Denon AVR-X4800H AVR Review

[peng]

I have a slight hum coming from the X4800H whenever it's on. In standby mode it's completely silent. I've tried disconnecting everything except the power chord, but it still hums when powered on. Is this to be expected?

When you say "slight", I don't know if it means it still bothers you when watching movies and listening to music from your nearest seating positions. None of my Denon AVRs had hum that could be audible from even a few inches away, and I am very sensitive to hum and could hear transformer hum from my separate power amps (normal, because of their much larger toroidal transformers). The main power transformers of AVRs aren't that big so if well-made like D+M's, should be near silent.

So, to me, if you can hear the hum of the transformer only when your ears are touching or almost touching the unit, then it is normal. If you could hear it from inches away, then I would exchange it for another one, while you are still within the return/exchange window.

 

[antcollinet]

No reason to accept hum on a new unit. If it was mine I would return it. My 4700 does not hum at all.

Like I say above - it can be caused by DC offset on the mains resulting in hum from the mains transformer. If this is the case, not much to be done for it other than get a DC filter for the supply. More than likely a replacement would do the same.

I guess no harm in trying a replacement though in case it is a result of a poor quality unit.

 

[techsamurai]

Here are a few improvements that can be made to the 4800h:

1. An auto-display off which shows information and goes dark
2. A backlit better remote - come on, this is absolute cheeseland especially compared to the Cinema 70's remote
3. More presets - the RZ50 has 3 so aim for that bar
4. Ability to move up and down continuously in Option menu - it's annoying to have to go down all the way to reach Preset
5. Addition of Audyssey DEQ (on/off) in Option menu
6. More curve options (4-5) with 3 minimum centering on midrange choices (leaner/beefier, more present) as tone controls can affect bass and treble so there's no need to control them via curve as much
7. Silver option (looks gorgeous on a video)
8. Fixing Arc sound dropout issues caused by new firmware update (very annoying)

Of all these #6 is the most important by a factor of 1,000,000% over the rest. The ability to finetune Audyssey without knowledge of REW and the apps or Pro versions would validate Amir's technical findings which do not take into account the sound people will hear once Audyssey is running and it would benefit all D+M owners massively. Once Audyssey runs you either accept it or not.

Like TVs give us choices so we can pick the mode we like. I like the calibration aspect of creating your own curve but most folks won't get there.

 

[rvsixer]

This Denon X4800 is a nice piece of kit, love having these ASR reviews available!
I just finished the initial build-out and basic manual calibration of my new 5.4.4 home theater with it, sounds awesome. My first personal Atmos build, the bubble of sound takes things to a whole new level than base layer alone (I think the best decision I made here was to not go with typical way-off-listening-axis ceiling/flat mounted top speakers; but to use high output/low compression bookshelves on 3-axis mounts allowing proper dispersion aiming/time intensity trading across the listening area).

Now onto MultiEQ-X / REW / SACT calibration fun ...

 

[evert]

So.. just to be clear, when you power on your AVR - it's dead silent?

(my X4800H is humming like I mentioned, and all my other gear is totally silent)

 

[Steve Dallas]

So.. just to be clear, when you power on your AVR - it's dead silent?

(my X4800H is humming like I mentioned, and all my other gear is totally silent)

Mine is dead silent.

 

[techsamurai]

Mine is dead silent.

Mine too as were the RZ50, Cinema 70, and 8002. Even with interconnects, I don't hear hum.

 

[peng]

Gents, all such small, but large enough (say >500 VA power transformers) transformers will hum, though the high quality ones such as those found on D+M mid range AVRs should be near silent. Even then, if you have your ears touching the enclosure or within an inch from it, you will hear a very slight hum. The OP said even with nothing connected, except the power supply cable, the slight hum is there, so it is 99% just transformer hum. Someone mentioned it could be due to high dc offset, but I doubt it because the op also said everything else (presumably share the same power source) were silent. Larger power transformers tend to hum more, try getting close to your neighborhood utility/distribution transformers, the noisier ones will likely be audible to most people even from 10 ft away.

Some people are more sensitive to the hum frequency, mainly 60, 120 Hz (NA), or 50, 100 Hz in Europe, Japan etc., others are not so they may not hear such slight hum unless they try hard to hear it.

As others mentioned too, it is normal!!

If it can be heard from say, even 1-2 ft away, then it would seem excessive, at least for D+M avrs. Practically speaking, even if it can be heard from a couple feet, it will be silent to the ears from typical seating distance of 8 to 20 ft in a quiet room, though in my opinion, it is better to request for a replacement.

 

[EWL5]

Doesn't it make a difference if the AVR is connected direct to outlet, to a line conditioner, or if a powerline ethernet adapter is part of the circuit?

 

[techsamurai]

Doesn't it make a difference if the AVR is connected direct to outlet, to a line conditioner, or if a powerline ethernet adapter is part of the circuit?

