Denon AVR-X8500H AVR Review

[Michael YYZ]

If you think so, I suggest that you obtain the Service Manual for this receiver (AVR-4308CI) and study it yourself.
Imagine if you push 140 W into 300 Ohm cans w/o those resistors! Perhaps you could try and let us know what happens.

I think that diagram may be missing some details. 440 ohm output impedance seem way too high for headphones, as there are many headphones that have impedance less than 300 ohms, even 100 ohms.

 

[North_Sky]

If you shop, it can be had for less for sure.... $2700 delivered If you shop for an open box it can be had between $2800-$3000 for an authorized dealer and comes with the full manufacturer warranty (3year). Considering what you get, I think it makes for a good value for what you get.

It is sold out right now @ A4L ... refurb for $2,800 US.

Those are good deals too ...
• https://www.accessories4less.com/ma...7200wa-9.2-ch-x-150-watts-a/v-receiver/1.html

• https://www.accessories4less.com/ma...9.2-ch-x-125-watts-a/v-receiver-w/heos/1.html

 

[peng]

If you think so, I suggest that you obtain the Service Manual for this receiver (AVR-4308CI) and study it yourself.
Imagine if you push 140 W into 300 Ohm cans w/o those resistors! Perhaps you could try and let us know what happened.

I never said such a thing, but Is it possible that there is some sort of active attenuator in addition to those 2 resistors? I understand you got that image from the service manual so I am not disputing that part at all, just being curious and wonder if there are other parts not shown in the attached image that completes the circuitry, that's all.

 

[Vasr]

It is very nice to see at least some scaling of SINAD with respect to price.

I wonder if it is based on engineering costs to get up there or just product differentiation decisions. Perhaps a really big chassis helps separate out things better.

I wonder if @amirm pulled an all-nighter measuring this or too much trembling with excitement to type in a good review. Otherwise why would a 32-tone test be masquerading wearing mascara or distortion seeping into frequency?

Just a few typos caught my eye in case you want to edit later after the excitement has died down.

Dynamic range is nearly good enough to keep with with the SINAD:


As is 32-tone test mascaraing as music:


Which helps when we seep distortion versus frequency:

 

[peng]

It's perfectly normal and perfectly sensible. The higher the rated power of the amplifier, the larger those dropper resistors will need to be to keep the output level reasonable and the noise level as low as possible.

All these people wanting super low output impedance don't consider the safety aspect (ear damage and blown headphones in an instant) or residual noise. A power amplifier may have >50uV of residual noise (typical). Not only that, dedicated HP amps can maybe swing +/-13.5V (9.5V RMS) or maybe double that on a bridged output, but a 150W/ch amplifier would swing nearly +/-50V without series dropper resistors. Just how long do you think your HPs would last? All of a few milliseconds.

Here's another typical implementation:
View attachment 77810

And another:
View attachment 77811

If you want zero output impedance for your HPs. Buy a cute little HP amplifier or a receiver/amplifier that has a tacked on opamp HP stage. Otherwise enjoy the free HP output from the power amps via sensibly rated series resistors.

I am not wanting low output impedance but 440 ohms seem high as output impedance for H/P and I am just curious about if that image shows the full picture. It would be great to see the complete circuit. If it is what it is okay, fine but I would think using just resistor to drop the voltage is too dependent on the impedance of headphones that have a wide range, from under 100 ohm to as high as 300 ohms or higher.

 

[restorer-john]

I never said such a thing, but Is it possible that there is some sort of active attenuator in addition to those 2 resistors?

The volume control controls the level into the power amp. The power amp has a fixed gain. The output which normally feeds the speakers is dropped to a sensible level by the 440 ohm resistors to feed the H/Ps.

It's been done this way for >60 years. Then along came ultra high performance headphones and their companion low noise, low output, dedicated amplifiers.

 

[Vasr]

I think this deserves a golfing panther. It's the best so far.

It is not relative grading.

I suspect the amp performance for the price kept it from the top rating.

 

[Michael YYZ]

I cannot post entire copyrighted diagrams here due to obvious reasons but I can tell you that, other than the relais switching the output from speakers to headphones, there’s nothing else in the circuit. At some point the output is directed either directly to the speakers output, or to the headphones via the resistors.

In an AVR there’s more to the signal attenuation. Plugging in cans will also signal to the DSP to downmix the signal to stereo and remove room equalization.

I never said such a thing, but Is it possible that there is some sort of active attenuator in addition to those 2 resistors? I understand you got that image from the service manual so I am not disputing that part at all, just being curious and wonder if there are missing parts, that's all.

 

[peng]

The volume control controls the level into the power amp. The power amp has a fixed gain. The output which normally feeds the speakers is dropped to a sensible level by the 440 ohm resistors to feed the H/Ps.

It's been done this way for >60 years. Then along came ultra high performance headphones and their companion low noise, low output, dedicated amplifiers.

Again, if that's how it's done, okay. Not I would prefer, but as they say ymmv. I actually had a 4308, good thing I never used it with my headphones.

 

[Vasr]

What I'd like Denon to do is rip out the amps, add XLR pre-outputs and then would outperform the Marantz 8805.
Owners can then add however many channels of external (preferably clean class D) amplification they need.
I think most people willing to spend $4000 on an AVR would be open to separates.
Otherwise when it's time to update for the latest processing functionality which seems to happen every 3 years, at least you don't have to throw away all those amps with it.

