Denon Replaces AKM AK4458 DAC IC in X4700H and X6700H

[Oski1997]

Right, it is also inaccurate to say the AVR-X3700H is the counterpart of the SR5015 and/or to say the AVR-X4700H is the equivalent of the SR6015. You did the right thing reading "sources" more carefully and it is a good idea to search out manufacturers datasheets. There is so much hearsay going on.. The 3700 made prior to the DAC IC change did use the 4458 like the higher models. Even the 2600 did, we just have to quality that fact with the manufacture dates.

When I looked at some of the features of the x3700h, I noticed it was missing some of the unique features of the SR6015. For example, I’ve read that the x3700h only supports DSD64 whereas the SR6015 supports DSD128. Is this incorrect? Also, the back panel of the x3700h looks a lot more like the back of the SR5015. Would you disagree? The back panel pics are of the SR6015 and the X3700h (they are not similar). But, if you compare the back panel of the x3700h to the SR5015, I think you’ll see they have a lot more in common. Additionally, the x3700h was not made with a customer in mind who needs a 7.1 input for customers who need a surround multi-channel decoding on an external source. I did some more reading and found that only the x8500HA supports 7.1 inputs. So, the omission of this feature is not specific to the x3700h.

After some thinking, I realized the x3700h is a 9 channel receiver (like the SR6015). This alone aligns the x3700h with the SR6015. Even if other features (both physical and software/firmware) are found in the SR6015 and not in the x3700h.

 

[KMO]

Wow, thanks four this info. So three PCM5100s and one AK4458 for a total of four DACs in the x3400h. The new x1700h has six DACs (but only two are PCM5100). Can the two PCM5100s be powering the Zone2, Network, and Subwoofer in the x1700h? I’m assuming the x1700 will need all of its four PCM5102s for the main channels.

The X1700 only has a single subwoofer channel (two connectors, but they output the same signal). So that will be the 8th signal of the AKM4458 or 4xPCM5102.

The X3400 and X3700 have an awkward number of channels (9 and 13 respectively), so end up leaving some of the DAC channels unused. In the X3400 they put both subs into a separate PCM5100, leaving one AKM4458 channel unused.

 

[Legal-Alien]

Ok, found the DACs.

They are not on the 2nd board underneath the 1st one. There is a vertically fixed board between all horizontal boards and the power-amp section.
After removing the 1st horizontal board you can clearly see the DACs on vertical one.

At least for my 4700, they are still AK4458 (2 pieces).

View attachment 128496

I just want to refer to my post in May this year.
It was not easy for me to find the DAC-Board of my V1 X4700 (pre-may production).
First, I had to remove the first and second horizontal board, then I found the main-zone DACs on the only vertically mounted board.
I don't think a snake camera would help to identify the V2 DACs without removing the upper horizontal boards. Also these boards have multiple connectors on 3 sides, it is a bit tricky to remove them.
The ADC and DACs for Zone 2/3/Network are not on the same board like the main-zone DACs, at least for my V1 X4700.

 

[Oski1997]

I just want to refer to my post in May this year.
It was not easy for me to find the DAC-Board of my V1 X4700 (pre-may production).
First, I had to remove the first and second horizontal board, then I found the main-zone DACs on the only vertically mounted board.
I don't think a snake camera would help to identify the V2 DACs without removing the upper horizontal boards. Also these boards have multiple connectors on 3 sides, it is a bit tricky to remove them.
The ADC and DACs for Zone 2/3/Network are not on the same board like the main-zone DACs, at least for my V1 X4700.

THANK YOU for this information. It is very helpful. I found an ADC with two DACs on one board. I've been wondering where the other DACs were located. At least we now know we cannot use a snake camera but need someone to do an actual tear-down. Someone on this forum had a service manual. But he didn't mention DACs on different boards. Do you know if service manuals would show locations of DACs? After a week of conjecturing, you're the first person to actually have first hand experience with tearing down his AVR so thanks again for taking the time to share your knowledge.

 

[peng]

When I looked at some of the features of the x3700h, I noticed it was missing some of the unique features of the SR6015. For example, I’ve read that the x3700h only supports DSD64 whereas the SR6015 supports DSD128. Is this incorrect?

No that is not correct. Both supports DSD128 for 2 channel and DSD64 for multichannel.

