Denon AVR-X6700H Home Theater AVR Review

[studiocity]

I am looking forward to the Amir testing on the x8500h, to see how the slightly different design will show up in testing. It sounds great so far, one week in. Does anyone else have the 8500? How does it sound from listening test, what is your experience?

 

[Roivas]

@amirm
Hello. I'm new here. Your review of the denon X6700H has been posted on a forum I follow in my country.
I learned about the CAP problem while reading it. I'm a noob & english is not my 1st language, so I didn't really understand everything about the caps problem.
I ordered the X6700H & should receive it in a week. Could you explain to a novice in simple words what this cap probem does exaclty to the sound? If my receiver have a faulty cap, will I be able to know it without any measure instruments?
Buying the 6700H is a big investement for me, I only buy AVR like 1 every 10/15 years & I want to make sure it will last & it will sound at it was intended :x. Thx for your test & your help. And excuse my english *.*

 

[amirm]

I ordered the X6700H & should receive it in a week. Could you explain to a novice in simple words what this cap probem does exaclty to the sound? If my receiver have a faulty cap, will I be able to know it without any measure instruments?

You won't be able to hear it. The distortion is still low enough to not be noticed in normal listening.

Still, if the company will fix it for free, I would ask them to do so.

 

[Roivas]

You won't be able to hear it. The distortion is still low enough to not be noticed in normal listening.

Still, if the company will fix it for free, I would ask them to do so.

Thx for your answer. That was fast lol.
Ho sure I would ask them to fix it, but how I'll know I've a faulty version or not if I can't hear it.

You think they'll give a list of serial number affected by the problm? There's no "news" page on the official denon site in my country ... If they publish the serial number, I'll have to hope US serial & EU serial works the same ^^;

 

[amirm]

Thx for your answer. That was fast lol.
Ho sure I would ask them to fix it, but how I'll know I've a faulty version or not if I can't hear it.

You think they'll give a list of serial number affected by the problm? There's no "news" page on the official denon site in my country ... If they publish the serial number, I'll have to hope US serial & EU serial works the same ^^;

They say to contact them. WHen you get yours, just send them a message with serial number and they can tell you if it has the problem. That is how they checked the one I reviewed.

 

[jalaute]

It has a deadline to return so probably in the next two weeks.

Please consider evaluating temperature during “all channels driven” testing (as practical): Possible scenarios to consider: (3X00-6X00 series)- all internal, L/R out + internal, and L/R/C out + internal, and for the 8500- all internal, L/R/C out + internal (full and Eco). Ideally, temperature testing could be incorporated in parallel with your existing testing flow/protocol, and may be relevant to other “hot” receivers.

Heat is the bane of electronic performance and reliability. Watching your Denon testing progress (from 9 ch. at 105/120W ea., to 11 at 140, and (upcoming) 13 at 150), with their “hot” characterizations, only increases my desire to find ways to mitigate it, as I consider purchasing options.
My intent in the 4700 thread, revolved around the idea that adding an external amplifier would/could/should confer benefit, and was an attempt to begin to try to quantify some of that potential benefit.

I believe my rationale is generally applicable to all receivers: heat, dynamic headroom, (potential) distortion, (potential) EMI, and power supply capacity/conservation (for the remaining channels/system) are all areas I would expect to see some level of benefit (both internally and externally) from using an additional 5 channel (3X00/4X00) or 3 channel (6X00/8500) amp.

The 8500 is the only Denon model to allow selective pre-out configuration beyond L/R (without applying the “nuclear” pre-out “all” option). What is not clear is the impact L/C/R “offloading” would have on its system level heat product. After all, it’s a big, tightly packed unit with a lot going on- AKA a modern rxr.

Eco mode (heat reduction) appears to only be a global option. With L/R/C out, it may be possible that Eco mode (8500 Eco level TBD) could be sufficient to drive surround channels. On second thought, is Eco mode even an actual viable operating mode for home theater? Internal and external amps are still driven by the pre-amp- as vol is increased beyond some level, won't the unit globally revert back to full power mode...

BTW, regarding BsdKurt “It feels like the Star Trek episode…” (p.5)- Thank you for ASR. It is an incredible resource.

 

[Vasr]

I'm not following the relevance of several of the comments above (economies of scale; diminishing returns; structure of avr industry, etc.).

Since you seem to be referring to my post, it was a response to the comments earlier on why can’t AVR manufacturers build AVRs with as good a performance as stereo amp and preferably at or less than the price of a stereo amp (and throw the rest of the AVR in for free) and if they are not doing that, is it because they are deliberately exploiting the customers?

 

[amirm]

Please consider evaluating temperature during “all channels driven” testing (as practical): Possible scenarios to consider: (3X00-6X00 series)- all internal, L/R out + internal, and L/R/C out + internal, and for the 8500- all internal, L/R/C out + internal (full and Eco). Ideally, temperature testing could be incorporated in parallel with your existing testing flow/protocol, and may be relevant to other “hot” receivers.

Proper thermal analysis requires probing inside which I cannot do with loaner gear. I can continue taking infrared measurements though as I did here.

 

[valerianf]

if they are not doing that, is it because they are deliberately exploiting the customers?

It is a problem of making money with less audio quality provided.
It is a problem of business model: they do not try to improve the sound technical performance as the Japanese did in the 80's.
Side effect: each decade, the number of AVR manufacturers is shrinking.
Let us keep some hope for the 3700h.

 

[Vasr]

It is a problem of making money with less audio quality provided.
It is a problem of business model: they do not try to improve the sound technical performance as the Japanese did in the 80's.
Side effect: each decade, the number of AVR manufacturers is shrinking.
Let us keep some hope for the 3700h.

