Denon Replaces AKM AK4458 DAC IC in X4700H and X6700H

[beren777]

PCM5102A is easy to use. Given the poor performance their team extracted from the AKM chip, it's possible this updated version actually measures better. The difference is likely inaudible, in any case.

Likely inaudible, but the theoretical maximum SINAD of the PCM 5102A is -93dB if I'm calculating it correctly from the IC spec sheet. This is lower than the measured -96dB of the AKM-based unit. The v2 DAC will measure worse, not better, but I agree it may not be audible.

 

[peng]

Likely inaudible, but the theoretical maximum SINAD of the PCM 5102A is -93dB if I'm calculating it correctly from the IC spec sheet. This is lower than the measured -96dB of the AKM-based unit. The v2 DAC will measure worse, not better, but I agree it may not be audible.

Agreed. I said the same before, that if it is the PCM5102A (and now we know it is), it would be like you said... The best it could do on Amir's bench would be 93 dB SINAD at 2 V, likely a little less, assuming there is no other bottlenecks in the V2.

 

[SoundsGood64]

As an aside, I've never been sure why the Denon AVRs need a separate 'network' dac chip, if anyone knows why please comment! There is a separate network dac despite two lines of evidence that the HEOS (Denon network) will use the main zone dac (such as AK4458). First is that service manual digital block diagrams for several AVRs show a pathway from HEOS to the main zone dac (and even the zone 2 and zone 3 dacs). Second, Amirm's measurements using HEOS (Denon network) are very comparable to digital input via coax or HDMI suggesting use of a common electronic pathway. Background info: The AVR-X6400H used 3 PCM5100 for network, Zone 2, and Zone 3 plus 2 AK4458 for main zone. The DRA-800H (2ch AVR) uses AK4458 (main zone) plus network PCM5100 plus 'downmix' Zone 2 PCM5100.

Made a new thread concerning this question, titled:
What is the purpose of a dedicated 'Network DAC' in AVRs?

What is the purpose of a dedicated 'Network DAC' in AVRs?

Denon Audio-Video Receivers (AVR) can play audio files (flac, dsf, etc) over the network and also can play a different digital source in each designated 'zone'. Each zone is assigned a specific digital-to-analog chip (DAC) or set of chips. For example, the AVR-X6400H has for the main zone two...

www.audiosciencereview.com

 

[peng]

Made a new thread concerning this question, titled:
What is the purpose of a dedicated 'Network DAC' in AVRs?

What is the purpose of a dedicated 'Network DAC' in AVRs?

Denon Audio-Video Receivers (AVR) can play audio files (flac, dsf, etc) over the network and also can play a different digital source in each designated 'zone'. Each zone is assigned a specific digital-to-analog chip (DAC) or set of chips. For example, the AVR-X6400H has for the main zone two...

www.audiosciencereview.com

If I remember right, for the AVRs, there is no dedicated dac for network for the main zone, network would use the same one. The two channel PCM5100 is for the secondary zones use only. Again, that's if I remember right. You can look at the available service manuals yourself just to be sure.

 

[SoundsGood64]

Given the visual confirmation here of DAC substitution, perhaps it is possible for an individual to test whether their specific AVR has had its AK4458 replaced with a set of 2ch PCM5102A DACs--but without opening the machine. The PCM5102A spec sheet does not indicate it processes DSD, whereas the AK4458 can. When connecting a super audio CD (DSD) player with HDMI out to the AVR, the player can be set to send DSD over HDMI, or else do DSD-to-PCM transcoding in the player and send PCM over HDMI. Many Sony blu-ray players and the Oppo players do this for example. A Denon receiver capable of processing DSD over HDMI should display "DSD Direct" on its front panel when set to 'Direct', according to page 134 of the AVR-X3700H manual (written when AK4458 was in use). One doesn't even need a Super Audio CD to do this, as free DSD files can be obtained and then played using the USB on the DSD-capable blu-ray player. I do not know what would happen though if the same player with the same setting was then connected via HDMI to an AVR-X3700H or other AVR that had all PCM5102A instead of a main zone AK4458. When playing DSD over HDMI this DAC substitution should result in the display no longer indicating "DSD Direct". The sound might be silent, or hopefully at least the engineers would have had the modified AVR do DSD-to-PCM transcoding so that the PCM5102A could process the digital signal. So at least here might be one possibility of determining the DAC state without opening the machine. Not 100% sure it would work, but a possibility at least. LATER EDIT: POST 267 shows this isn't going to work.

