Denon AVR-X6700H Home Theater AVR Review

[Bello]

I agree 100%, only after the test completion of the 6700H. Take some time off, a trip to Hawaii, Fuji islands... Japan?

Maybe interview with Denon? They could probably use your skill set

You certainly deserve some R&R.

Stay safe!

 

[peng]

Maybe interview with Denon? They could probably use your skill set

That will be great, I can't wait for that to happen. Make it "live" too and take questions.

 

[Keenan]

Unfortunately not. I don't have a reservation system to keep track of such things.

I'll contact you in a month or so then when you've recovered from the Denonitis.

 

[Urgo]

As I said on another occasion, I had to return my Denon x6700h the first day because it went into protection mode as soon as it was connected.
On the same day of the return, ASR tests were published that found the capacitor problem, which probably has nothing to do with the malfunction of my unit, but after the poor measurement results, I decided to get my money back.

Denon's performance in this matter may have been good according to some opinions, but for me it is not entirely satisfactory. Without confirming that all the units involved have been recalled, or publishing the serial numbers, I dare not buy this model again, and my fear extends to its Marantz 8015 counterpart.

I'm also not too reassuring that Denon is now sending a new tuned unit to repeat measurements. Although it works perfectly, mistrust will continue to exist if they do not identify and confirm that they have retired the old units, the new purchase will always be a lottery.

Sorry for the google translation

 

[Bello]

From my earlier post's. I'd like to hear from at least one person with a non-affected 6700H, off-the capacitor hit list.

Anybody?

During my correspondence with Denon, it seems they discounted the issue to a minimum production run. But, I've yet to hear from anyone with a good unit. Or maybe the few of us on this forum (including myself) have the worse luck ever. Highly doubtful...

 

[Caligari]

@amirm Any chance this capacitor was used in any X4700H ones?

 

[somy]

Looks like not a good option for music. It would be nice to have one machine rules both AV and HIFI...

 

[DrewMcG]

@amirm Any chance this capacitor was used in any X4700H ones?

Seems unlikely based on Amir's updated X4700H review results, and the fact that it was made in a different country than the X6700H.

 

[amirm]

Updated review with capacitor fix: https://www.audiosciencereview.com/...ds/denon-avr-x6700h-avr-review-updated.15484/

 

[amirm]

@amirm Any chance this capacitor was used in any X4700H ones?

No.

 

[Fillius]

An update on my X6700.

Sound United Support have come back to me, they will be getting the replacement boards in early next week to swap the PCB in mine.

I'm disappointed that I don't get a full replacement unit (just because I'm in the UK, not US). But if I end up with a one that measures well and still has its full warranty (3 years from my retailer) then that's what really matters.

It's great to see the updated unit has measured much better pretty much across the board.

Thanks again @amirm for all your hard work, it has made a real difference!

One benefit to this, despite the effort involved, is that while my X6700 is away, I will be going back to my Onkyo so I will be able to compare it after my time with the Denon. I have been hearing distortion on voices and SFX around 600-800Hz. My partner can't hear it so I'm suspecting it is my ears (or hers , although I have had occasional hearing problems in the past). If I don't hear it with the Onkyo on the same source content then I will know it was the Denon, if it's still a problem with the replacement caps then I'll have to return the unit as faulty.

 

[peng]

An update on my X6700.

Sound United Support have come back to me, they will be getting the replacement boards in early next week to swap the PCB in mine.

I'm disappointed that I don't get a full replacement unit (just because I'm in the UK, not US). But if I end up with a one that measures well and still has its full warranty (3 years from my retailer) then that's what really matters.

It's great to see the updated unit has measured much better pretty much across the board.

Thanks again @amirm for all your hard work, it has made a real difference!

One benefit to this, despite the effort involved, is that while my X6700 is away, I will be going back to my Onkyo so I will be able to compare it after my time with the Denon. I have been hearing distortion on voices and SFX around 600-800Hz. My partner can't hear it so I'm suspecting it is my ears (or hers , although I have had occasional hearing problems in the past). If I don't hear it with the Onkyo on the same source content then I will know it was the Denon, if it's still a problem with the replacement caps then I'll have to return the unit as faulty.

