O-Noorus D3 Pro Amplifier Review

[natna]

I think it's a missed opportunity...
HDMI ARC
AKM 4493 Chip
But SINAD not very good...

(Am I the only one, that when I see HDMI ARC support, I wonder if it has direct DSD?)

 

[amirm]

Did you also test with digital inputs?

I did and noted in the review that performance is the same.

 

[M.C. Logan]

Doesn't have a DAC pre-out.


Feature set is wide which could make many use cases if you want to, it doesn't have to be a desktop device only.
Just to name one, pair it with decent bookshelf/floorstands and a subwoofer on a ARC connected TV for a more than decent soundbar replacement.

Hardly, a soundbar fits under the telly, or on the wall, this requires multiple wires, additional stands/mounts and somewhere to put the amp. Completely different use case.

 

[Guddu]

Hardly, a soundbar fits under the telly, or on the wall, this requires multiple wires, additional stands/mounts and somewhere to put the amp. Completely different use case.

Okay.

 

[Guddu]

I did and noted in the review that performance is the same.

Now i found it.

BTW, your video's are missed.

 

[Matthias]

Amir says the amp got toasty during testing. If I was interested in this amp, I would scour the internet for more information on its thermal properties. Heat reduces life of electronics.

Only can share my observation with my D1 which is probably very similar from the amp stage - with the 36V Power supply I have some 7 Watts of idle comsumption and case temperature settles in at about + 10 -15°C above room temperature. With the 48V Power supply I have about 11 Watt idle and case temperature around 20 ... 22°C above room temperature so in a normal room with 22°C the case will have around 40 - 45°C. Listening to music at normal levels add some average 2 - 3 Watt power comsumption measured with an eve power plug and no significant difference in case temperature. This is also in line with a quick estimation from Claude AI that a aluminum case of this size will radiate around 5Watts with a dT of 10°C, so + 20°C is to be expected with 10 Watt losses.
The D3 probably will run a little warmer due to the extra DAC and stuff but I guess the extra power consumption will be below 5 Watt / 10°C more than the D1. Think temperatures of around 50°C are not really ciritical with all the used elcos rated around 100°C so they still will have a much longer than rated lifespan at around maybe 50 - 60°C in the case, so for normal / average music listening where peak power only is reached for fractions of a second and average power is more around 5 Watt max this is fine.
If you'd push this amp to max power for longer time it probably will get (to) hot - 2*100 Watt for prolonged time would mean another 20 - 30 Watt thermal losses = some 50°C more case temperaure - this would result in a boiling hot case of 100° C.

 

[xanalog]

Thank you for the review,

??? You can implement analog volume control using a pot and a buffer (IC or transistor). This can't be controlled using a remote unless you make it either motorized, or us a volume control IC. The former costs more money. The latter costs you SNR and distortion.

The volume-knob sure doesn't look 'motorized.

 

[somebodyelse]

(Am I the only one, that when I see HDMI ARC support, I wonder if it has direct DSD?)

I can't say whether you're the only one. I don't remember DSD being among the formats that can be negotiated over ARC.

 

[kyuu]

I don't remember DSD being among the formats that can be negotiated over ARC.

It is not, AFAIK. HDMI ARC is limited to stereo PCM and 5.1 configurations of Dolby Digital and DTS (the older, lossy versions). More than adequate for a 2.1 amp.

 

[somebodyelse]

It is not, AFAIK. HDMI ARC is limited to stereo PCM and 5.1 configurations of Dolby Digital and DTS (the older, lossy versions). More than adequate for a 2.1 amp.

That matches my recollection. Since it's essentially the same transport protocol as spdif and toslink (but over a different physical layer) they could have included DoP too, but I don't remember it being in the list of options.

 

[Svensson]

What exactly are the use cases?
ARC has no use on a desktop, where a monitor, not a TV, is in use. It's not much use for a main hi-fi (where it might get used of the ARC for those not interested in multichannel) due to minimal analogue inputs, which are equally pointless on the desktop. I simply do not get these type of devices. Active speakers are less cluttered for a desktop and WiiM/Sonos etc. more functional for entry level hifi.

I think it has a few potential uses and I wasn't even thinking of desktop use, at all. For me, it could work as an additional set up witihn the house. My daughter might like it for her room. It would have been a dream for me when I was a student in a shared house. More than enough power, small and neat either for simple stereo hifi +/- with TV connection and possible gaming etc.

 

[TurtlePaul]

Conflicted on how to feel about these lackluster PFFB amps. Yes, they are very practically usable but some manufacturers have perfected frequency response dependency and SINAD.

I feel the PFFB rankings are (grading on a curve):

A+: Purifi and Hypex
A: Topping
A-: 3e
B+: WiiM
B: Fosi
B-: Aiyima
C+: Douk/Ampapa
C: O-Noorus

I rated this as “not terrible” because 88 SINAD and being +0.9 dB at 20 khz 8 ohm due to load dependency. Stats that can be matched with no PFFB at all.

