Denon AVR-X3800H Review

[allendsup23]

I am planning to buy Emotiva basx A3 which has input of 1.25v for max rated output. Does Denon X3800h output 1.25 v if I select pre out only for front LCR?
Want to figure out if I will be able utilize external amp fully.
I am new to this so got confused in the review which says 0.8v.

 

[peng]

I am planning to buy Emotiva basx A3 which has input of 1.25v for max rated output. Does Denon X3800h output 1.25 v if I select pre out only for front LCR?
Want to figure out if I will be able utilize external amp fully.
I am new to this so got confused in the review which says 0.8v.

You will get much higher than 1.25 V, even 4 V, pre amp mode makes no difference but it will keep distortions at lower level at above 1.4 to 2 V. If the review says 0.8 V, it simply mean it was 0.8 V when distortions was at or near the lowest point. There are other amps you can consider too, such as Monolith's, buckeye amps, VTV amps, Nord amps. Those class D amps are smaller, lighter, run cooler and may offer more outputs than the Bass X A3 that are good to take the load off the AVR but they don't offer more output than the AVR's own amps.

 

[srekal34]

I just bought the avr and I am sufferring from humming noise from the subwoofers (connected to Hypex ncore nc252mp module via monoprice rca to xlr cable).
So far I've investigated:

-Changing to tisino cables did not help

-hum increases with avr volume

-disconnecting the rca takes away hum completely

-connecting the amp with no ground pin did not help

-changing the wall outlet doesnt help

What else can I try?

 

[antcollinet]

I just bought the avr and I am sufferring from humming noise from the subwoofers (connected to Hypex ncore nc252mp module via monoprice rca to xlr cable).
So far I've investigated:

-Changing to tisino cables did not help

-hum increases with avr volume

-disconnecting the rca takes away hum completely

-connecting the amp with no ground pin did not help

-changing the wall outlet doesnt help

What else can I try?

Your setup is not clear to me.

AVR to amps to subs (so passive subs?)

or AVR to amps to subs with high level connection to powered subs?

What is your source?

Are you able to make up your own cable (you may get some benefit if you are able to solder up an RCA to XLR cable in a pseudo differential mode.)

 

[dlaloum]

According to my measurements, if bass management is turned on, i.e. any speakers set to small and any crossover set, it is converted to digital no matter what mode is selected.

All audio management bass/EQ, any decoding, mixing, etc... is digital - so it requires either digital transfer to the prepro, or ADC conversion within the prepro...

 

[srekal34]

Your setup is not clear to me.

AVR to amps to subs (so passive subs?)

or AVR to amps to subs with high level connection to powered subs?

What is your source?

Are you able to make up your own cable (you may get some benefit if you are able to solder up an RCA to XLR cable in a pseudo differential mode.)

Sorry, forgot to mention. Subs are passive(diy). I can solder, do you have a link to this method by any chance?

 

[antcollinet]

Sorry, forgot to mention. Subs are passive(diy). I can solder, do you have a link to this method by any chance?

Like this:

Pseudo-Differential Cable: RCA-to-XLR Cable | Neurochrome

Build your own pseudo-differential cable so you can connect your unbalanced (single-ended) sources to balanced (differential) inputs.

neurochrome.com

 

[srekal34]

Like this:

Pseudo-Differential Cable: RCA-to-XLR Cable | Neurochrome

Build your own pseudo-differential cable so you can connect your unbalanced (single-ended) sources to balanced (differential) inputs.

neurochrome.com

Thank you. If I understand correctly, this is how Benchmark xlr to rca cable is wired as well?

 

[antcollinet]

Thank you. If I understand correctly, this is how Benchmark xlr to rca cable is wired as well?

