Denon AVR-X3700H AVR Review

[bigguyca]

My memory doesn't go back that far. But fortunately the site does. From my review:

View attachment 76705

FYI I am in discussions with Denon/Marantz folks about thermal issues. They like to investigate what I have reported. I am asking them to lower the threshold for the fans to come on. Will see if they go for it.

Blowing dust in to the units, when the fans might not actually be required, is a good way to create thermal problems when none previously existed. Increasing the duty cycle of the fans adds a potential area for mechanical failure. Fans also add noise, which is undesirable. Dust covered fans add more noise. The use of fans to effectively cool electronics really should include filters for the air entering the unit and other engineering steps. It requires a systems approach.

The thermal and current protection systems in the Denon's, especially the higher level models, are quite extensive and clearly have been the subject of extensive engineering by Denon. If the thermal systems are poorly designed in isn't for a lack of trying or attention to the subject on Denon's part. The three year warranty period is long enough that Denon needs to get the thermal system "right" or warranty claims will be excessive.

There is a tendency to personify the temperatures found in electronics. AVR's aren't people! Don't be irrational about this.

 

[RichB]

Blowing dust in to the units, when the fans might not actually be required, is a good way to create thermal problems when none previously existed. Increasing the duty cycle of the fans adds a potential area for mechanical failure. Fans also add noise, which is undesirable. Dust covered fans add more noise. The use of fans to effectively cool electronics really should include filters for the air entering the unit and other engineering steps. It requires a systems approach.

The thermal and current protection systems in the Denon's, especially the higher level models, are quite extensive and clearly have been the subject of extensive engineering by Denon. If the thermal systems are poorly designed in isn't for a lack of trying or attention to the subject on Denon's part. The three year warranty period is long enough that Denon needs to get the thermal system "right" or warranty claims will be excessive.

There is a tendency to personify the temperatures found in electronics. AVR's aren't people! Don't be irrational about this.

After cleaning the Coolerguys fans (that blow out), the output is much greater and the 3700H is significantly cooler in the cabinet. I am staying with this approach because the never removed or cleaner Onkyo had some dust on the back but no in the center front.

The fan-dust could not be blown off. I had to disassemble and carefully rinse the fan to avoid dousing the electronics. I'd rather clean the cabinet fans than crack open the AVR.

- Rich

 

[Daniel0]

The three year warranty period is long enough that Denon needs to get the thermal system "right" or warranty claims will be excessive.

The higher end Denon/Marantz models have a 5 year warranty in Germany since 2019.

I don't get the concerns about long term reliability either. They run below 70 degrees Celsius which is the Temperature the fans start spinning at.
My 10 year old Onkyo Receiver was way hotter than my current Denon, and the amps overheating was certainly not the issue of these devices around that time. It was the faulty HDMI boards which had problems for years, mine didn't have an OSD or scaling because of that too.

I agree that there should be an improvement but i'm not overly worried about it.
And i completely agree with you that the fans shouldn't work at lower temperatures since that gets you another set of problems you mentioned.

It should be enough if they icrease the size of the heatsinks a little bit. They are certainly not very expensive, and as the market leader in the AVR market Sound United should strive for the best and not average performance.

 

[reg19]

OK, here it is:

View attachment 76454

Notice that I have to turn the volume up to 89 or you won't get 4 volt output. Once there, the AVR switches gain stages causing performance to drop across the board. In addition, as the graph says, you can't go to 4 volts. Max usable is 3.73 volts.

Thanks Amir.

As a novice, I'm still confused as to what this exactly means.

So, say, I have 3700H pre-outs to a power-amp for front 2 L-R channels and use the AVR amplification for the center and 2 surrounds.
In that situation, shall the L-R pre-outs also clip at 1.2V (green line in your graph)? Or would that only be applicable to the center and 2 surrounds (ie: for feeding internal amplifier)?

I understand the orange and green lines in your graph. What is that 3rd line ('Denon AVR-X3700H')?