Makes sense from a consumer perspective but not for Denon (or any AVR manufacturer)

Does not work for pricing and margins. Because the pre-pros are licensing costs heavy, the price of the equivalent pre/pro will need to be so close to the all-in-one that they would rather throw the amp in and keep the price differentiated above the next down the line. Otherwise, it will cannibalize the lower tier as well.

 

[peng]

I cannot post entire copyrighted diagrams here due to obvious reasons but I can tell you that, other than the relais switching the output from speakers to headphones, there’s nothing else in the circuit. At some point the output is directed either directly to the speakers output, or to the headphones via the resistors.

In an AVR there’s more to the signal attenuation. Plugging in cans will also signal to the DSP to downmix the signal to stereo and remove room equalization.

Thank you, that's all I need to hear, that the image shows the full picture.

 

[Michael YYZ]

It‘s certainly cheaper to add four resistors altogether than include a dedicated headphone amp.

Again, if that's how it's done, okay. Not I would prefer, but as they say ymmv. I actually had a 4308, good thing I never used it with my headphones.

 

[peng]

It‘s certainly cheaper to add four resistors altogether than include a dedicated headphone amp.

Fair point, though the 4308 wasn't cheap, I know how much I paid.

 

[amirm]

I wonder if it is based on engineering costs to get up there or just product differentiation decisions. Perhaps a really big chassis helps separate out things better.

I suspect it has to do with DAC choice. Essentially whatever they use, they wind up derating by about 10 dB due to internal gain structure. So the better the DAC+implementation, the higher the final SINAD. Better DACs cost a lot more so that is reflected in the price.

I wonder if @amirm pulled an all-nighter measuring this or too much trembling with excitement to type in a good review. Otherwise why would a 32-tone test be masquerading wearing mascara or distortion seeping into frequency?

Just a few typos caught my eye in case you want to edit later after the excitement has died down.

Corrected. I was supposed to get the headphone test rig this week so have been working frantically to get a few reviews done so I could focus on that. Alas, the ship is late so I have hurried up to wait...

 

[Anterantz]

Sí, estoy informado correctamente, el denon 8500h tiene estéreo dac akm 4490 en cada canal si tiene 13 canales imagino que tendrá 7 dac akm 4490 vs el multicanal akm 4458 en los rangos más bajos

 

[peng]

Amir, what is the easiest way to compare IMD that has the X-axis in power level vs the one you currently are using based on generator level in dBFS?

For example, in the graph below, what power levels in Watt would correspond to generator levels of -60, -30, -5 and 0 dBFS?

Thank you.

 

[Bello]

I didn't see anyone said the DAC was an earth shattering difference, but there it is definitely better. The difference in the x8500 and other Denon’s are easily found, many listed in this thread. Those differences plus the better performance are important to many, but it is certainly ok if they don’t matter to you. But don’t make the silly argument that the only difference is the DAC. For example if I didn’t want 13 channels of processing, Auro 3D, DTS Pro, dialogue enhancer, amp disconnect on all channels I too would go for the x3700 x4700 etc. YMMV

edit: x6700 I think is $2500 and 8500 is $4k. I see now you were comparing the 6700 to the 8500. They do share many things. difference is $1500. Plus with the issues of the 6700 as tested, that is all we know about it’s performance until it is fixed And retested.

The new X8500Ha will have a price tag at or around $4499 vs X6700H $2499. Part of my quote above that you were kind enough to pointed out, Thank you for the correction!!! I have a difference of $1500. My bad, difference will likely be $2000 for a 8500Ha. Thanks for pointing that out.

That said, I'm still trying to figure out where inside the 8500Ha $2K grand premium lies over the 6700H. Huge margin, that is all I'm saying.

If the 6700H comes within spec in the next go around test, I believe we'll see a clear best buy winner :+ )

Don't get me wrong. The 8500Ha is great in all it's glory. But at a steep price, average @ 137w (7) channel driven? The whole package is a quality product, sweet spot. My 6700H, w/ Emotiva a sweeter spot @ 275w (7) channel driven. Plus I have the option of using my internal 6700 amp for additional high output channels. Top that... under $4500

All in all, I'm extremely happy with the sound performance, even w/ the degraded caps. Which will be replaced in the coming weeks with a Newly spec'd 6700H.

Good luck!

 

[dubplate]

Hi @amirm - thanks for this review! I've joined as paid member to support ASR. I was waiting for this review to make my final purchase decision and Im off to buy my x8500 now.

Im going to run the x8500 on a dedicated 20 amp, 240 volt circuit - do you think I'll see any amplifier output gains over what you tested? what power/circuit did you test on?

Thanks

 

[Anterantz]

Hi @amirm - thanks for this review! I've joined as paid member to support ASR. I was waiting for this review to make my final purchase decision and Im off to buy my x8500 now.

Im going to run the x8500 on a dedicated 20 amp, 240 volt circuit - do you think I'll see any amplifier output gains over what you tested? what power/circuit did you test on?

Thanks

I just installed a dedicated 20A line and there are audible improvements at reference volume, I have never noticed my room sound so beast!

 

[amirm]

Hi @amirm - thanks for this review! I've joined as paid member to support ASR. I was waiting for this review to make my final purchase decision and Im off to buy my x8500 now.

Im going to run the x8500 on a dedicated 20 amp, 240 volt circuit - do you think I'll see any amplifier output gains over what you tested? what power/circuit did you test on?

Thanks

Thanks for the kind words. Our mains voltage here is around 120 volts. My circuit is capable of 20 amps. Total power with 5 channels driven was around 700 watts so well below the limit. This is with all 5 channels running continuously which you won't be doing. Net, net, you have have a tiny to no advantage with 240 volts.