I'm not familiar with benchmark cables, but in any case you can't do it with XLR to RCA if this is what you meant (except in the rare cases an xlr output is transformer coupled)

 

[srekal34]

I'm not familiar with benchmark cables, but in any case you can't do it with XLR to RCA if this is what you meant (except in the rare cases an xlr output is transformer coupled)

This is the cable I mentioned:

Benchmark RCA to XLRM Adapter Cable for Analog Audio - pin 3 to RCA shield

BENCHMARK STUDIO STAGE™ RCA TO XLRM ADAPTER CABLE CABLES ARE SOLD INDIVIDUALLY. Price is for one cable, order 2 for a stereo pair. Hand assembled in the USA with true silver solder Applications This special adapter cable connects unbalanced analog RCA outputs to balanced analog XLR inputs. Use...

benchmarkmedia.com

Seems to be wired the same as in the link you've provided?

 

[antcollinet]

This is the cable I mentioned:

Benchmark RCA to XLRM Adapter Cable for Analog Audio - pin 3 to RCA shield

BENCHMARK STUDIO STAGE™ RCA TO XLRM ADAPTER CABLE CABLES ARE SOLD INDIVIDUALLY. Price is for one cable, order 2 for a stereo pair. Hand assembled in the USA with true silver solder Applications This special adapter cable connects unbalanced analog RCA outputs to balanced analog XLR inputs. Use...

benchmarkmedia.com

Seems to be wired the same as in the link you've provided?

Yes - sounds like that is the same.

 

[Moonbase]

These cables address the physical wiring issue, but not the XLR higher voltage requirement, while to some degree it works, its not ideal

 

[antcollinet]

These cables address the physical wiring issue, but not the XLR higher voltage requirement, while to some degree it works, its not ideal

That's just a gain issue - which exists however you connect RCA to XLR. This method however provides additional noise immunity.

 

[dfiler]

You will get much higher than 1.25 V, even 4 V, pre amp mode makes no difference but it will keep distortions at lower level at above 1.4 to 2 V. If the review says 0.8 V, it simply mean it was 0.8 V when distortions was at or near the lowest point. There are other amps you can consider too, such as Monolith's, buckeye amps, VTV amps, Nord amps. Those class D amps are smaller, lighter, run cooler and may offer more outputs than the Bass X A3 that are good to take the load off the AVR but they don't offer more output than the AVR's own amps.

I've been following your informative posts in this thread for almost two years. I had to do considerable reading just to gain enough knowledge to have a productive discussion. Thank you!

I am researching which class-D amp to buy. Part of the goal is increased/clean power when driving all channels. Another motivation is decreased heat generation from using the denon in preamp mode. I don't have air conditioning so cooling becomes an issue a few times each summer. Audio quality with the built-in amp sounds good to me until about -10dB, depending on source. Then it begins to sound a little harsh.

Setup:

• New amp to power all channels so x3800h can be in preamp mode
• Kef R3 = 87dB
• Kef R2c = 87dB
• Kef R8a = 86dB
• listening distance = 12 feet
• My typical movie volume = -15dB (+/-5dB)

How much of a limitation is the relatively low (clean) voltage of the denon preamp output to these class D amps? For example, Buckeye hypex NC252MP based amps claim 26dB voltage gain and input sensitivity of 1.6Vrms (4ohm) / 1.7Vrms (8ohm). There's a relatively low SINAD for that voltage range of the AVR.

But if a hypex NC502MP amp could be fed adequately, I'd opt for that or another similar, higher power class-d amp. Buckeye rates this at the same gain but input sensitivity 2.2Vrms (4ohm) / 2.7Vrms (8ohm). From my reading, the 3800 can output that much voltage but will have worse SINAD when turned up that high.

So what i'm trying to figure out is if I can run a NC502MP without losing audio quality. Given the same stated gain, is the higher voltage to reach max output simply a factor of the amp having a higher max output? If so, i'd buy the more powerful amp for future-proofing purposes. Or is it better to stick with the NC252MP?

 

[peng]

I've been following your informative posts in this thread for almost two years. I had to do considerable reading just to gain enough knowledge to have a productive discussion. Thank you!