I agree with prognosis but not the diagnosis.

 

[peng]

but the sinad tests of the 4700/6700 that midio amir were not measured in the pre-2v output? So I asked if you could measure the sinad in 2ch with the internal boards of the 8500h itself to see if sinad is bad too

Okay I thought you meant measurements of the power amp output, so it is about pre-out, thank you for the clarification, but what is midio?

Anyway, take a look again of the graph below and it may answer your question whatever it is.
The dark blue and red lines were measured SINAD with the internal amps disconnected.
The dark and light green lines were measured SINAD with the internal amps connected.

Since Amir has indicated this graph will now be standard for AVRs/AVPs, so you should be able to see one for the 8500 in a couple of weeks, I guess.

The 8500 has a better DAC IC but it has the same volume control IC that appears to be the bottom neck for pre-out SINAD so my bet is on it measured similarly well/or bad as the X3600H and X4700H. I doubt it would have suffered from the substituted cap like the 6700 had because there were no C-19 or anything else at the time that caused shortages. It may do a little better in noise as it evidently has better power supplies, general layout but then the even better layout/shielding scheme of the Marantz AV8805 that is blood related, did not do as good as the little AVR-X3600H or the X4700H, so I would be prepared to get surprised and disappointed, have to wait and see..

 

[peng]

The issue is in the DAC/Pre-amp so yes, it will impact external amplifiers just as well.

This is a serious issue, and I bet the person who signed off on the substitution (albeit evidently temporary)believed users would not be able to hear the difference between the batch with the substitute cap and the batch that has the originally specified cap in the BOM. That is, the difference between 87 and 97 dB SINAD at 2 V, and about the same 10 dB difference in the other tests, a little less in imd,, about 5-8 dB difference from what I could see. The power amp output SINAD also suffered a little less apparently. While that decision maker might have been right if he did believe that, but if I were in the position of hiring and firing, he/she would likely be fired, well, depending on the results of a thorough investigation obviously just to be fair.

 

[Gedeon]

The best way to solve this issue is to release a firmware update which will check the serial number and, if it’s included in the faulty list, will automatically show the user a form.

That form will only ask for an email address. Then, Denon will send to that address a customized link in which the owner will complete all the needed info to queue the replacement order.

With this system Denon will be able to reach all 6700 owners of a substandard unit.

 

[zelig]

The best way to solve this issue is to release a firmware update which will check the serial number and, if it’s included in the faulty list, will automatically show the user a form.

That form will only ask for an email address. Then, Denon will send to that address a customized link in which the owner will complete all the needed info to queue the replacement order.

With this system Denon will be able to reach all 6700 owners of a substandard unit.

The chances of that happening are zero. Besides obvious technical risks of providing an input form on an AVR (OMG!), Denon are in the business of keeping their customers happy. That includes not disturbing happy customers who are oblivious to the issue. Now if there was a chance units could go on fire and burn their houses to the ground, then yes, your approach might be a good idea.

 

[GXAlan]

While that decision maker might have been right if he did believe that, but if I were in the position of hiring and firing, he/she would likely be fired, well, depending on the results of a thorough investigation obviously just to be fair.

Fired or promoted?

 

[peng]

Fired or promoted?

Fair point, it may depend on if I were the head of the marketing, finance or engineering department..

 

[rccarguy]

Just a pity marantz/Denon get baking hot...someone said can't even touch the top of the marantz avr.


Maybe designed to fail?

 

[robross0606]

So how can one know if they have a unit with inferior faulty caps? I am an owner of the 6700. I haven't noticed many problems with the audio, but I have noticed some pretty poor issues with HDMI:

• Chroma 4:4:4 doesn't look right
• Spotty HDMI hotplug and HDCP handshakes

I'm wondering if I should return it and wait for a future production run. Or perhaps pass on it altogether and stick with my old Onkyo TX-NR3007.

 

[Chriz]

To get the gain to be 29 dB, you have to use the volume of 82.5 which is what I do for DACs and people complain that this is beyond reference.

Hi Amir,

love the work you are doing here, so many thanks.

I have one question, that I had asked in another review, but wasn’t has answered (I believe), so I dare to ask it gain.

Currently, I am using a Denon 6500, and are about to switch to the 6700 for the amp disconnect feature, as I am (since recently) using a dedicated 2CH amp for the mains.

Now, it was said that the Denons have a gain of 29dB. My external amp has a gain (according to the spec) of 30,5 +-0,5dB. I am using a separate preamp/amp for 2channel listening, and connect the Denon via a home theatre input pass thru when watching movies (lucky me the manual says that it has sensitivity of 1.3V, so I guess it reaches max. power at that voltage, which is below the range where things get worse with amps connected (which I cannot disconnect anyway with the 6500).

So my question is: What exactly does it mean that the AVR has a lower gain than my external amp. From the spec, I have a deviation of between 1 (30,5-0,5) and 2 dB (30,5+0,5).

My best guess is that at reference level (measured and set through Audyssey) all is fine, but when I turn down the volume, the relative volume changes between the speakers connected to the external and internal amps respectively. How I understand gain would mean that my L/R, since the external amp has a higher gain, would play (significantly?) lower in relation to speakers connected to the internal amps.

How significant is this really becoming at let’s say -5db and -10db reference level.
(I have the luxury to actually being able to view a movie in this range, revLevel to -10dB...)

Many thanks,
Christoph

 

[North_Sky]

Denon execs must be wetting their bedsheets ...