Also, the back panel of the x3700h looks a lot more like the back of the SR5015. Would you disagree? The back panel pics are of the SR6015 and the X3700h (they are not similar). But, if you compare the back panel of the x3700h to the SR5015, I think you’ll see they have a lot more in common. Additionally, the x3700h was not made with a customer in mind who needs a 7.1 input for customers who need a surround multi-channel decoding on an external source. I did some more reading and found that only the x8500HA supports 7.1 inputs. So, the omission of this feature is not specific to the x3700h.

After some thinking, I realized the x3700h is a 9 channel receiver (like the SR6015). This alone aligns the x3700h with the SR6015. Even if other features (both physical and software/firmware) are found in the SR6015 and not in the x3700h.

Your last paragraph is correct, the main difference is, as you already know, multichannel analog inputs are not available on the Denon side except their AVR-X8500H/HA and the AVR-A110.

Aside from that, another hardware difference is the HDAM modules that are found in all Marantz AVR models but not the slimline models such as the NR1711. Some members, including myself, suspect that could be the main reason why Marantz did not do well on the test bench.

You can also compare the following feature and specs that tell you which Denon models compare to closer to Marantz models (for AVRs):

AVR-X3700H, SR6015 specifications:

Both have THD+N 0.08%, 20-20,000 Hz

That's just based on published specs, bench measurements show the Marantz models, if used as preamp processors, did have much higher distortions and noise at higher levels. At lower levels they are not near as bad.

The SR6015 has a little more output, 110 W into 8 ohms vs AVR-X3700H's 105 W into 8 ohms

The SR6015 is slightly heavier, 28.2 lbs vs 27.6 lbs

So the Marantz SR6015 likely has a larger power supply unit, but the difference is negligible. It is also heavier because it has the HDAM modules as well as the 7.1 analog input connections. More hardware, and the resulting larger case obviously would add a little weight too, however small that may be.

On the software side, both offer Audyssey XT32 SubEQ HT, the SR5015 has the Audyssey XT that is not very good at all.

So the two are not identical but really comparable especially in terms of audio specs and as you now know, the SR5015 is quite different.

Since you mentioned "sharing information", and as I mentioned, a lot of information including those based on reliable sources such as the service manuals have been shared on various threads by members. So if you are interested in more details, just go through those threads, or if you wish, I could post a few links that may save you time.

 

[beren777]

Ton of info and conjecture on the teardown of the x3700h, where does that leave the x4700 and 6700h. I think those two receivers will likely be updated the same way due to the discrete DAC boards designs. I have a V2 built x4700h post May 2021. Does anybody KNOW what is being used. I may look into mine with a snake cam if i can get directions on how to do that without taking off the cover and voiding my warranty. Denon straight dodges me, they won't give me an answer. It's the worst case of possum I've ever witnessed, not to mention of the lowest integrity and respect for the folks who give them all jobs.

The cover will have to come off, but that's the extent of it. I don't believe they can legally void your warranty for removing the cover but IANAL. If you smash capacitors with your cam, that's different. Let me verify that I can get pics of the correct spot with the 8mm scope without trouble (now that I know where to look), and if I can, I can lend you my scope if you'll pay return shipping and promise not to break my scope with your AVR.

I am extremely disappointed that Denon is being opaque. Transparency is the best policy, tell people the facts (including any measurement changes). Acting like they have been is a good way to earn a class action suit for fraud.

 

[beren777]

I just want to refer to my post in May this year.
It was not easy for me to find the DAC-Board of my V1 X4700 (pre-may production).
First, I had to remove the first and second horizontal board, then I found the main-zone DACs on the only vertically mounted board.
I don't think a snake camera would help to identify the V2 DACs without removing the upper horizontal boards. Also these boards have multiple connectors on 3 sides, it is a bit tricky to remove them.
The ADC and DACs for Zone 2/3/Network are not on the same board like the main-zone DACs, at least for my V1 X4700.

See my pictures from https://www.audiosciencereview.com/...dac-ic-in-x4700h-and-x6700h.22798/post-992111.

If we're referring to the same vertical board, then yes, it's pretty simple to get an endoscope/borescope in there and get pics of the main zone DACs. I had trouble earlier because I was looking in the wrong place.