I am researching which class-D amp to buy. Part of the goal is increased/clean power when driving all channels. Another motivation is decreased heat generation from using the denon in preamp mode. I don't have air conditioning so cooling becomes an issue a few times each summer. Audio quality with the built-in amp sounds good to me until about -10dB, depending on source. Then it begins to sound a little harsh.

Setup:

• New amp to power all channels so x3800h can be in preamp mode
• Kef R3 = 87dB
• Kef R2c = 87dB
• Kef R8a = 86dB
• listening distance = 12 feet
• My typical movie volume = -15dB (+/-5dB)

How much of a limitation is the relatively low (clean) voltage of the denon preamp output to these class D amps? For example, Buckeye hypex NC252MP based amps claim 26dB voltage gain and input sensitivity of 1.6Vrms (4ohm) / 1.7Vrms (8ohm). There's a relatively low SINAD for that voltage range of the AVR.

But if a hypex NC502MP amp could be fed adequately, I'd opt for that or another similar, higher power class-d amp. Buckeye rates this at the same gain but input sensitivity 2.2Vrms (4ohm) / 2.7Vrms (8ohm). From my reading, the 3800 can output that much voltage but will have worse SINAD when turned up that high.

So what i'm trying to figure out is if I can run a NC502MP without losing audio quality. Given the same stated gain, is the higher voltage to reach max output simply a factor of the amp having a higher max output? If so, i'd buy the more powerful amp for future-proofing purposes. Or is it better to stick with the NC252MP?

Quick answer is, in my opinion, yes, go for it. Long answer with supporting info to follow, when I get home.

 

[srekal34]

I've been following your informative posts in this thread for almost two years. I had to do considerable reading just to gain enough knowledge to have a productive discussion. Thank you!

I am researching which class-D amp to buy. Part of the goal is increased/clean power when driving all channels. Another motivation is decreased heat generation from using the denon in preamp mode. I don't have air conditioning so cooling becomes an issue a few times each summer. Audio quality with the built-in amp sounds good to me until about -10dB, depending on source. Then it begins to sound a little harsh.

Setup:

• New amp to power all channels so x3800h can be in preamp mode
• Kef R3 = 87dB
• Kef R2c = 87dB
• Kef R8a = 86dB
• listening distance = 12 feet
• My typical movie volume = -15dB (+/-5dB)

How much of a limitation is the relatively low (clean) voltage of the denon preamp output to these class D amps? For example, Buckeye hypex NC252MP based amps claim 26dB voltage gain and input sensitivity of 1.6Vrms (4ohm) / 1.7Vrms (8ohm). There's a relatively low SINAD for that voltage range of the AVR.

But if a hypex NC502MP amp could be fed adequately, I'd opt for that or another similar, higher power class-d amp. Buckeye rates this at the same gain but input sensitivity 2.2Vrms (4ohm) / 2.7Vrms (8ohm). From my reading, the 3800 can output that much voltage but will have worse SINAD when turned up that high.

So what i'm trying to figure out is if I can run a NC502MP without losing audio quality. Given the same stated gain, is the higher voltage to reach max output simply a factor of the amp having a higher max output? If so, i'd buy the more powerful amp for future-proofing purposes. Or is it better to stick with the NC252MP?

You wont lose anything going for 502mp with the same gain as 252mp. You will have the same power available at 1.6v(250W), but you will just have more headroom if needed.

 

[peng]

I've been following your informative posts in this thread for almost two years. I had to do considerable reading just to gain enough knowledge to have a productive discussion. Thank you!

I am researching which class-D amp to buy. Part of the goal is increased/clean power when driving all channels. Another motivation is decreased heat generation from using the denon in preamp mode. I don't have air conditioning so cooling becomes an issue a few times each summer. Audio quality with the built-in amp sounds good to me until about -10dB, depending on source. Then it begins to sound a little harsh.

