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Naim Uniti Atom Review (Streamer & Amp)

Rate this streamer:

  • 1. Poor (headless panther)

    Votes: 260 70.5%
  • 2. Not terrible (postman panther)

    Votes: 85 23.0%
  • 3. Fine (happy panther

    Votes: 15 4.1%
  • 4. Great (golfing panther)

    Votes: 9 2.4%

  • Total voters
    369

amirm

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This is a review and detailed measurements of the Naim Uniti Atom streamer, DAC and integrated amplifier. It is on kind loan from a member and costs US $3,799.
Naim Unity Atom Review integrated digital analog streamer amplifier.jpg


The overall industry design is attractive and has a high-end look to it. Alas, every part of the unit has an ultra sharp edge from heatsinks to edges of the plexiglass (?) front panel. It is a heavy box which makes you really feel those sharp edges as if they are going to tear into your skin. It was unpleasant every time I had to move or rotate the unit.

The front panel is large and sharp which I like. Alas, and strangely so, it is not a touch screen. In this day and age and at this price, a touchscreen is a requirement in my opinion. A very large rotary control managed the volume. It seem to have some kind of acceleration but wasn't very intuitive.

Here is the back panel:
Naim Unity Atom Review integrated digital analog back panel ethernet HDMI streamer amplifier.jpg


I was surprised to see the compact binding posts that are made only for banana plugs. Likewise there is no USB B to use the unit as a DAC. Maybe you can use the type-A connector for that but even so, it is very unusual choice. Nice to see a floating ground switch. In my testing, it only impacted the networked tests. Otherwise it had no effect.

Inclusion of HDMI is very important to allow sound from TV to be piped into it.

Upon booting and with Ethernet cable plugged in, it nicely told me there is new firmware. It took something like 10 minutes to download the image and then went into a seemingly infinity cycles of booting, dark screen, non-descript progress bar and power button that would fade on or off or solid on. I left there for probably half hour when it finally seem to be ready.

There is the usual app to control it but I opted for the included remote control. It too has very sharp edges but otherwise functional.

Naim Uniti Atom DAC Measurements
I started by testing the unit using Coax due to lack of type-B or type-c USB port. Here is our usual dashboard:
Naim Unity Atom Measurements DAC streamer amplifier.png


Distortion dominates causing our SINAD (noise+distortion) to barely reach into "fair" category:
Best streamer dac review 2022.png


Distortion rises into the noise floor of even 16 bit content so not a good first showing. As noted, changing the grounding mode made no difference in any of these measurements.

The output stage is capable of higher voltage which is nice:

Naim Unity Atom Measurements DAC THD vs level streamer amplifier.png


Good to see the output does not become all distorted once the internal amplifier is pushed beyond clipping.

Noise performance is not competitive with even budget DACs but almost good enough for 16-bit playback:
Naim Unity Atom Measurements DAC dynamic range streamer amplifier.png


Multitone distortion was quite high:
Naim Unity Atom Measurements DAC Multitone streamer amplifier.png


Jitter display looks clean but noise floor is high and is masking interference patterns:
Naim Unity Atom Measurements DAC Jitter streamer amplifier.png


Levels of those spurious tones though is quite low and inaudible (-128 dB).

We have a rather odd filter response:
Naim Unity Atom Measurements DAC Filter streamer amplifier.png


This partially contributes to rather poor noise+distortion relative to frequency:
Naim Unity Atom Measurements DAC THD vs Frequency streamer amplifier.png


Finally, linearity matches the fair performance of the rest of the system:
Naim Unity Atom Measurements DAC Linearity streamer amplifier.png


Naim Uniti Atom Amplifier Measurement
Given the choice of analog or digital input, I tested both which producing 5 watts:
Naim Unity Atom Measurements Digital In streamer amplifier.png


Naim Unity Atom Measurements Analog In streamer amplifier.png


Performance is very close so I opted to use analog in as that makes the comparison to other amps easier. Notice the high power supply noise at 120 Hz (double mains frequency in US). Overall ranking is well below average:
best streamer amplifier review.png


Frequency response test with analog input shows a brick wall filter which indicates input is being digitized:
Naim Unity Atom Measurements Frequency Response  Analog In streamer amplifier.png


Shame then that no DSP functionality is provided. The roll off filter in the ADC causes some drooping in the high frequencies.

Crosstalk response was kind of shaky but overall good:
Naim Unity Atom Measurements Crosstalk Analog In streamer amplifier.png


Multitone test once again shows less than optimal performance:
Naim Unity Atom Measurements Multitone Analog In streamer amplifier.png


Rated power is low and that is what we see:
Naim Unity Atom Measurements Power 8 ohm Analog In streamer amplifier.png



Naim Unity Atom Measurements Power 4 ohm Analog In streamer amplifier.png


Naim Unity Atom Measurements Max and Peak Power 4 ohm Analog In streamer amplifier.png


Sweeping the frequency for power measurement we get orderly response:

Naim Unity Atom Measurements Power 4 ohm vs frequency Analog In streamer amplifier.png


Notice the typical sharp drop in power at 20 Hz. This is why you need more powerful amplifier than you think you are getting. Power is needed in bass but the reservoir capacitors in the power supply get depleted and you don't get as much output.