 

[SoundsGood64]

See my pictures from https://www.audiosciencereview.com/...dac-ic-in-x4700h-and-x6700h.22798/post-992111.

If we're referring to the same vertical board, then yes, it's pretty simple to get an endoscope/borescope in there and get pics of the main zone DACs. I had trouble earlier because I was looking in the wrong place.

This thread with >300 posts has gotten complex, with references to multiple AVR models. Just a few service manuals are readily available on the internet, and while they show the board layouts, they don't necessarily show precisely how the boards are assembled together. I believe beren777 found it pretty simple to obtain endoscopic pictures of a long row of PCM5102A DACs (that must include Main Zone) in an AVR-X3700H. In contrast, Legal-Alien had to remove boards from a V1 AVR-X4700H to observe two AK4458 for Main Zone and furthermore believes it would be difficult for an endoscope to view the Main Zone DAC board without first removing those other boards. So beren777 and Legal-Alien are referring to two different models, 3700H and 4700H respectively, which may or may not have similar board arrangement. I think we have to take at face value members' respective direct experiences on a specific model and take care not to assume AVR construction is the same across different models. As I said, it's gotten complex, and I post this merely to ensure max knowledge before anyone embarks on an endoscopic journey into unknown (to us) parts of the world.

 

[bigguyca]

This thread with >300 posts has gotten complex, with references to multiple AVR models. Just a few service manuals are readily available on the internet, and while they show the board layouts, they don't necessarily show precisely how the boards are assembled together. I believe beren777 found it pretty simple to obtain endoscopic pictures of a long row of PCM5102A DACs (that must include Main Zone) in an AVR-X3700H. In contrast, Legal-Alien had to remove boards from a V1 AVR-X4700H to observe two AK4458 for Main Zone and furthermore believes it would be difficult for an endoscope to view the Main Zone DAC board without first removing those other boards. So beren777 and Legal-Alien are referring to two different models, 3700H and 4700H respectively, which may or may not have similar board arrangement. I think we have to take at face value members' respective direct experiences on a specific model and take care not to assume AVR construction is the same across different models. As I said, it's gotten complex, and I post this merely to ensure max knowledge before anyone embarks on an endoscopic journey into unknown (to us) parts of the world.

The service manuals have an exploded view of how the AVR/AVP is assembled. This makes it quite easy to see where the main DAC's are located.

The boards with the main DAC's are often called by not-helpful names such as: the side connector board or the front connector board, not the DAC board.

Here is an overview of where the "DAC" boards are located. References are facing the front of the unit. Products grouped together have historically used the same "DAC" board. That may not be true now.

• SR8015 and X6X00H - a horizontal board that is in the stack of boards that has the Digital (HDMI) board on top. Called DAC board. Most recent AKM based board has current sources that drive the opamps the DAC filter circuitry into Class A operation.
• X4X00H and AV770X - a vertical board that is attached to front of the stack of boards that has the Digital (HDMI) board on top. Called the Front Connector board. Most recent AKM based board has current sources that drive the opamps in the DAC filter circuitry into Class A operation.
• X3X00H - a vertical board that is attached to the right side of the stack of boards that has the Digital (HDMI) board on top. Called the Side Connector board.
• X8500H and AV8805 - A horizontal board that is in the stack of boards that has the Digital (HDMI) board on top. Called, helpfully, the DAC board.

The units above, except the X8500H and AV8805, have the Zone and LEGO DAC IC's (PCM5100) on the Digital (HDMI) board in the lower right corner.

o The PCM5100 DAC IC's appear to be very mediocre devices IMO.

https://www.ti.com/lit/ds/symlink/pcm5100.pdf?ts=1638513816395&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FPCM5100

It appears, the output is 2V SE with no external opamp filter circuit evidently required. In addition to the below average THD and noise, the interpolation Filters are poor, see page 15. For comparison the attenuation of the AKM AK4458 stand filter is -80dB, the AK4490 is -100dB.

 

[Oski1997]

The service manuals have an exploded view of how the AVR/AVP is assembled. This makes it quite easy to see where the main DAC's are located.

The boards with the main DAC's are often called by not-helpful names such as: the side connector board or the front connector board, not the DAC board.