Setup:

• New amp to power all channels so x3800h can be in preamp mode
• Kef R3 = 87dB
• Kef R2c = 87dB
• Kef R8a = 86dB
• listening distance = 12 feet
• My typical movie volume = -15dB (+/-5dB)

How much of a limitation is the relatively low (clean) voltage of the denon preamp output to these class D amps? For example, Buckeye hypex NC252MP based amps claim 26dB voltage gain and input sensitivity of 1.6Vrms (4ohm) / 1.7Vrms (8ohm). There's a relatively low SINAD for that voltage range of the AVR.

But if a hypex NC502MP amp could be fed adequately, I'd opt for that or another similar, higher power class-d amp. Buckeye rates this at the same gain but input sensitivity 2.2Vrms (4ohm) / 2.7Vrms (8ohm). From my reading, the 3800 can output that much voltage but will have worse SINAD when turned up that high.

So what i'm trying to figure out is if I can run a NC502MP without losing audio quality. Given the same stated gain, is the higher voltage to reach max output simply a factor of the amp having a higher max output? If so, i'd buy the more powerful amp for future-proofing purposes. Or is it better to stick with the NC252MP?

Let's just use the R3 as an example, the same rationale would apply to the R2C, R8a as well.

R3 can produce 87 dB, 2.83 V at 1 meter, that would be about 76 dB at 12 ft.

To add 20 dB for the peak per THX, you will need 10X the voltage, that is 28.3 V, or 200 W into 4 ohms.

The buckeyeamp 6 Ch NC502MP measured about 83.2 dB SINAD at 313 W into 4 ohms

The voltage required for 313 W into 4 ohms:

Vo = SQRT(313*4) = 35.38 V. Vo is the power amp output voltage

Vin = Vo/(10^(Vg/20)), Vg is the gain, Vin is the power amp input voltage, or the Preamp/dac output voltage.

So Vin = 35.38/(10^25.5/20), that's assuming the buckeye amp gain is 25.5 dB.

Vin = about 1.88 V.

Now look at the AVR-X3800H's SINAD vs output voltage curve:

SINAD at that output level is about 87 dB.

Next, look at the buckeye NC502MP's SINAD vs output level curve:

At 313 W, that is, output voltage of 35.38 V, or pre out voltage of 1.88 V, SINAD is about 83.2 dB.

So I don't think you will lose much performance in matching the buckeye amp with the AVR-X3800H used as preamp/dac in terms of pre out SINAD and NC502MP SINAD.

Also, keep in mind that:

1) with the AVR-X3800H output 1.88 V, you are driving the the 6 ch buckeye NC502MP to output 313 W into 4 ohms, if you currently listen to the AVR at volume -15, with the lower gain buckeyeamp, you would have to turn it up to about -12 for the same SPL.

2) At -12, the pre out voltage for digital input level at say 0 dBFS will be much lower than 1.88 V. Based on Amir's test, at 82, that is +2 in the relative scale, the output was about 2 V, so at 76, that is -4, it will be 1 V, and at -10 it will be about 0.5 V.

So, based on you listening now at volume -15, you may never have push the AVR to anywhere near 1.88 V. Using the buckeyeamp will however, give you the ability to crank it up to -6 or even 0, without worry about clipping during the highest peaks in movies.

One other thing about SINAD shown in those test is that it is for 1 kHz signal. At higher frequencies such as 5 kHz, 10 kHz test signal, SINAD will drop a few dB, you can look at those curves too, if you are interested.

 

[dfiler]

You wont lose anything going for 502mp with the same gain as 252mp. You will have the same power available at 1.6v(250W), but you will just have more headroom if needed.

Ah good, that's as I thought but wanted to confirm since I'm still part way through the learning curve.

...
R3 can produce 87 dB, 2.83 V at 1 meter, that would be about 76 dB at 12 ft.
To add 20 dB for the peak per THX, you will need 10X the voltage, that is 28.3 V, or 200 W into 4 ohms.
...
The voltage required for 313 W into 4 ohms:
SINAD at that output level is about 87 dB.
...
Next, look at the buckeye NC502MP's SINAD vs output level curve:
At 313 W, that is, output voltage of 35.38 V, or pre out voltage of 1.88 V, SINAD is about 83.2 dB.