You should include the issue about the audible distortion in your complain ticket and attach a note on the same in the box for return.

 

[Fillius]

You should include the issue about the audible distortion in your complain ticket and attach a note on the same in the box for return.

Thanks for the suggestion. Before I send it I'll plug the Onkyo back in, if there's no distortion I'll know it's not my ears. Until then I can't be certain and don't want to make an unfair complaint.

 

[studiocity]

Hi amir in this review you mentioned that grounding between the test instrument and the x6700h was causing different results on the two amplifier audio Channels Then you corrected this and the readings improved for the other channel. Could this also be the case when you tested the x8500h, as you indicated In that test, that the two channels were not measuring the same on the x8500h. Could the x8500h test results have been improved if you had implemented this change in grounding as well? I remember you were disappointed that the x8500h amplifier measurements were not the same or closer for the two channels under test. You had said that if they were the same that this would elevate the score/ranking score considerably.

 

[peng]

Hi amir in this review you mentioned that grounding between the test instrument and the x6700h was causing different results on the two amplifier audio Channels Then you corrected this and the readings improved for the other channel. Could this also be the case when you tested the x8500h, as you indicated In that test, that the two channels were not measuring the same on the x8500h. Could the x8500h test results have been improved if you had implemented this change in grounding as well? I remember you were disappointed that the x8500h amplifier measurements were not the same or closer for the two channels under test. You had said that if they were the same that this would elevate the score/ranking score considerably.

I was very curious about how Ch1 and 2 can differ by that much for the much better build AVR-X8500H. Even the AVR-X3500 at 1/4 the cost did not have the same issue.

@ 5 W output CD input:

X8500H.................................. Ch1 81.712 dB, Ch2 86.152 dB
X3500H.................................. Ch1 82.898 dB, Ch2 81.283 dB

Note that Amir said "The amplifier did not change but improved grounding did make some things better. In Dashboard we are dominated by distortion so this remains the same "

 

[Daniel0]

I was very curious about how Ch1 and 2 can differ by that much for the much better build AVR-X8500H. Even the AVR-X3500 at 1/4 the cost did not have the same issue.

My guess is the longer cabling is the issue with the 8500. The single channel amplifier boards are left and right in a bigger chassis while on the 4000 series and below the power amplifiers are more closer together (on 1 or 2 boards) and the cabling is much tidier and shorter.
I wouldn’t think the single channel amplifier boards have worse performance than the amps on the lower end models.

 

[Archaea]

I haven't called about my X6700H unit yet, but I will.
I wanted to give it some time to fall out and just see how this unfolded. All seems pretty quiet at this point.

I bought my unit on July 6, and as far as I can guess, I probably have the 370th unit off the line from May 2020 with this serial number: DBCY052000370

It does annoy me that I bought the X6700H and it measure worse than the other units in this family lineup. Even if its actually inaudible, it sits uncomfortably on my mind.

The other dubious concern is how would we, the consumer, even know if it was properly repaired. It could be whisked away by FedEx for the capacitor replacement, and sent back to us with the same, or a different issues. It's not a comfortable position to be in as a Denon customer. One would like to think these types of variations would not exist on higher end gear. This is my third Denon unit in 10 years, and I was pretty hot on the brand until this. Not so sure now.

Denon 4520CI
Denon X7200WA
Denon X6700H

 

[Bello]

I haven't called about my X6700H unit yet, but I will.
I wanted to give it some time to fall out and just see how this unfolded. All seems pretty quiet at this point.

I bought my unit on July 6, and as far as I can guess, I probably have the 370th unit off the line from May 2020 with this serial number: DBCY052000370

It does annoy me that I bought the X6700H and it measure worse than the other units in this family lineup. Even if its actually inaudible, it sits uncomfortably on my mind.

The other dubious concern is how would we, the consumer, even know if it was properly repaired. It could be whisked away by FedEx for the capacitor replacement, and sent back to us with the same, or a different issues. It's not a comfortable position to be in as a Denon customer. One would like to think these types of variations would not exist on higher end gear. This is my third Denon unit in 10 years, and I was pretty hot on the brand until this. Not so sure now.

