD points and the internal DAC?
JSmith
Well, if you figure out the magic combination of settings that give the best performance it should actually measure about 20db better...
Still not great in absolute terms, but at least the noise floor is quite a bit lower, and that's really the most likely thing to be heard.
JSmith
Master Contributor
The right channel/downmix settings were just as important.
Keep in mind not everyone would actually crank the volume high enough to exceed the sweet spot of around 1.4 to 1.5 V preamp output.
At below the 1.4-1.5 V range, SINAD will still be above 95 dB without disconnecting the signal line of the preamp connections to the internal power amps.
Pre out 1.41V will drive the internal amps to 200 W into 8 Ohms and 400 W into 4 Ohms. So yes the DAC's SINAD spec does matter and the PCM5101, or even the 5102 will be a downgrade in terms of the overall SINAD at the pre out, audible or not is a different story.
But they wouldn't confirm if it has the replacement DAC IC and/or wouldn't tell you which one they used to substitute the AK4458?
I'd like to know the answer to this question too. Anyone know if the 3700 DAC has been/will be be replaced?
Correct. They knew nothing about any of that.
Do you know if it was on there previously?
I have no idea.
- Thread Starter
- #36
There is no way to turn the power amplifier sections off in these AVR's. The power amplifiers continue to be powered.
- Thread Starter
- #37
This unit from Cirrus Logic,
CS4365/85/85A | Cirrus Logic
seems one option for a replacement since it offers 8-channels and has voltage output. The specifications are only slightly worse than the AKM unit, and the evaluation board results look promising.
Lower level ESS 8-channel DAC's used in voltage output mode, with an associated loss in performance, are a possibility, but ESS always seems expensive based on distributor prices. Yamaha uses ESS DAC IC's in voltage output mode in some of its higher-level AVR's. In this mode the DAC IC's appear to act as a current source output through about an 800 ohm resistor. The performance is still very nice.
The TI DAC IC's mentioned above (PCM510XA) have been used by Denon/Marantz for years in the zone output circuits. They are much worse performing units than the AKM DAC IC's. The PCM510XA's would represent a definite step down in performance.
Based on Denon/Marantz choosing to "solve" its HDMI 2.1 issues with a wart with a wall wart, the choice of future DAC IC"s is worrying.
Agreed, it is a concern for sure. They did say the peripherals will change too so there is hope that they might go with the ES9006 even if that costs a little more. In terms of SNR and SINAD, it would just be a lateral move anyway.
Macfox
Member
That Cirrus Logic DAC seems to be 24 bit, meaning they'd have to remove 32 bit support and AL32 processing from the spec sheet. I expect them to prefer another 32 bit DAC as to keep negative spec sheet changes to a minimum.
