Denon AVR-X8500H AVR Review

[bigguyca]

Yes that would be my opinion, based on calculations. Take a look of it this way:

- The voltage gain of the X8500H's internal amp is about 29 dB (a little less I think..)
- The Purifi amp's gain is about 26 dB (a little less iirc..)

So the difference in gain is 3 dB and that means at the same volume position, the Purifi amp will output half that of the Denon's internal amp's. You will have to either re-run Audyssey, or manually increase the level settings by about 3 dB.

Once level matched, all will be good, except the pre out voltage will be 3 dB higher than that of the other channels that are using the internal amps.
That does not matter much because as shown in the SINAD vs pre out voltage, the X8500H has almost no degradation when the pre out voltage increases to 2 V and beyond.

It will be the same even if you use a separate preamp processor, except in this case the Purifi amp will benefit from the balance outputs that will have 2X the voltage of the unbalance outputs. Many other power amps (such Marantz, Yamaha's, and Bryston's etc.) won't benefit from the 2X balanced output voltage the same way the Purifi's will, because their gains are 6 dB lower for balanced inputs.

Not true for most Brystons

Most Bryston power amplifiers such as the 4B3, 7B3, 9B3, 21B3 and previous models such as the 4BSST2, have a choice of 23db or 29dB gain for either SE or XLR inputs. The 6BSST2 offers three gain settings including 29dB. A simple switch setting on the back of the amplifier controls the gain. This means that the gain is not 6dB lower when using the XLR (balanced) inputs for the models above, if the 29dB gain setting is used.

A choice of gain settings is an excellent feature of these amplifiers. This choice should be understood and not ignored.

 

[peng]

It looks like MCA-225 almost doubles the power from 8 to 4 ohms. The difference in weight is only 8 lbs between 2 channel models (Monolith being heavier but Anthem being longer). On used marked, I could get Anthem for $1400 vs the new Monolith for $1100 (free shipping).
Buckeye amp (NC502MP) beats them both in power, size, and $. I just don't have any experience with class D sound besides what comes inside the subwoofer(s).

Only 8 lbs difference? In that case I would probably go with the Monolith. The Anthem's power specs are impressive but you have to read their fine prints. It says 400 W 4 Ohms, 600 W 2 Ohms <1% THD, 1% in dB is 40 dB. It also does not say 2 channels driven so it most likely is 1 channel driven. The price for the Buckey amp seems like unbeatable. The 252 is likely more than enough, but to me, for a little more may as well go for the 502, not much difference in weight anyway.

Why are you recommending this calculator without adjustments?

As Crown clearly states in the link below the calculator you are recommending is for:

"The calculations discussed here apply to anechoic or outdoor conditions."

How Much Amplifier Power | Crown Audio - Professional Power Amplifiers

Crown is saying that the power requirements will be overstated by 6dB when the usage case indoors. 6dB means the calculator gives answers that are four times too large indoor/residential venues. 6dB is a factor or 4x for power.

This means that for example, if the calculator says that 100W are required then 25W would be required indoors. If 24W are required outdoors then 6W would be required indoors. This means that you take the output of the calculator you are recommending and divide by 4.

If you are going to recommend the Crown calculator then it would be good to include this adjustment information as well or the user will obtain answers that are far from accurate.

I just thought it is better to error on the safe side as people often forget those calculators are typically based on speaker sensitivities given in X dB/1W/1meter whereas speaker manufacturers specs are often based on 2.83V/1 meter, then there's the argument of how much room gain should allow, phase angles allowance etc. etc.

Regardless, you are right, I should have included that link.

I actually don't like any of the available online calculator and I made my own. Its done in Excel only at the moment (work in progress) so not very useful for forum members, yet..

 

[peng]

Not true for most Brystons

Most Bryston power amplifiers such as the 4B3, 7B3, 9B3, 21B3 and previous models such as the 4BSST2, have a choice of 23db or 29dB gain for either SE or XLR inputs. The 6BSST2 offers three gain settings including 29dB. A simple switch setting on the back of the amplifier controls the gain. This means that the gain is not 6dB lower when using the XLR (balanced) inputs for the models above, if the 29dB gain setting is used.

A choice of gain settings is an excellent feature of these amplifiers. This choice should be understood and not ignored.

I have the 4B SST so I am aware of that selector switch, but for "optimum" gain, the 2 V setting is recommended for use with Balanced input, and the gain would be 6 dB lower than if set to the 1 V setting that they recommend it for unbalanced input. That's just in general, obviously for advance users, one may pick their own based on their preamp's specs and/or just personal preference.

