Denon AVR-X6700H AVR Review (Updated)

[Fillius]

Does someone know if the issue is/could also be present in the european models (AVC-X6700H)?

They are affected. I have a European model, I'm sending my unit to them to swap out the PCB with the degraded capacitors next week.

 

[ChristianDK]

They are affected. I have a European model, I'm sending my unit to them to swap out the PCB with the degraded capacitors next week.

Very nice to get verified. Who did you contact to get your units serialnumber checked?

 

[peng]

I'm still wrestling with the "musical" part of the sound. It there's a known formula for making the sound more musical? Why is Denon or other companies not using it? I read this all the time from the reviewers, Denon (in my case avr-x8500h) is not as good for the two-channel music listening when compared to Marantz, Anthem and Arcam. The same Sound United team in the mentioned video made me feel like I bought a subpar receiver since Marantz sounds "better" because it has better parts.

I wish they would just go with the numbers instead of such claims that are so subjective in nature. What sounds musical to some, if achieved by intentionally allowing some harmonics to provide the "sound signature" may not be to others.

In you search the internet for such talks, you will see that the 2nd and rd, more so the 2nd harmonics are responsible for the perceived "warmth". The counter argument though then, is that with THD+N lower than 0.01%, is it some easy for people to perceived such warm/musical characteristics even if the 2nd harmonic is in fact the dominant one? T is total, so if 0.01% is the threshold, even if there are only 2nd and 3rd that made up the 0.01%, how much would it matter?

You can compare the FFT of the Denon AVR-X8500H and Marantz AV8805 that shared lots of components and circuitry, and were launched the same year.

To my eyes, most of the harmonics were below -100 dB, the Denon actually has more 2nd harmonics than 3rd than the Marantz, in proportion only though so in a DBT, based on harmonic contents/profiles I just can't see how one can sound "warmer/musical" than the other.

Another factor that could give the different "sound signature" is of course Marantz adopted the slow roll-off filter whereas Denon appeared to have adopted the default sharp roll-off, but that would affect digital inputs and with sampling frequency below 96 kHz only, or am I wrong about this? At least for sure if in direct mode using analog inputs the two should sound the same, all else being equal.

Would love to hear from Amir's take on this.

I thought I should add this one, measured by Marantz, of the SR8015 for comparison. Still don't see those warm/musical harmonics!! So whatever does the trick is something else other than the 2nd and 3rd harmonics.

 

[Bello]

Doesn’t this prove with scientific measurement that capacitor can measurably affect SINAD by large amounts, assuming that Denon is honest about the capacitors (which I have no reason to suspect is untrue?)

Time will bring out the truth. I will personally try to make attempts in finding out (component level if needed) observed, visual component differences.

Some years ago, I purchased a Sony's 66 inch wide screen LCD HD (XBR1) flagship model? They claimed 1080P resolution. No such signal was available at the time. Just 1080i (interlace vs progressive) Fast forward a couple of years, where 1080P had become available. The Sony XBR 1 continued to say "incompatible." A few months after, a customer filed a national class action suite against Sony. Everyone on the sale data base (including me) recovered money from Sony for misleading customers of said specifications.

I'm certain most company's take calculated risk's. In hopes of Not getting caught.

Thanks to AMIRM; This forum will continue to hold there feet to the fire or maybe over RT center of 4700H (joking) for the truth.

 

[bo_knows]

I wish they would just go with the numbers instead of such claims that are so subjective in nature. What sounds musical to some, if achieved by intentionally allowing some harmonics to provide the "sound signature" may not be to others.

In you search the internet for such talks, you will see that the 2nd and rd, more so the 2nd harmonics are responsible for the perceived "warmth". The counter argument though then, is that with THD+N lower than 0.01%, is it some easy for people to perceived such warm/musical characteristics even if the 2nd harmonic is in fact the dominant one? T is total, so if 0.01% is the threshold, even if there are only 2nd and 3rd that made up the 0.01%, how much would it matter?

