Denon AVC-A1HDA MK3 2011/12 Edition Review

[peng]

What do you mean opamps exists only on front left and right ?

I meant that literally.

The older models, including the ex-flagship AVR-X8500H does not even have those "final stage/buffer" opamps at all for any channels (though I am sure there are good reasons, that it doesn't need that stage to help), the volume IC drives the power amps directly without the NJM8080 opamp in the end stage. They were added probably since the AVR-X3700H (see page 66 in the service manual) and SR6014, and I can confirm it is the same for the AVR-X4800H (page 23 if you have the SM) and the Cinema 40.

Anyway, if, that part of the signal path would look like the following:

You can see that they are there for the FL and FR only, not sure about the reason, and the AVR-X6800H is a different animal so likely different implementation in the final stage too.

If you want to see the schematics, try the following link, someone posted that hard to find source for manuals sometime ago:

https://device.report/denon/avr-x3700h

You won't find the 4800 there I guess it is still a current model so.., I have it because I bought it. Again that part of the signal flow diagrams have not changed from the 3700/4700 to 3800/4800.

Below is a link to some of bugguyca's findings related to the dac, volume ic, switches and the opamps that drives the FL/FR preouts:

Denon AVR-X4700H 2020 AVR Review

They actually a very small company in grand scheme of things compared to likes of Sony, Panasonic, Samsung, etc. But if you compare it, especially if you include Marantz as they obvious share resources now, to Sony and Panasonic's home hifi, HT,(including the pro branch the Denon does...

www.audiosciencereview.com

In the case of Marantz, since the SR6014, it gets even weirder, as even bigguyca didn't seem to know why Marantz would add that opamp behind the HDAMs that are already unity gain buffers:

Marantz SR6014 AVR Review

I understand your point on the feedback effect, but logically speaking I don't buy that because in this case it is an "extra" unity gain buffer stage. If you cut it right out, it would have become a Denon, so the feedback effects should not apply. Denon does not have this stage, so there...

www.audiosciencereview.com

All channels are equals on Denon AVRs (except the 4th sub output on the x6800h, which is handled by one TI5102A like the ones on x3800h/x4800h).
You have a post dac opamps on most implementations, except the cheapest ones which uses a dac which embedded voltage driven output stage.
View attachment 499806

Those diagrams from the video are blurry, but according to the label, the orange block seems to show the opamps NJM8080G that are part of the post dac filters, before going to the volume ICs. So those small blocks that look like opamps are not the final stage that you may be expecting. If you follow the schematics you will see the NJM8080G opamps are only used for the FL and FR as D+M has been for several years.

 

[Vincentponcet]

I meant that literally.

The older models, including the ex-flagship AVR-X8500H does not even have those "final stage/buffer" opamps at all for any channels, the volume IC drives the power amps directly. They were added probably since the AVR-X3700H (see page 66 in the service manual) and SR6014, and I can confirm it is the same for the AVR-X4800H (page 23 if you have the SM) and the Cinema 40.

Anyway, if, that part of the signal path would look like the following:

You can see that they are there for the FL and FR only, not sure about the reason.

If you want to see the schematics, try the following link, someone posted that hard to find source for manuals sometime ago:

https://device.report/denon/avr-x3700h

You won't find the 4800 there I guess it is still a current model so.., I have it because I bought it. Again that part of the signal flow diagrams have not changed from the 3700/4700 to 3800/4800.

Below is a link to some of bugguyca's findings related to the dac, volume ic, switches and the opamps that drives the FL/FR preouts:

Denon AVR-X4700H 2020 AVR Review

They actually a very small company in grand scheme of things compared to likes of Sony, Panasonic, Samsung, etc. But if you compare it, especially if you include Marantz as they obvious share resources now, to Sony and Panasonic's home hifi, HT,(including the pro branch the Denon does...

www.audiosciencereview.com

In the case of Marantz, since the SR6014, it gets even weirder, as even bigguyca didn't seem to know why Marantz would add that opamp behind the HDAMs that are already unity gain buffers:

Marantz SR6014 AVR Review

I understand your point on the feedback effect, but logically speaking I don't buy that because in this case it is an "extra" unity gain buffer stage. If you cut it right out, it would have become a Denon, so the feedback effects should not apply. Denon does not have this stage, so there...

www.audiosciencereview.com

Those diagrams from the video are blurry, but according to the label, the orange block seems to show the opamps NJM8080G that are part of the post dac filters, before going to the volume ICs. So those small blocks that look like opamps are not the final stage that you may be expecting. If you follow the schematics you will see the NJM8080G opamps are only used for the FL and FR as D+M has been for several years.

I don't understand where the discussion is going. Let me restate.
There is necessarily a volume control on each channel in an AVR. Currently it is done in analog domain after the dac output stage with a dedicated an analog volume control chip, and the measurements shows that we don't get the full performance of the dac chips. The volume control chip has a thd+n of 104db so that's what we see max on avr-a1h, when the chip could provide >120db.
And I think we will get a better Sinad if it was done in digital domain in the DAC chip as the ESS does it natively. That's how most high performing standalone DACs are done today.

Note: I think I hijacked the thread. Sorry about that.

 

[peng]

I don't understand where the discussion is going. Let me restate.
There is necessarily a volume control on each channel in an AVR. Currently it is done in analog domain after the dac output stage with a dedicated an analog volume control chip, and the measurements shows that we don't get the full performance of the dac chips. The volume control chip has a thd+n of 104db so that's what we see max on avr-a1h, when the chip could provide >120db.
And I think we will get a better Sinad if it was done in digital domain in the DAC chip as the ESS does it natively. That's how most high performing standalone DACs are done today.

Note: I think I hijacked the thread. Sorry about that.

I simply told you what I know based on info, that the DAC IC's outputs are limited to 2-2.2 V approx., from published info, other than that I don’t have anything else to add. now After your last post though, I want to note one point that the dac for the Denon avrs don’t have >120 dB SINAD except for the A1H and A10H, the X6800H has the ES9017, you can check the data-sheet yourself as I don’t remember the exact number, probably around 110 dB SINAD that is -110 dB THD+N, still better than the vol ic’s -107.95 dB though just barely, and the Cinema 40/AVR-X4800H has the PCM5102A, that has THD+N spec of about -93 dB.

 

[MARCD5123]

Hi guys we have completely gone away from the what this thread is about...It's about the AVC-A1HDA & AVP-A1HDA Models please and a review based on those models only and or any information that can be shared with regards to those models in particular please from other members of community that currently use or had owned these particular models.

Obviously it's great information but why not just create your own thread with regards to the above and let's stick to what this thread was originally created for.

Many thanks ...