Hopefully, it's at least connected to a decent surge protector.

 

[peng]

Doesn't it make a difference if the AVR is connected direct to outlet, to a line conditioner, or if a powerline ethernet adapter is part of the circuit?

Unlikely, but if it us louder than normal due to excessive dc offset, then some line condtioners that can reduce dc offset may help.

Transformer hum

From the Naim Amplifier manual: A hi-fi system usually shares a mains circuit with other household equipment some of which can cause distortion of the mains waveform. This distortion can in turn lead to mechanical hum from mains transformers. Some Naim transformers are large in size, making...

community.naimaudio.com

 

[techsamurai]

Unlikely, but if it us louder than normal due to excessive dc offset, then some line condtioners that can reduce dc offset may help.

Transformer hum

From the Naim Amplifier manual: A hi-fi system usually shares a mains circuit with other household equipment some of which can cause distortion of the mains waveform. This distortion can in turn lead to mechanical hum from mains transformers. Some Naim transformers are large in size, making...

community.naimaudio.com

Peng, does it make a difference if I have a 20A vs 15A outlet? I know they'd said something like that on Audioholics about the 8500ha getting 10% more power with 20A.

 

[peng]

Peng, does it make a difference if I have a 20A vs 15A outlet? I know they'd said something like that on Audioholics about the 8500ha getting 10% more power with 20A.

What is the outlet used for? If it is for a single SR8002, then no it won't make a difference. If you know the maximim draw by each of the devices powered by the outlet, you can calculate the total draw based on the worst case scenario.

Regardless, if you have a choice, such as getting your house built, go with 20 A circuits for your HT room.

 

[Svend P]

Peng, does it make a difference if I have a 20A vs 15A outlet? I know they'd said something like that on Audioholics about the 8500ha getting 10% more power with 20A.

No. Both circuit breakers have an impedance close to zero (it is around 0.01 ohm), and none of them will act as voltage or current limiting for your AVR

 

[techsamurai]

No. Both circuit breakers have an impedance close to zero (it is around 0.01 ohm), and none of them will act as voltage or current limiting for your AVR

I think Europe has more power per outlet.

 

[techsamurai]

What is the outlet used for? If it is for a single SR8002, then no it won't make a difference. If you know the maximim draw by each of the devices powered by the outlet, you can calculate the total draw based on the worst case scenario.

Regardless, if you have a choice, such as getting your house built, go with 20 A circuits for your HT room.

Yeah, TV, sub, avr, (well 2 now but one in pre-amp mode), consoles or video devices.

The other devices other than sub and Avrs top out at 400-450 watts maybe.

 

[andyhi]

I have a slight hum coming from the X4800H whenever it's on. In standby mode it's completely silent. I've tried disconnecting everything except the power chord, but it still hums when powered on. Is this to be expected?

New X4800H, purchased a week or so back from ADORAMA. Very slight low frequency hum when powered on. Can only be heard if within 3 - 4 inches of the internal transformer and the room is completely silent.

This is nothing I wouldn’t expect out of any sort of powered on electronics with a transformer of this size. I have older receivers, including a 4200 with similar ever so slight transformer hum.

The hum is caused by magnetic / electric field flux vibrating the metal plates in the transformer. All transformers of this type have hum due to the physics involved… it’s just a matter of how much noise is emitted by the resonation. Those saying their’s doesn’t hum in these circumstances have hearing loss

If the hum is only a very slight back ground noise at ~12 - 24 inches inches or so - You might want to try see if you get different results out of mains power at another location serviced by a different distribution line or perhaps temporarily connect to a UPS in battery mode (preferably a pure sine model if you have one). If either of these make a significant difference, you should consider a power filter / conditioner. If the hum is audible at more than ~3 feet, I’d see about swapping the unit as the main power transformer might not be within manufacturing tolerances.

 

[andyhi]

I think Europe has more power per outlet.

Most of the EU has 220V outlets. P = V * I. So yes, average EU outlets / branch circuits can deliver about twice the power as US 110v circuits using similar size wiring at similar distances.

 

[Svend P]

I think Europe has more power per outlet.

Circuit breaker size has nothing to do with how much power your amplifier can or will consume. If you consume more than the rating of the circuit breaker, it will simply shut off. But there is no limitation on power up to that point.

 

[techsamurai]

Circuit breaker size has nothing to do with how much power your amplifier can or will consume. If you consume more than the rating of the circuit breaker, it will simply shut off. But there is no limitation on power up to that point.

Most outlets in the US are 15A so they have a maximum of 1800 watts. Clas A/B amps like the 4800h have a rating of 660 watts or so but they can actually draw more because of the inefficiencies of Class A/B - I think some can draw a theoretical 1,600 watts. If have a console that's 250 watts, a tv ~100-200 watts and the sub can be an issue since they have massive RMS and peak power ratings.

I would not have been worried with an AVR + sub but I'm definitely worried about 2 AVRs + sub