You can compare the FFT of the Denon AVR-X8500H and Marantz AV8805 that shared lots of components and circuitry, and were launched the same year.

To my eyes, most of the harmonics were below -100 dB, the Denon actually has more 2nd harmonics than 3rd than the Marantz, in proportion only though so in a DBT, based on harmonic contents/profiles I just can't see how one can sound "warmer/musical" than the other.

Another factor that could give the different "sound signature" is of course Marantz adopted the slow roll-off filter whereas Denon appeared to have adopted the default sharp roll-off, but that would affect digital inputs and with sampling frequency below 96 kHz only, or am I wrong about this? At least for sure if in direct mode using analog inputs the two should sound the same, all else being equal.

Would love to hear from Amir's take on this.

View attachment 79316

Hi Peng, I just looked up the harmonic distortion for the 2nd & 3rd harmonics (90db,1m) of my speakers and it's listed as <0.4% 120Hz-20kHz. Question is, would my speakers be able to resolve this difference, and would my ears be able to hear it? I would think in the "normal" residential space with minimum room treatments, the listener would be bathing in all kinds of first, second and etc reflections which I would think would make it even harder to hear the direct sound.

 

[RichB]

If I had this product, I would have the unit repaired because it is not up to design specification, there may be other updates, and there is no telling if the less-performant capacitor will have long term issues.

- Rich

 

[peng]

Hi Peng, I just looked up the harmonic distortion for the 2nd & 3rd harmonics (90db,1m) of my speakers and it's listed as <0.4% 120Hz-20kHz. Question is, would my speakers be able to resolve this difference, and would my ears be able to hear it? I would think in the "normal" residential space with minimum room treatments, the listener would be bathing in all kinds of first, second and etc reflections which I would think would make it even harder to hear the direct sound.

<0.4% distortions for 120-20,000 Hz is pretty good for speakers but at what input voltage? I have no idea whether others can hear the difference between the X8500H (use as prepro) and AV8805 with any speakers, but I am quite sure I can't.

 

[617]

I'd like to see some other brands tested personally. Teac, Integra, Yamaha etc.

 

[Dj7675]

If the price is the same I would take the 8500, say for up to $2,500. Otherwise I am more attracted to the 4700 because I thought their overall test results were very good and 7.1.4 is all my room can take unless I move but if I move again it would be to a smaller house.

If one doesn’t need 13 channels, or any of the other features of the 8500 (amp disconnect etc) the 4700 definitely sits in a nice sweet spot for price/performance-front hdmi, auro 3D, good power etc.

 

[junior00027]

I'd like to see some other brands tested personally. Teac, Integra, Yamaha etc.

yes yamaha rx-a3080 and cx-a5200

 

[Fillius]

Very nice to get verified. Who did you contact to get your units serialnumber checked?

I registered my unit with its serial number and proof of purchase on the support site. Then I opened a question against it.

The first response I received said they didn't consider the unit to be faulty. I had to push to get them to offer to replace the board.

 

[peng]

With the updated 6700 measurements included, I updated my comparison table. As always, this is just for quick reference. For accurate numbers please refer to the ASR reviews.



Edit: Fixed one typo and added details.

 

[Kachda]

Doesn’t this prove with scientific measurement that capacitor can measurably affect SINAD by large amounts, assuming that Denon is honest about the capacitors (which I have no reason to suspect is untrue?)

Not quite - this assumes Denon is being truthful, and if so, that a *bad* capacitor is at fault (not cheap). This is different to the audiophile 'fact' that better quality capacitors, even with the same capacitance are better. This is an electrical mystery to me, unless the 'low quality' capacitor is doing something the 'high quality' capacitor isn't.

 

[AllTaken]

If one doesn’t need 13 channels, or any of the other features of the 8500 (amp disconnect etc) the 4700 definitely sits in a nice sweet spot for price/performance-front hdmi, auro 3D, good power etc.

May I ask how you feel the 4700 compares to a 4500 available at nearly 50% its cost. Still worth the extra?