 

[SoundsGood64]

If I remember right, for the AVRs, there is no dedicated dac for network for the main zone, network would use the same one. The two channel PCM5100 is for the secondary zones use only. Again, that's if I remember right. You can look at the available service manuals yourself just to be sure.

Hi peng good to post with you over here too and thanks for your reply. It's weird. The AVR-X6400H service manual explicitly shows (in bold red) the audio signal going from the Network module to Main Zone DAC, Zone 2 PCM5100, or Zone 3 PCM5100. And in the very same diagrams, there lies an additional "Network DAC PCM5100" that isn't highlighted in red. If there are 'n' zones there seems to be n+1 DACs, the plus one being the designated "Network DAC". Mystery.

 

[beren777]

Given the visual confirmation here of DAC substitution, perhaps it is possible for an individual to test whether their specific AVR has had its AK4458 replaced with a set of 2ch PCM5102A DACs--but without opening the machine. The PCM5102A spec sheet does not indicate it processes DSD, whereas the AK4458 can. When connecting a super audio CD (DSD) player with HDMI out to the AVR, the player can be set to send DSD over HDMI, or else do DSD-to-PCM transcoding in the player and send PCM over HDMI. Many Sony blu-ray players and the Oppo players do this for example. A Denon receiver capable of processing DSD over HDMI should display "DSD Direct" on its front panel when set to 'Direct', according to page 134 of the AVR-X3700H manual (written when AK4458 was in use). One doesn't even need a Super Audio CD to do this, as free DSD files can be obtained and then played using the USB on the DSD-capable blu-ray player. I do not know what would happen though if the same player with the same setting was then connected via HDMI to an AVR-X3700H or other AVR that had all PCM5102A instead of a main zone AK4458. When playing DSD over HDMI this DAC substitution should result in the display no longer indicating "DSD Direct". The sound might be silent, or hopefully at least the engineers would have had the modified AVR do DSD-to-PCM transcoding so that the PCM5102A could process the digital signal. So at least here might be one possibility of determining the DAC state without opening the machine. Not 100% sure it would work, but a possibility at least.

My 3700H, a random Pink Floyd SACD from my Sony UBP-X800M2 over HDMI. Sounds fine as well.

 

[Oski1997]

It's only been shown/discussed that the pcm 5102a has been used on the Denon x3700h, which was in fact not mentioned in the dac ic controller notice on denon japan. While i can understand his wanting to confirm what was there on his model. It is why i have not dropped the issue in what has been used in the other models in denons range. Thanks for your input beren.
That snake camera idea was really creative.
Given this is the highest model Denon that doesn't use the discrete board processing dac, it is all kinds of possible that this is a solution only for the lower half of denons X range.

I've seen the inside of the new 2021 x1700h (with three HDMI 2.1 inputs and one HDMI 2.1 output). It uses four PCM5102a DACs and two PCM5100A DACs.

 

[Oski1997]

@beren777 In the top photo I can see two PCM5102A DAC chips, but it's hard to count them in the bottom photo. How many PCM5102A DAC chips are there? (Perhaps you have another photo or remember from your scope trip.) The reason I ask is that there might be one PCM510x series DAC each for 'network' and Zone 2. To replace an 8ch AK4458 I suppose that would be four 2ch PCM5102A. So then the total would be 4 (main zone) plus 1 (network) plus 1 (Zone 2) for a total of 6. Anyway, if there are more than 2 PCM5102A DAC (2 account for Zone 2 and network) then those additional (4?) are likely main zone substitute for AK4458. If confirmed, then use of PCM510x series dac for main zone would mean that the AVR-X3700H can not do direct DSD via HDMI, whereas the manual indicates that it can (based on use of DSD capable AK4458 dac).

