• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). There are daily reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Denon AVR-X6700H Home Theater AVR Review

OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
37,501
Likes
157,457
Location
Seattle Area
Thanks @amirm, there are few typos in legends in some of the plots (such as linearity, freq response, THD+N versus freq) where you brought in X4700H accidentally :)
Thanks. I think I fixed them all this time.
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
37,501
Likes
157,457
Location
Seattle Area
On a different note can you measure Lyngdorf MP40/MP60 please although it's expensive and out of reach.
It is difficult. I know the people in the company and could ask for a sample. But I hate to do that should it turn out that it doesn't perform.
 

GXAlan

Addicted to Fun and Learning
Forum Donor
Joined
Jan 15, 2020
Messages
741
Likes
1,024
@amirm
If true, this means that capacitors can affect sound quality. Did they identify which capacitor?
If true, this means that the anniversary X8500HA which will have "special 110th Anniversary" capacitors, might actually have measurable improvements.

Also kudos to Denon for transparency and willingness to admit issues. I'm sure there will be plenty of X6700H's that go unchanged (like any mail in rebate), but this is increasing my opinion of Denon as a company. They're not a charity -- but they certainly seem to stand behind their engineering, even for a mass-market product.
 

Vasr

Major Contributor
Joined
Jun 27, 2020
Messages
1,409
Likes
1,867
From what I understand, bad/faulty capacitors (poor matched sets, high variances, incorrect values, manufacturing defects, etc) can degrade sound quality. It is a harder case to make that better capacitors improve sound (except when upgrading from bad capacitors).

So, I wouldn't hold my breath for any perceptible magic to happen with any "anniversary capacitors". :)
 

Anterantz

Active Member
Joined
Jun 27, 2020
Messages
192
Likes
31
Denon's excuse for the bad result is incredible. As the owner of an 8500h I do not like these derangements at all, it makes the company more inferior and it seems that they are lurching!

Fear gives me when they measure the 8500h!

by the way are the sinad of the preamp always measured? never measured with internal amplification?

We have many that do not use external stages and we would like to see if this data is the same.

regards
 

studiocity

Member
Joined
Jul 18, 2020
Messages
29
Likes
24
It’s good that Amir made progress in working with Denon, but make no mistake if it were not for him and the ASR, Denon would not blink an eye at this, No body would even actually even know it. As they said, the Denon sound team fully passed the units even with the inferior capacitor. So it makes you wonder what else is going on. Remember I was one of the ones who had the 6700 on the first shipment, and it sounded ok, but I can’t say it sounded good, no matter how many adjustments I made, I tried them all and in every combination. So to me this is not a surprise, but hopefully the new cap makes the problems go away. It did cost me $1.5k in upgrade costs however to exchange with the 8500, that I really didn’t want to make. But the 8500 is doing great and when tested I feel confident it will have a good test. Amir didn’t test, but the 4K Video upconvert for the cable/dish set top box was much better on the 8500 than the 6700, and to me that is helpful when watching Indy car or formula one or football or baseball. So to me the 6700 is and was a no go. But it’s so great that Denon will exchange them. Amir your work is very valuable! Thank you!!
 

AudioJester

Senior Member
Forum Donor
Joined
Jan 7, 2020
Messages
488
Likes
575
Sigh. I must admit I am rapidly loosing faith in any audio manufacturer. They can get away with anything if Amir/ASR didnt keep them in check.
Makes me wonder how many other denon products are out their with owners not being aware of inferior components and not meeting spec?
Imagine what the response would be in the automotive sector.
 

Ucftechguru

Member
Forum Donor
Joined
May 19, 2020
Messages
59
Likes
47
Nice review @amirm. Another win for consumers! Those with faulty capacitors will have the ability to get this fixed thanks to you.

I'm very impressed with Denon's willingness to work with you and that they will be sending you a unit with the fixed capacitor.