 

[Rja4000]

Doesn't have a DAC pre-out.

Then what does the following mean ?

-RCA input/output multiplexing: RCA is not set to input status, but converted to pre-amplifier output (audio source sharing mode).​

-There are four working modes:​

Decoding mode: D-F mode, D-B mode;​

Amplifier mode: A-F mode, A-B mode.​

 

[Guddu]

Then what does the following mean ?

You are right, this means RCA can be used as input or output.

 

[dcolak]

Why not add a bit more money and get an entry level amp from one of the known brands (marantz, yamaha, etc.)? You'll get a much better remote control, many inputs, nice case and might even get a phono and earphone amps.

 

[rolfrander]

Why not add a bit more money and get an entry level amp from one of the known brands (marantz, yamaha, etc.)? You'll get a much better remote control, many inputs, nice case and might even get a phono and earphone amps.

It has been a while since a cheap amp from any of the major brands was tested, but I found this from 4 years ago:

Marantz NR1510 AVR Review

This is a review and detailed measurements of Marantz NR1510 5.2 4K slim Home Theater AV Receiver. It is on kind loan from a member and costs US $799. I have been wanting to test a slim AVR for a long time as they much better fit under a TV in a living room than the monster that regular AVR...

www.audiosciencereview.com

At over three times the price and worse performance, you have to decide how much the extra inputs are worth to you.

 

[rolfrander]

It has been a while since a cheap amp from any of the major brands was tested, but I found this from 4 years ago:

Marantz NR1510 AVR Review

This is a review and detailed measurements of Marantz NR1510 5.2 4K slim Home Theater AV Receiver. It is on kind loan from a member and costs US $799. I have been wanting to test a slim AVR for a long time as they much better fit under a TV in a living room than the monster that regular AVR...

www.audiosciencereview.com

At over three times the price and worse performance, you have to decide how much the extra inputs are worth to you.

There is this one, which is very good (especially for the price), but lacking HDMI ARC (which is a requirement in many use-cases)

Yamaha A-S701 Stereo Amplifier Review

This is a review and detailed measurements of the Yamaha A-S701 stereo integrated amplifier with included DAC and Phono stage. It is on kind loan from a member and costs US $800. The A-S701 is one of the best looking amplifiers I have tested. Yes the controls are plastic unlike the glory days...

www.audiosciencereview.com

 

[Joe Smith]

Nice amount of power, high connectivity. Price a bit high compared to other options in the class, but for folks wanting to have one box that incorporates digital input, a solid choice.

 

[dguillor]

Only can share my observation with my D1 which is probably very similar from the amp stage - with the 36V Power supply I have some 7 Watts of idle comsumption and case temperature settles in at about + 10 -15°C above room temperature. With the 48V Power supply I have about 11 Watt idle and case temperature around 20 ... 22°C above room temperature so in a normal room with 22°C the case will have around 40 - 45°C. Listening to music at normal levels add some average 2 - 3 Watt power comsumption measured with an eve power plug and no significant difference in case temperature. This is also in line with a quick estimation from Claude AI that a aluminum case of this size will radiate around 5Watts with a dT of 10°C, so + 20°C is to be expected with 10 Watt losses.
The D3 probably will run a little warmer due to the extra DAC and stuff but I guess the extra power consumption will be below 5 Watt / 10°C more than the D1. Think temperatures of around 50°C are not really ciritical with all the used elcos rated around 100°C so they still will have a much longer than rated lifespan at around maybe 50 - 60°C in the case, so for normal / average music listening where peak power only is reached for fractions of a second and average power is more around 5 Watt max this is fine.
If you'd push this amp to max power for longer time it probably will get (to) hot - 2*100 Watt for prolonged time would mean another 20 - 30 Watt thermal losses = some 50°C more case temperaure - this would result in a boiling hot case of 100° C.

Thanks for the info. I have a couple of comments. Some portions of the board may be warmer. There's a variety of electrolytic capacitors on the board. All electrolytic degrade faster at higher temperatures. Some may have less margin. Without having a thermal image and data for all the capacitors, it's impossible to know how the life is affected, but I try to buy amps that run cool to minimize the issue. Cheers.

 

[Scrivs]

Depends. If the same NJM is used here as in the other O-Nooruses, it is probably true but would not seem limiting with this kind of amp performance. Some of the newer PGA chips, for example, are good for >100 dB SINAD and <-120 dB harmonics if you pay careful attention to load impedance. I just can't remember where I have seen measurements.

“O-Nooruses” These names sure are getting “creative.”
Sounds like a water/mud dwelling beast found in the bogs of Ireland