Here is an overview of where the "DAC" boards are located. References are facing the front of the unit. Products grouped together have historically used the same "DAC" board. That may not be true now.

• SR8015 and X6X00H - a horizontal board that is in the stack of boards that has the Digital (HDMI) board on top. Called DAC board. Most recent AKM based board has current sources that drive the opamps the DAC filter circuitry into Class A operation.
• X4X00H and AV770X - a vertical board that is attached to front of the stack of boards that has the Digital (HDMI) board on top. Called the Front Connector board. Most recent AKM based board has current sources that drive the opamps in the DAC filter circuitry into Class A operation.
• X3X00H - a vertical board that is attached to the right side of the stack of boards that has the Digital (HDMI) board on top. Called the Side Connector board.
• X8500H and AV8805 - A horizontal board that is in the stack of boards that has the Digital (HDMI) board on top. Called, helpfully, the DAC board.

The units above, except the X8500H and AV8805, have the Zone and LEGO DAC IC's (PCM5100) on the Digital (HDMI) board in the lower right corner.

o The PCM5100 DAC IC's appear to be very mediocre devices IMO.

https://www.ti.com/lit/ds/symlink/pcm5100.pdf?ts=1638513816395&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FPCM5100

It appears, the output is 2V SE with no external opamp filter circuit evidently required. In addition to the below average THD and noise, the interpolation Filters are poor, see page 15. For comparison the attenuation of the AKM AK4458 stand filter is -80dB, the AK4490 is -100dB.

wow, great information. Are you able to share the location of the DACs on the SR6015 and SR7015?

 

[SoundsGood64]

The service manuals have an exploded view of how the AVR/AVP is assembled. This makes it quite easy to see where the main DAC's are located.

The boards with the main DAC's are often called by not-helpful names such as: the side connector board or the front connector board, not the DAC board.

Here is an overview of where the "DAC" boards are located. References are facing the front of the unit. Products grouped together have historically used the same "DAC" board. That may not be true now.

• SR8015 and X6X00H - a horizontal board that is in the stack of boards that has the Digital (HDMI) board on top. Called DAC board. Most recent AKM based board has current sources that drive the opamps the DAC filter circuitry into Class A operation.
• X4X00H and AV770X - a vertical board that is attached to front of the stack of boards that has the Digital (HDMI) board on top. Called the Front Connector board. Most recent AKM based board has current sources that drive the opamps in the DAC filter circuitry into Class A operation.
• X3X00H - a vertical board that is attached to the right side of the stack of boards that has the Digital (HDMI) board on top. Called the Side Connector board.
• X8500H and AV8805 - A horizontal board that is in the stack of boards that has the Digital (HDMI) board on top. Called, helpfully, the DAC board.

The units above, except the X8500H and AV8805, have the Zone and LEGO DAC IC's (PCM5100) on the Digital (HDMI) board in the lower right corner.

o The PCM5100 DAC IC's appear to be very mediocre devices IMO.

https://www.ti.com/lit/ds/symlink/pcm5100.pdf?ts=1638513816395&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FPCM5100

It appears, the output is 2V SE with no external opamp filter circuit evidently required. In addition to the below average THD and noise, the interpolation Filters are poor, see page 15. For comparison the attenuation of the AKM AK4458 stand filter is -80dB, the AK4490 is -100dB.

This is a great post summarizing the board layout across several model series. Wonderful in many ways. I do see the 'exploded view' illustration but just hard to tell how one could fit an endoscope in there for that vertical DAC board, say on the X4_00H, one series in question here. It's difficult for me to infer the actual 3D assembled situation (based on that illustration) and the route by which one could access via endoscope. Not that I'd try, but others wrote they might.

 

[peng]

So beren777 and Legal-Alien are referring to two different models, 3700H and 4700H respectively, which may or may not have similar board arrangement. I think we have to take at face value members' respective direct experiences on a specific model and take care not to assume AVR construction is the same across different models. As I said, it's gotten complex, and I post this merely to ensure max knowledge before anyone embarks on an endoscopic journey into unknown (to us) parts of the world.

Very true, especially now we know the 3700 has the two channel PCM5102A and don't know yet what the 4700 (the one with the DAC IC replaced) though based on Denon.jp website's image, the board(s) are definitely different.