Huge win for consumers and Denon. Any website that rates this receiver highly right now is bought and paid for by Denon and should not be trusted!!!!! Sad they would use a crappy capacitor. No one can get the x3600 anymore (probably because it rates so highly and they don’t want to cannibalize sales of higher end units like the x4700 and x6700) but they put a crappy capacitor in the x6700 to get it out the door and people bought it based off the great results of the x3600. Sad. Glad they “plan” to fix it. And as consumers SUPER KUDOS to Amir for finding this flaw.
 

restorer-john

Master Contributor
Joined
Mar 1, 2018
Messages
8,766
Likes
24,371
Location
Gold Coast, Queensland, Australia
If true, this means that capacitors can affect sound quality. Did they identify which capacitor?

The only capacitors that could conceivably affect the power output, noise performance and issues with driving multiple channels along with a propensity to prematurely shutdown would be the main PSU caps.

They are also the most expensive, the most likely to be substituted, or indeed, faked. Supply chain issues during Covid-19 could have resulted in sourcing capacitors from dubious suppliers...

In the interests of transparency, the two receivers should be compared side by side internally to quickly ascertain where the problem was/is.
 

F1308

Addicted to Fun and Learning
Joined
May 24, 2020
Messages
730
Likes
538
I had a budget of 25000 € or so to upgrade my system along 2020.
If Denon does so, I will believe in Jesus and just Jesus.
Blame Denon, but my spending has been cancelled.
Sticking to what I have.
Denon, Denon... billions of blue blistering barnacles !!!!
 

GXAlan

Addicted to Fun and Learning
Forum Donor
Joined
Jan 15, 2020
Messages
741
Likes
1,024
They are also the most expensive, the most likely to be substituted, or indeed, faked. Supply chain issues during Covid-19 could have resulted in sourcing capacitors from dubious suppliers...

In the interests of transparency, the two receivers should be compared side by side internally to quickly ascertain where the problem was/is.

At the turn of the century, this was a big problem in PC motherboards
https://spectrum.ieee.org/computing/hardware/leaking-capacitors-muck-up-motherboards

And this
https://www.theguardian.com/technology/blog/2010/jun/29/dell-problems-capacitors

The hard part is that Amir doesn't own this X6700H; it's on loan to him from a reader.
 

restorer-john

Master Contributor
Joined
Mar 1, 2018
Messages
8,766
Likes
24,371
Location
Gold Coast, Queensland, Australia
The hard part is that Amir doesn't own this X6700H; it's on loan to him from a reader.

Some high resolution internal photographs of the existing unit's main PCBs in and around the PSUs, the main power amp stages and any sub regulated supplies (front end VAS caps) and the regulated low level supplies would probably do it for comparison purposes.

My guess is they will take an existing production unit and repair it with the "correct" spec components and ship that for testing.

Denon aren't the first company to change components through a product lifecycle and certainly not the first to deliberately downgrade critical components after they realized they could get away with it. I've seen same model vintage power amplifiers go from 18,000uF, to 15,000uF to 12,000uF (main PSU caps) through the lifecycle to keep costs down. And yes, that did seriously affect the power output. (the first models tested way over spec)

Also note, I am not accusing Denon of such naughtiness. They are hopefully the victim here.
 
Last edited:

F1308

Addicted to Fun and Learning
Joined
May 24, 2020
Messages
730
Likes
538
My guess is they will take an existing production unit and repair it with the "correct" spec components and ship that for testing.

The one here in this shop is a bad unit or a good one...?
Mmmmmm...... Billions of blue blistering barnacles.
 

RickSanchez

Major Contributor
Cartographer
Joined
Sep 4, 2019
Messages
1,162
Likes
2,401
Location
Austin, TX
Thanks for measuring the ECO mode performance, Amir. I know from experience with my Denon AVR that ECO mode = auto definitely keeps the unit running fairly cool but was curious if/how it affected amp performance. (I'm assuming that ECO mode is implemented the same for all recent Denon AVRs, although that might not be the case.)
 

Xyrium

Addicted to Fun and Learning
Forum Donor
Joined
Aug 3, 2018
Messages
532
Likes
448
Captain, you certainly have been busy this week!!! I'm loving that this forum is driving manufacturers to respond to the issues. I'm also truly appreciating the level of effort that Denon has put into those responses Good stuff all around...
 