 

[Obiden]

How is the video section comparing to 3600

 

[theglobalelite]

How is the video section comparing to 3600

These 2020 models support HDMI 2.1 which means 8K video, 4K @ 120hz, and many other new features: https://icdn7.digitaltrends.com/image/digitaltrends/featuresupport-100743741-orig-1120x651.jpg

 

[amirm]

Is it possible Denon has the thermal threshold set to higher temps (no fan spin) so not to introduce electrical noise? / added audio distortion from spinning fans? and or dust contamination to components. As I earlier mentioned, Denon responded back as to my heat concern. Response regarding the fans only spin up when the AMPS reach a critical state 160 - 210 degrees. I believe Denon's extensive thermal testing during design / build, Denon accepted to hover around 150 - 160 degrees (hot, no fan spin) temps fully operational during semi heavy use. I believe these measurements are well thought out during design test bench burn-in. Likely, tests are open air operating temps. Not closed-up in a cabinet. If you notice, all of there system marketing displays are always sitting on top (open air) of consoles never inside...

I don't know any of that. What I am asking them is if the fans are turned on under processor control, an option be given to the buyer to set the threshold lower. If it is hardware controlled then nothing can be done with this generation.

 

[amirm]

The thermal and current protection systems in the Denon's, especially the higher level models, are quite extensive and clearly have been the subject of extensive engineering by Denon.

You could say the same thing about Sony but I blew up my brand new one with a stress power test. It got so hot I could smell the burned enamel of the transformer winding.

 

[Bello]

I don't know any of that. What I am asking them is if the fans are turned on under processor control, an option be given to the buyer to set the threshold lower. If it is hardware controlled then nothing can be done with this generation.

As I mentioned in one of my threads, dust becomes a big issue. Sucking in dust, contamination issues during the limited warranty. If you give control to the user. Denon will have a higher failure rate, short term due to dust. This is why,, I believe the fans come on ONLY at critical state, just prior to a thermal shut down. You should request white papers for these systems.

 

[amirm]

As I mentioned in one of my threads, dust becomes a big issue. Sucking in dust, contamination issues during the limited warranty. If you give control to the user. Denon will have a higher failure rate, short term due to dust. This is why,, I believe the fans come on ONLY at critical state, just prior to a thermal shut down. You should request white papers for these systems.

If you are going to have a fan on a device, then you best think of these things in your design. And I don't agree that accumulated dust over time is the same as heat generated all the time relative to reliability. AVRs have ton of electrolytic capacitors that have far shorter life when heated up. Dust doesn't impact them one bit. Even tiniest amount of active air movement has amazing cooling effect compared to just relying on convection.

 

[Bello]

If you are going to have a fan on a device, then you best think of these things in your design. And I don't agree that accumulated dust over time is the same as heat generated all the time relative to reliability. AVRs have ton of electrolytic capacitors that have far shorter life when heated up. Dust doesn't impact them one bit. Even tiniest amount of active air movement has amazing cooling effect compared to just relying on convection.

Denon can not control the environment these systems end up running. Dust build up contributes to additional heat. Over time contributing to component failure. Based on my extensive h/w experience, this is a fact.

 

[valerianf]

Well, it seems that an additional fan+durst filter is a solution for Denon users.
I live in California and have a 10 years old Yamaha.
There is no fan inside it but I always can place my hand at the top of the amplifier.
The top cover is warm but not hot, even in summer time.
This temperature issue and the down-mixing bug are the 2 points that stop me for placing a 3700h order.
It would have been my first Denon.

 

[theory]

Doesn’t the amount of heat also depends on how hard you intend to drive the amps as well? I would suspect if running way below reference should generate less heat?

 

[carlob]

These devices are meant to be disposable, it's not like vintage amps. Nobody is keeping an AVR for 5 years, let alone 10.
Every year the industry comes up with a new gizmo and you are compelled to upgrade because hey, I can't live without the new Atmos Turbo codec and 16 more channels embedded in the sofa. So even if it fails after a couple of years who cares.

 

[Urgo]

These devices are meant to be disposable, it's not like vintage amps. Nobody is keeping an AVR for 5 years, let alone 10.
Every year the industry comes up with a new gizmo and you are compelled to upgrade because hey, I can't live without the new Atmos Turbo codec and 16 more channels embedded in the sofa. So even if it fails after a couple of years who cares.

You're very wrong. Now I was about to change my 2006 Denon 4306, working as the first day with its Hdmi 1.3.
I know many who do not change every two years, most wait 5 years or more if they are satisfied with their receiver. The format changes that can occur in two years do not usually justify the change. Moreover, there is a gap between the emergence of these formats and their actual standardization and practical application, for example precisely Atmos, or the recent hdmi 2.1 and 8k images, of which there are no players, games or movies yet.

