Denon AVR-X3800H Review

[stupidvillager]

You do know there is a difference between a transducer and electronics?

Yes.

 

[Trell]

Yes.

Yet you asked your question not exactly showing that you did, I'd say.

 

[stupidvillager]

Yet you asked your question not exactly showing that you did, I'd say.

What question was that? I merely stated Amir has subjective reviews in with his speaker reviews. Which, speakers can sound different to different people.

 

[Trell]

What question was that? I merely stated Amir has subjective reviews in with his speaker reviews. Which, speakers can sound different to different people.

You “merely stated”?

You wrote

>>>I find in funny that people here live to clown on subjective reviews from other sources but every speaker review here has a subjective review attached to it.<<<

 

[stupidvillager]

You “merely stated”?

You wrote

>>>I find in funny that people here live to clown on subjective reviews from other sources but every speaker review here has a subjective review attached to it.<<<

Where is the question?

 

[GalZohar]

The same can most certainly happen with listening to an AVR. If you're saying this is impossible, and one can't detect distortion at high volume compared to other receivers without a blind test, then the measurements are moot, as it likely won't be detected in real world usage. ...provided you don't believe in "golden ears".

I'm not saying it's impossible to detect. I'm saying that in order to prove that you can detect it, you must do more than just listen and say that you heard it. How will I know he actually heard it and it wasn't just bias? How does he know?

 

[GaryH]

There is nothing extraordinary about saying distortion at these levels can be audible.

Then could you please link to evidence of distortion at these levels (such as exhibited by the AVR of this review) or below being successfully detected by listeners in blind tests? I think everyone would be very interested to see that.

 

[dlaloum]

The short answer.
It is not just an expense do design for amps that handle Lower impedances. It is more a choice.
It is a trade off. "Ohms law"

Years ago as explained by Harman Kardon.

HARMAN KARDON............

"There are two related but distinct limitations on the maximum instantaneous power output available from a given output-transistor configuration and load impedance. The maximum possible voltage output is determined by the amplifier’s internal DC power-supply voltage, which must not be allowed to exceed the transistors’ allowable maximum levels. There is also a limitation on the peak current that can be drawn by the load, which also must remain within the transistors’ rated operating range. The continuous power output (the product of the voltage and current) and the heat dissipated by the transistors must also be considered, but these are related to long-term operating conditions and are normally much lower than the peak levels.

In conventional amplifier designs, a choice has to be made between the maximum current-out-put and maximum voltage-output capabilities of the amplifier, as they relate to the load impedance. In order to develop 200 watts into an 8-ohm load, say, the maximum voltage must be 40 volts RMS combined with a current output of 5 amperes. For 200 watts into a 4-ohm load, only 28.3 volts is required, with a current of just over 7 amperes. If, however, a 40-volt maximum output is delivered into 4 ohms, the load will draw 10 amperes, corresponding to 400 watts— well beyond the amplifier’s design limits and probably those of the speaker as well. On the other hand, if an amplifier designed to drive 4-ohm loads to 200 watts is terminated in an 8-ohm load, it will only be able to supply 100 watts output."

Only by using a dual voltage power supply can an amp be optimized for both lower and normal impedances. Most amps use one supply voltage.

Umm yes - but this does not imply that an amp engineered to provide 40V @2ohm, will be unable to provide the same 40V@8ohm ...although it DOES imply that it will need to be more heavily engineered... and that this engineering, will be redundant when driving 8 ohm or 4 ohm loads - but there is nothing there that implies a reduced performance for an amp engineered that way, when driving "easier" loads.

Yes it is a cost tradeoff - but it isn't (necessarily) a performance tradeoff.

 

[CyrusTheGreat_600BC]

Then could you please link to evidence of distortion at these levels (such as exhibited by the AVR of this review) being successfully detected by listeners in blind tests? I think everyone would be very interested to see that.

“Everyone” who? You are good at generalizing your own ideas as others. I’m good with dropping one lousy AVR. If it sells well or not won’t gain me anything either way. Already voted with my wallet and will do it again until Denon comes to their senses.

 

[dlaloum]

There used to be a thing called a transformer that allowed multiple load impedance connections. Other than in PA systems, they are not used much.

Yeah - another piece of expensive engineering.... nothing wrong with it, but there are and were cheaper ways to skin that cat.... so it got dumped in the trash-heap of history

 

[dlaloum]

Right! But keep in mind, given a budget, one does have to compromise, or optimize two basic factors. That is choosing between the voltage limit and current limit. They have to minimize potential issues with high impedance peaks too if the optimize too much for current, that may result in the final design being voltage limited.

Or... over-engineered - and therefore expensive.... which pretty much describes most amps that have been capable of doubling down all the way to 2ohm or below!!

 

[beagleman]

Umm yes - but this does not imply that an amp engineered to provide 40V @2ohm, will be unable to provide the same 40V@8ohm ...although it DOES imply that it will need to be more heavily engineered... and that this engineering, will be redundant when driving 8 ohm or 4 ohm loads - but there is nothing there that implies a reduced performance for an amp engineered that way, when driving "easier" loads.

Yes it is a cost tradeoff - but it isn't (necessarily) a performance tradeoff.

Think about it some more.
I think you may be missing why it is important.
An amp that can deliver high current at low impedances, is not a cure all for all out performance at all impedances.

An output transformer will not be the cure either
Transistors operate within certain voltage and current ranges.
Any amp optimized to work good at low impedances, will by ohms law and logic will be limited in output with normal impedance speakers.

High current amps alone are not some magical cure for all things. They are simply better matched to LOW impedance loads.

A dual voltage power supply, is one of the few ways to optimize the amps performance at Normal OR lower impedances.
The power transistors and power supply will limit the power at either Low or Normal impedances.