As an aside, I've never been sure why the Denon AVRs need a separate 'network' dac chip, if anyone knows why please comment! There is a separate network dac despite two lines of evidence that the HEOS (Denon network) will use the main zone dac (such as AK4458). First is that service manual digital block diagrams for several AVRs show a pathway from HEOS to the main zone dac (and even the zone 2 and zone 3 dacs). Second, Amirm's measurements using HEOS (Denon network) are very comparable to digital input via coax or HDMI suggesting use of a common electronic pathway. Background info: The AVR-X6400H used 3 PCM5100 for network, Zone 2, and Zone 3 plus 2 AK4458 for main zone. The DRA-800H (2ch AVR) uses AK4458 (main zone) plus network PCM5100 plus 'downmix' Zone 2 PCM5100.

I've seen the inside of the new 2021 x1700h. If they are similar, this post-May x3700h either uses five PCM5102a DACs and two PCM5100A DACs OR seven 5102A DACs. Either way it would be a total of seven DACs. I agree with you, the two PCM5100A are probably used for the zone2 +network and the five PCM5102As are used for the main zone. The 2020 pre-May x3700h I saw had one AKM5358BET and two PCM5100A DACs. But, I've been told that the AKM5358 is a ADC and not a DAC. So I'm not sure which DAC is used but nothing was around the area where the PCMs were located.

 

[SoundsGood64]

My 3700H, a random Pink Floyd SACD from my Sony UBP-X800M2 over HDMI. Sounds fine as well.

Ok, we'll have to disregard that idea I proposed in post 265 to use the Direct DSD feature to distinguish the AVRs with main zone PCM5102A vs AK4458. Like many nice ideas they don't turn out ! So then I wonder what the 'DSD Direct' in the photo is indicating? I suppose it could just be indicating the receipt of DSD via HDMI yet with DSD-to-PCM transcoding, versus DSD-to-analog conversion by PCM5102A (although the spec sheet does not indicate DSD capability). Perhaps this discussion is getting a bit in the weeds...

 

[KMO]

It appears the 5102A may have DSD capability, even though the main datasheet doesn't say so. I can see a couple of references to projects using it.

http://jlsounds.com/uploads/PCM5102_board.pdf (although elsewhere on the site it says it can't)

dsd playback on pi b rev 2 5102A dac

Very new to this posting malarkey. Not even sure if this is the correct bit of the board… Recently found a use for my old RPi B (rev 2) by adding a £14 DAC from ebay “HIFI DAC Audio Sound Card Module I2S interface for Raspberry pi B Version”...

community.volumio.org

This doesn't seem totally far-fetched - it's part of an overall family that includes some with DSD support, usually under software select control. Maybe this contains a core that's capable of it if you know the secret config. Although I don't see any spare "reserved" pins that might initiate a format selection, nor anyone else revealing the secret config.

Assuming the 3700H did originally use the DSD capability of the AK4458, switching to PCM transcoding for "DSD Direct" for the 5102A would have been quite a software pain, not to mention being the sort of thing to wind up customers even more, so they would have wanted to try to keep DSD if possible.

But then, maybe the 3700H never really actually did true DSD direct? Can't find anything definitive saying it did.

 

[Oski1997]

It appears the 5102A may have DSD capability, even though the main datasheet doesn't say so. I can see a couple of references to projects using it.

http://jlsounds.com/uploads/PCM5102_board.pdf (although elsewhere on the site it says it can't)

dsd playback on pi b rev 2 5102A dac

Very new to this posting malarkey. Not even sure if this is the correct bit of the board… Recently found a use for my old RPi B (rev 2) by adding a £14 DAC from ebay “HIFI DAC Audio Sound Card Module I2S interface for Raspberry pi B Version”...

community.volumio.org

This doesn't seem totally far-fetched - it's part of an overall family that includes some with DSD support, usually under software select control. Maybe this contains a core that's capable of it if you know the secret config. Although I don't see any spare "reserved" pins that might initiate a format selection, nor anyone else revealing the secret config.

Assuming the 3700H did originally use the DSD capability of the AK4458, switching to PCM transcoding for "DSD Direct" for the 5102A would have been quite a software pain, not to mention being the sort of thing to wind up customers even more, so they would have wanted to try to keep DSD if possible.

But then, maybe the 3700H never really actually did true DSD direct? Can't find anything definitive saying it did.