 

[carlob]

You're very wrong. Now I was about to change my 2006 Denon 4306, working as the first day with its Hdmi 1.3.
I know many who do not change every two years, most wait 5 years or more if they are satisfied with their receiver. The format changes that can occur in two years do not usually justify the change. Moreover, there is a gap between the emergence of these formats and their actual standardization and practical application, for example precisely Atmos, or the recent hdmi 2.1 and 8k images, of which there are no players, games or movies yet.

ok, let's see: 4K is a thing of when, 2013? I believe Netflix became streaming 4K stuff during 2014 so you missed six years of high resolution already. Before of that I don't even remember if in 2006 we already had widespread 16:9 TVs let alone HD resolution but in any case Hdmi 1.3 means 1080p. New audio codecs from 2006 to 2020? Plenty.

Now I don't know anybody and I mean literally zero, none, nil owning an AVR (or a tv for what it matters) that old. If you think that people change their A/V stuff every 15 years I think you are very wrong. Denon would be belly up with a 15 years upgrade cycle. I try to keep some discipline on upgrades but still I think that for AVRs you basically have to upgrade after 3/4 years, maybe a bit more for TVs and a lot more for projectors (mine is a 2013 HD projector but thinking to get a 4k one very soon).

 

[carlob]

I just checked my email and turns out I got my Pioneer Kuro PDP-LX5090 in 2008, that was the best plasma tv on the market at the time and was a 50" HD ready, now I have a 4K 75" Oled TV and there were many AVRs/TVs in between in only 12 years.

 

[Darvis]

ok, let's see: 4K is a thing of when, 2013? I believe Netflix became streaming 4K stuff during 2014 so you missed six years of high resolution already. Before of that I don't even remember if in 2006 we already had widespread 16:9 TVs let alone HD resolution but in any case Hdmi 1.3 means 1080p. New audio codecs from 2006 to 2020? Plenty.

Now I don't know anybody and I mean literally zero, none, nil owning an AVR (or a tv for what it matters) that old. If you think that people change their A/V stuff every 15 years I think you are very wrong. Denon would be belly up with a 15 years upgrade cycle. I try to keep some discipline on upgrades but still I think that for AVRs you basically have to upgrade after 3/4 years, maybe a bit more for TVs and a lot more for projectors (mine is a 2013 HD projector but thinking to get a 4k one very soon).

I check second hand ads from time to time and the majority of AVR there are quite old, 10 years easily. I think like Urgo that people keep them much longer than an enthusiast who is active on audio fora could imagine

 

[Urgo]

ok, let's see: 4K is a thing of when, 2013? I believe Netflix became streaming 4K stuff during 2014 so you missed six years of high resolution already. Before of that I don't even remember if in 2006 we already had widespread 16:9 TVs let alone HD resolution but in any case Hdmi 1.3 means 1080p. New audio codecs from 2006 to 2020? Plenty.

Now I don't know anybody and I mean literally zero, none, nil owning an AVR (or a tv for what it matters) that old. If you think that people change their A/V stuff every 15 years I think you are very wrong. Denon would be belly up with a 15 years upgrade cycle. I try to keep some discipline on upgrades but still I think that for AVRs you basically have to upgrade after 3/4 years, maybe a bit more for TVs and a lot more for projectors (mine is a 2013 HD projector but thinking to get a 4k one very soon).

At no point did I say that you have to wait 15 years to change the receiver.
I do know many who change about every 5 years, most of them, and very few who change every year or every two years.

My TV was until recently a Sony FHD 16:9, and so was the projector. Now I have changed to 4k and I will renew the receiver as well. Although there are obvious differences, I haven't missed as much as you say, except Atmos in the last few years, and there weren't many movies to choose from until recently.

Let everyone do what they want and can with their wallet, but don't say it's enough that the receivers last two years, there are more people in this world.

 

[Urgo]

I check second hand ads from time to time and the majority of AVR there are quite old, 10 years easily. I think like Urgo that people keep them much longer than an enthusiast who is active on audio fora could imagine

Sorry about the translator.
I'm usually aware of all the innovations and I'm also an audio enthusiast and very active in the audio forums, the proof is that I'm here.