So I don't think you will lose much performance in matching the buckeye amp with the AVR-X3800H used as preamp/dac in terms of pre out SINAD and NC502MP SINAD.
...
Also, keep in mind that:

1) with the AVR-X3800H output 1.88 V, you are driving the the 6 ch buckeye NC502MP to output 313 W into 4 ohms, if you currently listen to the AVR at volume -15, with the lower gain buckeyeamp, you would have to turn it up to about -12 for the same SPL.

2) At -12, the pre out voltage for digital input level at say 0 dBFS will be much lower than 1.88 V. Based on Amir's test, at 82, that is +2 in the relative scale, the output was about 2 V, so at 76, that is -4, it will be 1 V, and at -10 it will be about 0.5 V.

So, based on you listening now at volume -15, you may never have push the AVR to anywhere near 1.88 V. Using the buckeyeamp will however, give you the ability to crank it up to -6 or even 0, without worry about clipping during the highest peaks in movies.

One other thing about SINAD shown in those test is that it is for 1 kHz signal. At higher frequencies such as 5 kHz, 10 kHz test signal, SINAD will drop a few dB, you can look at those curves too, if you are interested.

Thank you for sharing your knowledge so thoroughly! I'll have to read your post another 10 times to commit these concepts to memory. I trimmed the quoted post a bit to highlight a couple things that I need to understand better.

It took me a bit to understand why you were talking about 2.83v. Ah... 1 watt per how driver sensitivity is measured at 8ohm. Translating that to 76dB at my listening distance makes sense. How does this lead to the next reasoning: "To add 20 dB for the peak per THX, you will need 10X the voltage, that is 28.3 V, or 200 W into 4 ohms." Is that referring to how consumer equipment is typically calibrated to a reference level of 75dB + 20dB for dynamic range?

Yet these speakers are rated at 8ohm with dips below 4ohm. Should these calculations be done at 8ohm instead of 4ohm?

Really, just knowing that the x3800h can reasonably drive Hypex modules is sufficient for ordering purposes. With how class-d amps have made massive power affordable, the x3800h is a good gateway receiver for those wanting more power now or at a later date. That is, if you're not on a quest to optimize SINAD. Other options are better in that regard. Overall, the x3800h is still an excellent balance of features for me. My aging ears might not even be capable of perceiving distortion at that level.

 

[peng]

Ah good, that's as I thought but wanted to confirm since I'm still part way through the learning curve.


Thank you for sharing your knowledge so thoroughly! I'll have to read your post another 10 times to commit these concepts to memory. I trimmed the quoted post a bit to highlight a couple things that I need to understand better.

It took me a bit to understand why you were talking about 2.83v. Ah... 1 watt per how driver sensitivity is measured at 8ohm. Translating that to 76dB at my listening distance makes sense. How does this lead to the next reasoning: "To add 20 dB for the peak per THX, you will need 10X the voltage, that is 28.3 V, or 200 W into 4 ohms." Is that referring to how consumer equipment is typically calibrated to a reference level of 75dB + 20dB for dynamic range?

Yet these speakers are rated at 8ohm with dips below 4ohm. Should these calculations be done at 8ohm instead of 4ohm?

Really, just knowing that the x3800h can reasonably drive Hypex modules is sufficient for ordering purposes. With how class-d amps have made massive power affordable, the x3800h is a good gateway receiver for those wanting more power now or at a later date. That is, if you're not on a quest to optimize SINAD. Other options are better in that regard. Overall, the x3800h is still an excellent balance of features for me. My aging ears might not even be capable of perceiving distortion at that level.

The 76 dB is the calculated spl you can expect at 12 ft, your seating distance, at 2.83V. It has nothing to do with your rest of the calculations, that was to find the voltage required for the amp to output the maximum output of 313 W as shown by Amir, based on the 83.2 dB SINAD he found on the curve.

I will follow up tomorrow with more details.

 

[G-Can]

could you do same calcs for Fosi V3/ZA3 with 48V Power supply? thank you in advance!