From the instruction manual:

 

[bo_knows]

Only 8 lbs difference? In that case I would probably go with the Monolith. The Anthem's power specs are impressive but you have to read their fine prints. It says 400 W 4 Ohms, 600 W 2 Ohms <1% THD, 1% in dB is 40 dB. It also does not say 2 channels driven so it most likely is 1 channel driven. The price for the Buckey amp seems like unbeatable. The 252 is likely more than enough, but to me, for a little more may as well go for the 502, not much difference in weight anyway.


I just thought it is better to error on the safe side as people often forget those calculators are typically based on speaker sensitivities given in X dB/1W/1meter whereas speaker manufacturers specs are often based on 2.83V/1 meter, then there's the argument of how much room gain should allow, phase angles allowance etc. etc.

Regardless, you are right, I should have included that link.

I actually don't like any of the available online calculator and I made my own. Its done in Excel only at the moment (work in progress) so not very useful for forum members, yet..

View attachment 128674

Why are you recommending this calculator without adjustments?

As Crown clearly states in the link below the calculator you are recommending is for:

"The calculations discussed here apply to anechoic or outdoor conditions."

How Much Amplifier Power | Crown Audio - Professional Power Amplifiers

Crown is saying that the power requirements will be overstated by 6dB when the usage case indoors. 6dB means the calculator gives answers that are four times too large indoor/residential venues. 6dB is a factor or 4x for power.

This means that for example, if the calculator says that 100W are required then 25W would be required indoors. If 24W are required outdoors then 6W would be required indoors. This means that you take the output of the calculator you are recommending and divide by 4.

If you are going to recommend the Crown calculator then it would be good to include this adjustment information as well or the user will obtain answers that are far from accurate.

Thank you for your input. I agree that I would need less power than what the Crown calculator showed.
According to this chart, I would need 64 Watts to reach THX 105 dB reference level if my speaker has a sensitivity of 87dB@1 Watt.
I'm listening to two speakers in a small/medium room size.

 

[peng]

Thank you for your input. I agree that I would need less power than what the Crown calculator showed.
According to this chart, I would need 64 Watts to reach THX 105 dB reference level if my speaker has a sensitivity of 87dB@1 Watt.
I'm listening to two speakers in a small/medium room size.

View attachment 128677View attachment 128677

If you want more precise numbers, it isn't as simple because you have to consider other factors including but not limited to the following:

- One speaker vs two speakers could make a difference of about 3 dB depending on room/placement, and contents.
- Room gain can be anywhere between 1 to 6 or more dB, some even argue to ignore it because it only/mainly affect the low frequencies.
- Amplifier headroom should be considered, would you want to size it to match what the calculator shows?
- Impedance complicates things further, as most online calculator don't let you enter the impedance (mine does, but its in Excel so no use to others).

The R500's impedance was specified by KEF as 88 dB/2.83V/1m. That's fine if you assume use its so called nominal impedance of 8 Ohms for the calculators, but if you want to be a little more realistic, you should probably based it on 4 Ohms, and the result would change by a factor of 2.

So then suddenly your table will show that you need more than 64 W to reach 105 dB, and now if you want an additional 3 dB headroom on hand, you would then need closer to 200 W.

Below is the impedance curve, the phase angle one looks benign so no issue there. You can see why I would rather do the calculations based on 4 Ohm impedance. In some case, such as some B&W speakers, if the phase angles look horrible enough, it could make another factor of 2 difference again.

As far as 1 speaker vs 2, that's a fair point and it would again make a difference of 3 dB (factor of 2), but if you want to stick with THX standard, then it is for 1 speaker. You can see why I tend to repeat myself, in saying that how much power one needs depends a lot on distance and your listening habits, i.e. your maximum desired SPL. As we know, 2X the power only gives you 3 dB more in SPL.

I have the R900, believe it or not, while the R900 are much bigger, I consider the R500 much harder to drive.

SoundStageNetwork.com | SoundStage.com - SoundStageNetwork.com | SoundStage.com

 

[bo_knows]

If you want more precise numbers, it isn't as simple because you have to consider other factors including but not limited to the following:

- One speaker vs two speakers could make a difference of about 3 dB depending on room/placement, and contents.
- Room gain can be anywhere between 1 to 6 or more dB, some even argue to ignore it because it only/mainly affect the low frequencies.
- Amplifier headroom should be considered, would you want to size it to match what the calculator shows?
- Impedance complicates things further, as most online calculator don't let you enter the impedance (mine does, but its in Excel so no use to others).

The R500's impedance was specified by KEF as 88 dB/2.83V/1m. That's fine if you assume use its so called nominal impedance of 8 Ohms for the calculators, but if you want to be a little more realistic, you should probably based it on 4 Ohms, and the result would change by a factor of 2.

So then suddenly your table will show that you need more than 64 W to reach 105 dB, and now if you want an additional 3 dB headroom on hand, you would then need closer to 200 W.