Denon 4520CI
Denon X7200WA
Denon X6700H

When I realized I had the choice in getting my 6700H replaced (not fixed) I was put at ease. I also did not take the route of having Denon swap the system and lose my 60 day return guarantee. I'll be sticking with my vendor w/ a new replacement (s/n check) prior to shipment.. With a second round of a 60 day money back and or new swap. If I run into a problem during testing.

Crutchfield has been outstanding in that regard and beyond. Extremely professional, completely hassle free, 60 day returns.

I highly recommend Crutchfield.

 

[Anterantz]

Hello guys, a question in cinema, do you activate or deactivate the midrange compensation? Central and frontal? Regards

 

[tvstaff]

This is a review and detailed measurements of the Denon AVR-X6700H "8k" 11.2 channel Audio/Video Receiver. It is kindly loaned to me by a local member and costs US $2,499 on Amazon with free shipping.

AVRs look the same these days and the AVR-X6700H is no exception:

View attachment 74970

Inside though, is quite full as indicate by large number of amplifications with speaker terminals in the back:

View attachment 74971

I did not invoke the ECO mode. Without it, the unit runs quite warm. Some instrumentation on this later.

I tested the 6700H a couple of weeks ago and found what I considered performance issues. I ran the subset of those measurements by Denon. They examined them and confirmed that the measurements are correct for the unit I have and is due to capacitor substitution. They provided me with this statement to share with you:

“Denon is pleased to work with ASR once again, who kindly shared his Denon AVR-X6700H measurement results with Denon engineering. The initial results ASR shared were surprising and prompted an investigation, which resulted in Denon engineering identifying measurement irregularities caused by a particular capacitor used in the initial production run to mitigate a supply issue caused by the COVID-19 pandemic. The latest production units have the capacitor Denon typically uses, which does not show the same measurement results.

Even with the previous production units affected by the capacitor constraint, Denon sound masters approved the audio quality in the initial AVR-X6700H production run and we’re confident it sounds just as good as the latest production units. However, if you purchased a Denon AVR-X6700H and have concerns, please reach out to Denon customer support after August 5, 2020 and we will verify if your unit is affected and offer a replacement if merited. “

They will be sending me a newer unit without this issue for testing in the future. I will be updating this review when I get that sample and test it.

AVR DAC Audio Measurements
As usual we start by feeding the AVR over HDMI a 1 kHz tone and see how much noise, distortion and unwanted signals are present in the pre-amp output. I set the volume to 82.5 which produces the nominal 2 volt we see from stereo DACs (see later for performance at other levels):

View attachment 74974

Note that the amplifier for the two channels being tested is turned off to avoid its clipping behavior impacting the DAC portion. We see a distortion spike rising up to -88 dB which is high enough to dictate SINAD which is a sum of noise and distortion to the same level. This is quite a regression relative to AVR-X4700H to the tune of 8 dB.

I tested using Coax and got the same performance so this is not HDMI channel mixing issue we have dealt with before.

While troubleshooting this behavior, I noticed that the level of distortion varies with time. See this second measurement for example:

View attachment 74975

So I powered the unit down, let it cool some and then measured SINAD over time:

View attachment 74976

The instant the test is started, SINAD is nearly 90 dB but drops after a minute or so to 86 dB.

As noted, Denon engineering traced this to a faulty capacitor in early units (I provided the serial number for this sample and they confirmed that it does use this faulty cap).

Running with what we have, this is the ranking then:

View attachment 74977

We are now in the "red" category of DACs which I don't consider to be good. The AVR-X3600 from last year now enjoys a commanding lead, bettering the AVR-X6700H by a whopping 12 dB. Hopefully the manufacturing fix narrows and closes this gap.