For the previous years model, you can in fact see that the preamp, DACs, power amp boards are extremely similar, including Marantz's except the HDAM parts. Just curious, have you compared those for the X4500H, X6500H, X3600H, SR6012, 6014, 7012, 7013 yet? I am asking because I think you are quite capable of comparing at least the block diagrams and schematics so I would be interested to know if you noticed any significant differences that I might have missed.

 

[Dj7675]

Someone needs to send in one with the substituted DACs. It would be very interesting to see the impact on measured performance. I think many people wanting a good measuring receiver see the reviews done here and will assume that is what they will get when they purchase a new one. This sounds like it won’t be the case. Hopefully one will be sent in by someone one of these days.

 

[peng]

Someone needs to send in one with the substituted DACs. It would be very interesting to see the impact on measured performance. I think many people wanting a good measuring receiver see the reviews done here and will assume that is what they will get when they purchase a new one. This sounds like it won’t be the case. Hopefully one will be sent in by someone one of these days.

May be someone can convince Amir to buy one for the test, auction it if the test results are comparable to past results and refund it if not. I wouldn't mind sharing his out of pocket money if there are enough who would too for a reasonable set limit. It won't be cheap though because he would have to test at least two, preferably 3, to include the 3700, 4700 and the SR6015.

 

[Dj7675]

May be someone can convince Amir to buy one for the test, auction it if the test results are comparable to past results and refund it if not. I wouldn't mind sharing his out of pocket money if there are enough who would too for a reasonable set limit. It won't be cheap though because he would have to test at least two, preferably 3, to include the 3700, 4700 and the SR6015.

I think the best bet is hopefully someone is planning on purchasing one, and has it dropshipped to him. The buyer can then decide if they want to keep it based on the results. I would hate for Amir to get stuck with it if it performs poorly.

 

[peng]

I think the best bet is hopefully someone is planning on purchasing one, and has it dropshipped to him. The buyer can then decide if they want to keep it based on the results. I would hate for Amir to get stuck with it if it performs poorly.

I know, better still if someone would try to convince United Sound's Phil Jones (I think that's his name) to send Amir a 4700 and a 7015, ideally.. One would think they can afford to do such a thing.

 

[Dj7675]

I know, better still if someone would try to convince United Sound's Phil Jones (I think that's his name) to send Amir a 4700 and a 7015, ideally.. One would think they can afford to do such a thing.

That would be ideal. But if Denon knows measurements are worse, they have no reason to do so. I just don't like the idea of consumers reading measurements here and purchasing the units expecting the same performance when that may not be the case. I am wondering if on the current models from Denon/Marantz that have had DAC substitutions that there shouldn't be a note at the beginning of the review, regarding DAC substitution and performance may not be the same as Amir has measured in his reviews.

 

[Oski1997]

That would be ideal. But if Denon knows measurements are worse, they have no reason to do so. I just don't like the idea of consumers reading measurements here and purchasing the units expecting the same performance when that may not be the case. I am wondering if on the current models from Denon/Marantz that have had DAC substitutions that there shouldn't be a note at the beginning of the review, regarding DAC substitution and performance may not be the same as Amir has measured in his reviews.

And if you notice, no one with any authority is saying anything about this. It's only Denon/Marantz owners on forums like this that are speaking up. This is egregious. Does Sound United pay off everyone with influence, including YouTubers? Has anyone seen anything like this with any of the other AV conglomerates like Yamaha and Sony? Do they change DACs (and not change their spec sheets) and then coincidentally forum administrators and YouTubers not say anything? I'm 30-days new to this word of AVR so pardon my ignorance.

 

[beren777]

From Bestbuy's website.

 

[Oski1997]

Per the Denon website (Google translation from Japanese) in Japan in the product information for at least the X4700H and X6700H AVR's:

"The D / A converter IC has been changed since the spring of 2021."

The previous DAC IC in the two products is the 8-channel AK4458. This is a rather significant change. The new DAC IC, brand/model, was not named in the product details.

No change was noted for the AVR's, such as the A110 and X8500H, that use the 2-channel AKM AK4490 DAC IC.

X8500HA and AV8805 now have ESS DACS. A110 still has AK4490. The good news is that the pre-May units (ie x8500h and the others) have the old DACs but unfortunately also have the broken HDMI 2.1 port with a dongle solution.