 

[Francis Vaughan]

Doesn’t this prove with scientific measurement that capacitor can measurably affect SINAD by large amounts, assuming that Denon is honest about the capacitors (which I have no reason to suspect is untrue?)

Yup. But this is nothing new. There are capacitors and there are capacitors. Anyone who claims that all capacitors are benign and cannot affect the signal is simply ignorant. But that has never been the problem with audiofoolery. The problem is when there are claims that some magical super special capacitor is audibly better than a known good capacitor. High-k ceramic capacitors have been known to exhibit distorting behaviour pretty much since the dawn of audio. There are specific places in circuits where they should never be used. They are, and always have been a known bad capacitor in these roles. Perfectly good, indeed preferred in other roles. The EDN article I linked to above is just one of many references to the problem. Doug Self's works on audio design is another place you will find such things discussed. Heck I first heard about it back in the early 80's when I built by first amp.
A manufactuing problem with any capacitor might yield issues as well. Just getting the wrapping wrong in a foil or electrolytic could introduce microphonics. Modern manufacturing generally avoids these sorts of issues. But things happen, and any component might have issues.

 

[Bello]

With the updated 6700 measurements included, I updated my comparison table. As always, this is just for quick reference. For accurate numbers please refer to the ASR reviews.

View attachment 79326

Thank you!

My expectations have been met. Spec results were / and above my initial thoughts.

That said, I am still looking for a 3rd random re-test. We all need 100% confidence in Denon....................

As the saying goes "fool me once shame on you, fool me twice, shame on me." Please do whats right.

@amirm

Please plan into your schedule, an outsider for a re-test w/ spec'd production run s/n.

Maybe in the next 4 weeks, plenty of time for your cucumbers / pickles to cure. After, we'll also need taste test results as well as ingredients : )

Thank you!

 

[Vasr]

Inspection of the PCB would be very unlikely to be of use. The capacitors in question would be tiny surface mount, and display little to no useful markings.

PCBs in almost every manufacturer have version numbers to keep track of changes out of logitics and inventory necessity. A component change would most certainly have a version number change on the affected PCB.

Overall there is no reason to imagine the story is anything other than what Denon claim. An ingrained cynicism and desire to find fault and malicious intent seems to be part of modern society. Which is a great pity. It reflects more on those trying to find fault than anyone else.

???
Where does a healthy skepticism based on experience with industry norms and practices fit within that black and white world of yours?

 

[Kachda]

Not quite - this assumes Denon is being truthful, and if so, that a *bad* capacitor is at fault (not cheap). This is different to the audiophile 'fact' that better quality capacitors, even with the same capacitance are better. This is an electrical mystery to me, unless the 'low quality' capacitor is doing something the 'high quality' capacitor isn't.

@Francis Vaughan ’s post after mine explains this better

 

[Vasr]

Lastly- The infamous S/N from the your tested system. All I need is the last 3 digits... As I earlier mentioned, I had Denon level 2 support email me the (lot) last bad s/n and the start of the spec'd capacitor system S/N.

Please, please send us the (last 3 digit) tested s/n. If the system s/n falls inline with Denon's email. I will release the email to everyone.

There are interesting inferences you can make out of this.

If Denon support suggested only the last 3 digits were relevant (I don't know if that was the case or you are making this inference) , then it implies less than a 1000 were affected.

If they only gave the last S/N, then that would mean the entire initial batch up to that number were affected as they have said. Otherwise, you would need a starting and beginning number.

The fourth digit would also be relevant to see if this was the initial batch.

 

[Bello]

@Francis Vaughan ’s post after mine explains this better

I would think these components are tested in lab environment, components specifically designed for this specific audio circuit. With the best audio output results possible.

Off the shelf, equivalent capacitance will not perform as well (to spec) due too component make-up. Make sense?

To me, it's pure logic. What Denon did is totally out-of-line to keep production run moving. This must happen more then we'll ever know.

I'll need to by test equipment moving forward : (((