Below is the impedance curve, the phase angle one looks benign so no issue there. You can see why I would rather do the calculations based on 4 Ohm impedance. In some case, such as some B&W speakers, if the phase angles look horrible enough, it could make another factor of 2 difference again.

As far as 1 speaker vs 2, that's a fair point and it would again make a difference of 3 dB (factor of 2), but if you want to stick with THX standard, then it is for 1 speaker. You can see why I tend to repeat myself, in saying that how much power one needs depends a lot on distance and your listening habits, i.e. your maximum desired SPL. As we know, 2X the power only gives you 3 dB more in SPL.

I have the R900, believe it or not, while the R900 are much bigger, I consider the R500 much harder to drive.

SoundStageNetwork.com | SoundStage.com - SoundStageNetwork.com | SoundStage.com
View attachment 128679

Hi Peng,
I really appreciate all your time, effort, and advice. I hope others will benefit from our exchange.
Agree, KEF R500 should be treated as a 4-ohm speaker.
I'm still thinking of ways to improve my room's acoustic but will most likely give the class D amplifier a shot due to the cost and performance. I also took into consideration your concern about AVR's heat as it runs very hot.

 

[peng]

Hi Peng,
I really appreciate all your time, effort, and advice. I hope others will benefit from our exchange.
Agree, KEF R500 should be treated as a 4-ohm speaker.
I'm still thinking of ways to improve my room's acoustic but will most likely give the class D amplifier a shot due to the cost and performance. I also took into consideration your concern about AVR's heat as it runs very hot.

I wonder if there are some that offers a 30 day return or something like that. Hard to beat the price of the buckeye amps though. There are the March Audio, NAD and ATI's but those are much more expensive. Now that the CAD has gone up a little, I may consider getting one myself, but I have so many amps already..

 

[patoulol]

I wonder if there are some that offers a 30 day return or something like that. Hard to beat the price of the buckeye amps though. There are the March Audio, NAD and ATI's but those are much more expensive. Now that the CAD has gone up a little, I may consider getting one myself, but I have so many amps already..

yes, and you could compare with your beautiful mcintosh!

thank you for your time! it's very nice

 

[Andysu]

^ I wonder if you switched off that certain mode setting which will increase level.

 

[walt99]

Quote:
"If you have read my previous reviews of AVRs, you know that I test the pre-amp output with and without amplifiers active (if there is such an option). I tried to do this with the 8500H but at first failed miserably. I set the amplifier config to "pre" which I thought would shut down all the amps. Performance was poor indicating the amps were probably still on. Discussing it with the owner, he suggested that I turn off the individual channels and set the Amp config to Custom. Doing that indeed turned off the amps resulting in much better DAC performance. I asked Denon about it but their engineering team is on holiday. The suggestion was that perhaps this is something that is fixed in later firmware revisions? I did not try to test that."

I own the A110 and was wondering how does one tell for certain if the internal amps are indeed off?
I'm currently running in "Custom" mode based on Amirs review/findings with all external amps.

 

[peng]

Quote:
"If you have read my previous reviews of AVRs, you know that I test the pre-amp output with and without amplifiers active (if there is such an option). I tried to do this with the 8500H but at first failed miserably. I set the amplifier config to "pre" which I thought would shut down all the amps. Performance was poor indicating the amps were probably still on. Discussing it with the owner, he suggested that I turn off the individual channels and set the Amp config to Custom. Doing that indeed turned off the amps resulting in much better DAC performance. I asked Denon about it but their engineering team is on holiday. The suggestion was that perhaps this is something that is fixed in later firmware revisions? I did not try to test that."

I own the A110 and was wondering how does one tell for certain if the internal amps are indeed off?
I'm currently running in "Custom" mode based on Amirs review/findings with all external amps.

Again, unless they did something different to the A110, the internal power amps are always "on" in the sense that they are still connected to the power supply rails.

It would have been less confusing if the terms "turned off", or "amps off" were not used in the beginning. In preamp mode, it is the signal line that gets "disconnected", that is, the power amp outputs inputs (edit: "outputs" was obviously a typo) are disconnected from the preamp outputs.

Some people may think that since the signal line is disconnected, the power amp will not get an input signal so there is nothing to amplifier and can therefore be considered as "off".

To find out if the internal power amp(s) is/are disconnected from the preamp outputs should be as simple as hooking up a speaker to the binding posts.

 

[walt99]

Again, unless they did something different to the A110, the internal power amps are always "on" in the sense that they are still connected to the power supply rails.

It would have been less confusing if the terms "turned off", or "amps off" were not used in the beginning. In preamp mode, it is the signal line that gets "disconnected", that is, the power amp outputs are disconnected from the preamp outputs.

Some people may think that since the signal line is disconnected, the power amp will not get an input signal so there is nothing to amplifier and can therefore be considered as "off".

To find out if the internal power amp(s) is/are off should be as simple as hooking up a speaker to the binding posts.