There is no amp that makes good power at Both. It is one or the other. Unless of course you can vary the voltage delivered to the power transistors from the power supply.

It is a matter of over heating and overloading components.
An amp great at low impedances, by its very design will lose performance at higher or normal impedances.

 

[beagleman]

Right! But keep in mind, given a budget, one does have to compromise, or optimize two basic factors. That is choosing between the voltage limit and current limit. They have to minimize potential issues with high impedance peaks too if the optimize too much for current, that may result in the final design being voltage limited.

Mostly agree!
It becomes an issue of voltage versus current and transistors all have limitations.
Optimize for 8 ohms and it strains to do 4 ohm loads.
Optimize for 4 ohms, and it can not reach its full potential for 8 ohm loads.

in this case, a high current amp is not the same as just putting a huge engine in a car.

 

[Rottmannash]

I know, and agree with you to some extent. I still read subjective reviews though mainly for entertainment. Robinson's use of flowery words/jargonsare too over the top and is too serious to offer entertainment imo. Of course ymmv.

If you find his reviews verbose/flowery you may want to avoid 99% of the rest of them on YT. I find him at last tolerable, as opposed to some of the charlatans who masquerade as reviewers.

 

[Rottmannash]

Think about it some more.
I think you may be missing why it is important.
An amp that can deliver high current at low impedances, is not a cure all for all out performance at all impedances.

An output transformer will not be the cure either
Transistors operate within certain voltage and current ranges.
Any amp optimized to work good at low impedances, will by ohms law and logic will be limited in output with normal impedance speakers.

High current amps alone are not some magical cure for all things. They are simply better matched to LOW impedance loads.

A dual voltage power supply, is one of the few ways to optimize the amps performance at Normal OR lower impedances.
The power transistors and power supply will limit the power at either Low or Normal impedances.

There is no amp that makes good power at Both. It is one or the other. Unless of course you can vary the voltage delivered to the power transistors from the power supply.

It is a matter of over heating and overloading components.
An amp great at low impedances, by its very design will lose performance at higher or normal impedances.

Doesn't the AHB2 accomplish this?

 

[dlaloum]

Think about it some more.
I think you may be missing why it is important.
An amp that can deliver high current at low impedances, is not a cure all for all out performance at all impedances.

An output transformer will not be the cure either
Transistors operate within certain voltage and current ranges.
Any amp optimized to work good at low impedances, will by ohms law and logic will be limited in output with normal impedance speakers.

High current amps alone are not some magical cure for all things. They are simply better matched to LOW impedance loads.

A dual voltage power supply, is one of the few ways to optimize the amps performance at Normal OR lower impedances.
The power transistors and power supply will limit the power at either Low or Normal impedances.

There is no amp that makes good power at Both. It is one or the other. Unless of course you can vary the voltage delivered to the power transistors from the power supply.

It is a matter of over heating and overloading components.
An amp great at low impedances, by its very design will lose performance at higher or normal impedances.

Or you can add more transistors in parallel to allow greater load handling, increase heatsink sizes, to radiate the additional heat generated, increase the power supply size to allow for greater current AND voltage.

A number amps demonstrate the viability of this without compromise to sound quality:
Mark levinson 333 - 300W @ 8ohm 1200W@2ohm
Krell KSA200 - 200W@8ohm 1600W@1ohm

Quad 606: 135W@8ohm, 90W@2ohm
Crown XLS2500 440W@8ohm 775W@4ohm 1200W@2ohm
Hypex Nilai NC400 : 200W@8ohm 400W@4ohm 580W@2ohm

These last 3 are pretty typical of high quality amps... with limitations driven by current and thermals at the impedance extremes - still very capable at 2 ohms!

The first two demonstrate what is possible - the last 3 demonstrate what is typical in high quality amps - the former are cost no object designs, the latter are high quality, but good value designs.

Some more examples:

Simaudio moon 860A 225W@8ohm 450W@4 ohm 750@@2ohm
Purifi 1ET400 175W@8ohm 360W@4ohm 225W@2ohm
Gryphon Apex 210W@8ohm 420W@4ohm 800W@2ohm 1490W@1ohm

 

[dlaloum]

If you find his reviews verbose/flowery you may want to avoid 99% of the rest of them on YT. I find him at last tolerable, as opposed to some of the charlatans who masquerade as reviewers.

I've enjoyed his reviews over the years - and his recommendations have on occasion served me well! (at the very least they triggered further research on components that I otherwise would not have considered)

 

[dlaloum]

Doesn't the AHB2 accomplish this?

I'm pretty sure it does, but 2 ohm specs are a bit hard to find... I believe I read somewhere that it will self protect at 324W @ 2ohm
So it is not one of those expensive rarities that doubles down all the way - but it apparently handles 2 ohm and even 1 ohm very well...

 

[purrify]

Denon just dropped 3700H back to $1199 [denon's website]. Are the new 3800H features worth the $500 difference?

I like the addition of Dirac but that's additional. The more granular amp disconnect is also quite attractive because I'm planning to use the AVR to drive a 2 more speakers but the money could go to adding another 2ch amp like the Nilai DIY while running the 3700H in preamp mode.

Looking into the amp disconnect, I am also wonder if that is still possible if the 3800H had the 8ch AKM DAC? Can they still do amp disconnect by channel pair with a 8-ch DAC or is that only feasible with multiple 2-ch DAC?

 

[Turbo6]

I have an updated 6700h.

I use it for 5 monitor audio speakers in ceiling that are 6ohm 85w. I figure the 6700 is overkill and want to sell it for a Marantz cinema 50 due to the extra 2.1 and to use Dirac.

Will the c50, based on the 3800, be enough to handle these 5 speakers?