Lowering the output level does not change the equation much:
View attachment 75006

Here is our signal to noise ratio:
View attachment 74978

Intermodulation test vs level shows a saturation problem as early as -20 dB:
View attachment 74980

32-tone test resembling "music" shows dramatic increase in intermodulation distortion as frequencies rise: (label should say 6700)

View attachment 75038

This manifests itself in THD+N versus frequency just as well: (label should say 6700H)

View attachment 75036

Unimpressive out of band filtering in the DAC contributes to above: (label should say 6700H):
View attachment 74983

On less depressing note, Jitter performance is good:

View attachment 74984

Linearity suffers from secondary power supply tone close to test frequency of 200 Hz:

View attachment 75035

AVR Analog Input Amplifier Measurements
The CD input on Denon AVRs is not digitized which makes for a good input to test the amplifier's raw performance outside of digital processing:

View attachment 74986

This is above average performance for all amplifiers tested regardless of type:
View attachment 74988

Within AVRs, it lands in the crowded middle:

View attachment 74989

Frequency response is flat and bandwidth quite wide:

View attachment 74990

Crosstalk is reasonable:
View attachment 74991

Signal to noise ratio could be better at 5 watts (like to see 16 bits of dynamic range there):

View attachment 75059

The most important measurement here is power output so let's get into that using 4 ohm load driving 2 channels simultaneously:

View attachment 74993

Lots of power at 180 watts. One channel has worse distortion though.

Allowing for more distortion at 1% we get this much max and short-term power outputs:

View attachment 74994

That's 600 watts of short-term power which is nice! You get a benefit from a power supply that is designed to drive a lot more channels than two in this test.

Switching to 8 ohm we get:

View attachment 74995

Rated spec is at higher distortion than I allow so we are good here.

Edit: forgot to include this measurement in the original review:

View attachment 75008
Overall for the class, this is very good power and general performance.

Eco Mode Amplifier Performance
I measured the effect of leaving Eco mode in auto versus On (above tests were with ECO=OFF):

View attachment 74996

As with my previous tests, auto mode has no impact on performance. The switching seems well, seamless.

Turning on the ECO mode not only limits power to just 38 watts but also raises the noise level some. So auto mode would be the preferred mode of operation if you need the power saving and heat reduction.

HDMI Input Amplifier Performance
Since majority use HDMI as the chose input, I ran a separate test on its performance:

View attachment 74997

There is essentially no impact because the DAC performance was a few dBs better.

Multichannel Amplifier Power Response
I ran a test where I increased the number of channels driven from 1 to 5 channels using 8 ohm impedance (did not want to press my luck with 4 ohm load):

View attachment 74998

Above is using 1% THD+N. You still have over 100 watts of output with all five channels running.

The testing as is standard in the industry is at 1 kHz. I thought I run a sweep from 20 Hz to 20 kHz and step through the channels just the same. Alas, after adding the third channel, the AVR went into protection mode immediately and shut down. This tells me the actual available power in bass where most of the action is, is lower than the above bar chart indicates. When I get the second sample from Denon, I will run this test again and verify this issue.

EDIT: Forgot to include these in the original review.
Thermal Performance
As I have been commenting, these Denon/Marantz AVRs run pretty warm. So I thought I take a snapshot after my testing using my IR camera:
View attachment 75451

As we see the hottest area is the row of heatsinks. Zooming in we get the peak temperature:

View attachment 75448

As we see the peak temperature is 72 degree C (161 F) and this is the heatsink. The junction temperature for the power output transistors will be much higher. And this is with the AVR in "open air" and not in any kind of cabinet. So be careful about amount of airflow.

Conclusions
Stepping up in Denon AVR line gets you progressively more power and that is indicated in my measurements. Amplifier running out of power is a key aspect of sound quality suffering so this is good.

Alas, the performance of the pre-amp output is disappointing in the way it has regressed relative to other units in the line. Hopefully the later production units perform better. Until I can verify that, I can't recommend the Denon AVR-X6700H.

-----------
As always, questions, comments, recommendations, etc. are welcome.

The number of messages I get in my forum inbox has exploded as of late. I need to hire someone to impersonate me and answer them. I can't find anyone as good looking as myself but since people can't see my image in these messages, maybe I have some hope of finding someone to do that. They won't work for free though so please donate what you can using : https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

I can't thank you enough.

I was about to buy a 6700 and 4700 to drive 6 Zones in a new house you saved me. I own a 4308CI and I'm shocked at the poor quality, noise and heat of the 6700 and 4700.

I'm old and have 6 zones to drive and I'm lost. Can't afford custom install. You saved me from making a very expensive mistake. Thank you