My interpretation of Amirs testing would imply that the amps are still getting an input signal even in preamp mode?
I agree, maybe hooking up a speaker would be the only way to tell if they are really on/off.
I understand the amps are still powered and I run with ECO mode ON to reduce rail voltage/idle power.

 

[peng]

My interpretation of Amirs testing would imply that the amps are still getting an input signal even in preamp mode?
I agree, maybe hooking up a speaker would be the only way to tell if they are really on/off.
I understand the amps are still powered and I run with ECO mode ON to reduce rail voltage/idle power.

I think so, but that's not right so either there is a bug in that unit or it had something to do with the settings. I wish he had done some trouble shooting. Do you have the X8500H or A110? If you do, would you mind doing a simple speaker test?

@Dj7675 , have you figured out what happened eventually?

 

[walt99]

I think so, but that's not right so either there is a bug in that unit or it had something to do with the settings. I wish he had done some trouble shooting. Do you have the X8500H or A110? If you do, would you mind doing a simple speaker test?

@Dj7675 , have you figured out what happened eventually?

I have the A110 and yes I will do a test at the next opportunity to see if I can tell what's going on.

 

[walt99]

I think so, but that's not right so either there is a bug in that unit or it had something to do with the settings. I wish he had done some trouble shooting. Do you have the X8500H or A110? If you do, would you mind doing a simple speaker test?

@Dj7675 , have you figured out what happened eventually?

Just did a quick check and center channel speaker terminal output does indeed go off when using either Pre-Amp mode or Custom mode with center set to off.
So guess I answered my own question. Maybe this was fixed in the A110 or the recent software update.

 

[bo_knows]

Just did a quick check and center channel speaker terminal output does indeed go off when using either Pre-Amp mode or Custom mode with center set to off.
So guess I answered my own question. Maybe this was fixed in the A110 or the recent software update.

Hi Walt, how do you like/compare the sound of AVR's internal amps vs AHB2? I assume you have this amp since it's listed under your equipment. Do you use the AVR as the pre-amp to AHB2? Thanks

 

[Dj7675]

I think so, but that's not right so either there is a bug in that unit or it had something to do with the settings. I wish he had done some trouble shooting. Do you have the X8500H or A110? If you do, would you mind doing a simple speaker test?

@Dj7675 , have you figured out what happened eventually?

I mentioned in the x8500 thread on AVS that the preamp mode was broken. I sent jdsmoothie (who seems to be very connected with Denon/Marantz) and he confirmed that a firmware had fixed it. I will see if I can find that post and see if he mentioned which firmware fixed it. It would be interesting to know if that firmware issue affected any other models preamp modes. I don't know of any bench tests to confirm it was fixed. My understanding is Denon didn't provide any follow up with @amirm on the issue. Since I use a mix of internal and external, I use custom amp assign and disconnect amps on the channels that I use external amplification on. If I used all external amplification, I would still use this method instead of full preamp mode wihtout any confirmation directly from Denon (but that's just me). It would be great if there was word directly from Denon that it is in fact fixed or a bench test, testing preamp mode on the x8500 or A110. Not sure if we will see that though...

 

[walt99]

Hi Walt, how do you like/compare the sound of AVR's internal amps vs AHB2? I assume you have this amp since it's listed under your equipment. Do you use the AVR as the pre-amp to AHB2? Thanks

Sorry but never bothered to do an A/B comparison, I purchased the A110 specifically to use as a AVR preamp (returned an Anthem AVM70) and the AHB2 to drive my 328's. I do love the way it sounds and have not been able to push the single AHB2 to ever light the clipping indicators despite a valent effort to see how loud it would go. I have a Buckeye 4ch amp coming in this week to finish things up with the center/surround channels.

 

[bo_knows]

Sorry but never bothered to do an A/B comparison, I purchased the A110 specifically to use as a AVR preamp (returned an Anthem AVM70) and the AHB2 to drive my 328's. I do love the way it sounds and have not been able to push the single AHB2 to ever light the clipping indicators despite a valent effort to see how loud it would go. I have a Buckeye 4ch amp coming in this week to finish things up with the center/surround channels.

Cool, thanks. If I owned AHB2 I wouldn't bother either.

 

[tparm]

Sorry but never bothered to do an A/B comparison, I purchased the A110 specifically to use as a AVR preamp (returned an Anthem AVM70) and the AHB2 to drive my 328's. I do love the way it sounds and have not been able to push the single AHB2 to ever light the clipping indicators despite a valent effort to see how loud it would go. I have a Buckeye 4ch amp coming in this week to finish things up with the center/surround channels.

Walt, just ordered an Audiolab 6000 CDT to run through the X16. I love that DAC. Found my box of old CDs and thought why not.

@bo_knows a Vette fan or associated with Corvette Racing?