F1308

Addicted to Fun and Learning
Joined
May 24, 2020
Messages
730
Likes
538
also truly appreciating the level of effort that Denon has put into those responses

Seriously...?
You hear a sound while driving your Audi A8 W12 and you open the bonnet to discover an engine belonging to a 50cc motorcycle and you are happy enough after their telling you Covid is to blame...?
 

zelig

Active Member
Forum Donor
Joined
Jun 16, 2020
Messages
129
Likes
144
I would be very surprised if after the x4700h fiasco Denon hasn't already tested all their latest models and know what's coming down the pipe at them. That's what I would do anyway. They will likely have already prepped excuses and potential mitigations, including stories of dodgy capacitors.

What is super important is that Amir doesn't source the equipment to test from manufacturers but uses essentially random units from consumers. This makes it real hard for manufacturers to skew reviews by providing "tuned" samples that might not represent anything consumers will ever get their hands on. Anyone with the knowledge and the right equipment should be able to replicate Amir's tests, and I seriously hope that the Denon folks can do so otherwise they shouldn't be in the AVR business. Let them fix the units already released to the wild and test one of those at random.
 
Last edited:

F1308

Addicted to Fun and Learning
Joined
May 24, 2020
Messages
730
Likes
538
I would be very surprised if after the x4700h fiasco Denon hasn't already tested all their latest models and know what's coming down the pipe at them. They will likely have already prepped excuses and potential mitigations, including stories of dodgy capacitors. What is super important is that Amir doesn't source the equipment to test from manufacturers but uses essentially random units from consumers. This makes it real hard for manufacturers to skew reviews by providing "tuned" samples that might not represent anything consumers will ever get their hands on.

The mistake they have made can only be called PANDORA'S BOX.
25000€ have already been deprived from the market....and that is just only me.
DMMTS.
 

Vasr

Major Contributor
Joined
Jun 27, 2020
Messages
1,409
Likes
1,867
Seriously...?
You hear a sound while driving your Audi A8 W12 and you open the bonnet to discover an engine belonging to a 50cc motorcycle and you are happy enough after their telling you Covid is to blame...?

That is a bit extreme analogy.

This is more like you think you feel a bit more vibration in your engine and you have it checked out and the mechanic says, they have used Autolite spark plugs rather than the original NGK ones and the car manufacturer blames the supply chain shortage for the switch but that they feel the replacement was acceptable and offer to replace it IF you ask for it.

These supply chain disruptions happen all the time even without the pandemic. Benchmark amps were delayed because of the heat sink supply disruption but they delayed it rather than put something else that wasn't as efficient at cooling.

Here the Denon rushed it to market with a replacement component. They claim their Sound Master (!) deemed it acceptable. Have no idea if this was a ear test or a measurement test or just market BS.

However, I would neither skewer Denon nor put them on a pedestal just because of their response. So far it has been reactive to potential bad PR. How they take care of it after this has come out will determine their corporate culture.

If they are still shipping the same units and just lied about it being a short production run (and companies do this not infrequently), then that would be different from if they did have a batch problem, identified the serial numbers and soon we will see a public announcement from them on their web site stating which serial numbers are affected and asking owners to get in touch.

I hope the owner of this unit will allow or open it to take some pictures as @restorer-john suggested to compare later and with units that they deem is after that problem production run. Part of holding them accountable - Trust but Verify. :)

I firmly believe testing a unit that they will ship out is not fair for any other AVR in the comparison chart. They could test it to ensure the best measurements as done here even if it varies from the production runs. We would never know.
 
Last edited:

Xyrium

Addicted to Fun and Learning
Forum Donor
Joined
Aug 3, 2018
Messages
532
Likes
448
Seriously...?
You hear a sound while driving your Audi A8 W12 and you open the bonnet to discover an engine belonging to a 50cc motorcycle and you are happy enough after their telling you Covid is to blame...?

They blamed no one but themselves. Whether it's a capacitor, or a complete design flaw, they've been in communication, and have even remeasured gear to validate any findings. So, sure, I'd rather the manufacturer admit fault, rather than blame someone else, or claim the problem doesn't exist.

Though I must say, what's up with all of the Denon AVR's coming through here lately? Weird...
 
Top Bottom