The original x3700h (serial number below 70,000) had one AK5358 (24-bit 96kHz 102db). It’s Marantz counterpart (the SR5015) also used the AK5358. The x4700h and it's Marantz equivalent the SR6015 both used the AK4458 (32-bit 768Hz 115db). I have read that the post-May (serial# above 70,000) SR6015 continues to use the AK4458 but the post-May x4700h was downgraded to the PCM5102 DAC. But this has yet to be confirmed by a visual teardown. I agree with you, I have also read that the PCM5102A has DSD64 (via HDMI) support. The AK4458 supports DSD128 (via HDMI). Also, I agree with you that the x3700 never supported native DSD (but converted the signal) because the AK5358 doesn't have native DSD. But at least it accepts some form of DSD64 so you can play the files via a USB but not from a SACD player.

PS - I've been told that the "AKM5358BET 9S002" is not a DAC but an ADC. There was nothing around the PCMs I saw so I don't know where the DAC would be located.

 

[KMO]

Also, I agree with you that the x3700 never supported native DSD (but converted the signal) because the AK5358 doesn't naive DSD.

Aha. (They really shouldn't be saying "DSD Direct" then. That always used to be distinct from "Direct", with the meaning that the DSD was going to the DACs.)

And that in turn means that changing the 4700 and up to remove the real DSD direct for the PCM5102 would be less of a pain - the software would have already had the function for the 3700. Assuming that the 4700 even had real DSD direct. Maybe all 700-ranges only ever did PCM for simplicity.

 

[Oski1997]

Aha. (They really shouldn't be saying "DSD Direct" then. That always used to be distinct from "Direct", with the meaning that the DSD was going to the DACs.)

And that in turn means that changing the 4700 and up to remove the real DSD direct for the PCM5102 would be less of a pain - the software would have already had the function for the 3700. Assuming that the 4700 even had real DSD direct. Maybe all 700-ranges only ever did PCM for simplicity.

It is my understanding that the x4700 and the x6700 both support native DSD64. So you can play files from a USB or play a CD from a SACD using these two AVRs. We’ll, at least the units with the AK4458. I’m not sure what the new PCM5102a can do natively. But you should be able to at least play a converted version of DSD64 from a USB on the x3700. But the x3700 cannot receive a signal from a SACD player. It's only what I've read. I actually have never tried this on either system (I'm 3 weeks new to the AVR world) so maybe someone who has can chime in.

 

[KMO]

The X3700 can receive DSD over HDMI - see the indicator display above. But from what you say it will be converting to PCM due to non-DSD DACs, despite saying "DSD Direct".

(Maybe the DSD in the text there is a sop to the fact there's no separate "PCM" and "DSD" input indicator as older/higher-end AVRs have. They would be showing the "DSD" input light, but no DSD in the text).

 

[Oski1997]

The X3700 can receive DSD over HDMI - see the indicator display above. But from what you say it will be converting to PCM due to non-DSD DACs, despite saying "DSD Direct".

(Maybe the DSD in the text there is a sop to the fact there's no separate "PCM" and "DSD" input indicator as older/higher-end AVRs have. They would be showing the "DSD" input light, but no DSD in the text).

That is my understanding. The non-DSD DAC (the AK5358 24-bit 96kHz 102db) found in the x3700h is converting the signal to PCM.

 

[wask]

From #269.
No one uses ADC AK5358 like DAC. No?

 

[KMO]

From #269.
No one uses ADC AK5358 like DAC. No?

LOL! That'll teach me to read sources more carefully. Yes, that part's an ADC. It's not a DAC. (I did google and found the datasheet. Scanned it enough to confirm the basic format parameters stated above, but not enough to actually spot it wasn't a DAC!)

Which means the last few posts are basically nonsense. Previous posts suggest the 3700 used the 4458 like higher models, so could have been capable of true DSD Direct.

 

[peng]

LOL! That'll teach me to read sources more carefully. Yes, that part's an ADC. It's not a DAC. (I did google and found the datasheet. Scanned it enough to confirm the basic format parameters stated above, but not enough to actually spot it wasn't a DAC!)

Which means the last few posts are basically nonsense. Previous posts suggest the 3700 used the 4458 like higher models, so could have been capable of true DSD Direct.

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.

 

[Oski1997]

From #269.
No one uses ADC AK5358 like DAC. No?

Does that mean that the main DAC is somewhere else away from these three found in the x3700h and the SR5015? If yes, where can it be found?