Naim Unit Headphone Amplifier Measurements
I expected the headphone output to be "junk" but it actually is not:

Naim Unity Atom Measurements Headphone 300 ohm Analog In streamer amplifier.png


That is plenty of output for satisfactory response of high impedance headphones. Noise floor is not competitive with any modern/recommended headphone amp but could have been far worse. At 32 ohm though, available power is much more limited:
Naim Unity Atom Measurements Headphone 32 ohm Analog In streamer amplifier.png


Sweeping the load we see that the headphone amplifier is not capable of much current delivery:
Naim Unity Atom Measurements Headphone Power vs impedance Analog In streamer amplifier.png


So best to stay with high impedance headphones.

Naim Uniti Atom Streaming Measurements
I ran the streaming tests a day later and here, I noticed noise bleeding into the output:
Naim Unity Atom Measurements DAC Roon Grounded streamer amplifier.png


So I tried the ground lift switch and it remedied that:
Naim Unity Atom Measurements DAC Roon Floating Ground streamer amplifier.png


SINAD though is dominated by high distortion so didn't matter one way or the other. And performance is the same as local/coax S/PDIF input.


Conclusions
Performance of Naim Atom ranges from fair/adequate to rather poor. Shame that when you pay so much for a piece of audio, not much design hygiene is included. I suspect more went into software development and enclosure design than making sure the hardware is performant. I hope for a version 2 the company works to substantially improve the performance of these subsystems. I am sure many buy a Naim product thinking they are getting great audio performance.

I can't recommend the Naim Uniti Atom streaming amplifier.

P.S. I was going to give the mailman panther rating to the unit but he is out making deliveries......

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PatentLawyer

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Good grief. There is so much sub-par equipment lurking out there.
 

peniku8

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Industry standard reading for power figures is at 1%THD, which is at -40dB on the graph. Why make it seem like the amp can't match its specs when it actually exceeds it by over 10%?
It's fair to reason that distortion takes over at ~36W, but industry norms are industry norms and I think the text on the image is rather misleading.
 

sarumbear

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Another brand I was in love with, rubbish.
Since my friend Julian passed away, Naim has lost the plot. Shame as they had a decent R&D department until they were sold to the French.
 
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amirm

amirm

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Industry standard reading for power figures is at 1%THD, which is at -40dB on the graph. Why make it seem like the amp can't match its specs when it actually exceeds it by over 10%?
Nobody reasonable reading that graph indicates it is not meeting its spec. Unlike many other companies, NAIM does not specify power at 4 ohm so I could not show it with 1% distortion test I run. And no, there is no such "standard." Companies spec power at all kinds of metrics and there is no telling how they even measure THD at 1%.
 

Doodski

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Industry standard reading for power figures is at 1%THD, which is at -40dB on the graph. Why make it seem like the amp can't match its specs when it actually exceeds it by over 10%?
It's fair to reason that distortion takes over at ~36W, but industry norms are industry norms and I think the text on the image is rather misleading.
Test here are measured at the knee as far as I know.
 

MZKM

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Industry standard reading for power figures is at 1%THD, which is at -40dB on the graph. Why make it seem like the amp can't match its specs when it actually exceeds it by over 10%?
It's fair to reason that distortion takes over at ~36W, but industry norms are industry norms and I think the text on the image is rather misleading.
Company does not specify THD or frequency. Blame companies not giving detailed specs.

If you look closely though, the other channel does meet 40Hz. So, do you report the worse one or the average?
 

sarumbear

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index.php


Industry standard reading for power figures is at 1%THD, which is at -40dB on the graph. Why make it seem like the amp can't match its specs when it actually exceeds it by over 10%?
It's fair to reason that distortion takes over at ~36W, but industry norms are industry norms and I think the text on the image is rather misleading.
What norms are they and why should we care about such high distortion?
 

sarumbear

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In short, it’s a disaster from the company.

Naim was formed back in 1973 by a good friend of mine. Julian Vereker had a tiny shop on a tiny side street in a tiny English town where I used to live. He remortgaged his house to buy a Precision Instrument system so that he can be sure his amplifiers performed as SOTA.

He is turning in his grave.
 
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peniku8

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Nobody reasonable reading that graph indicates it is not meeting its spec. Unlike many other companies, NAIM does not specify power at 4 ohm so I could not show it with 1% distortion test I run. And no, there is no such "standard." Companies spec power at all kinds of metrics and there is no telling how they even measure THD at 1%.
Stating a power measurement, followed by "higher figure X company spec" in brackets will have anyone who doesn't frequent the site assume that the company is lying about their amplifier specs.
It's a fair point that the company didn't state the THD value at the given power, I assumed they'd measure it like basically every other amplifier manufacturer does (that's why I called it a standard, because manufacturers seemed to have agreed on doing it this way, even if it's not official). I went to look for a product manual to see if I could find a more detailed spec sheet. Turns out there is no manual for this product, that's terrible!
 

dougi

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A$6000 in my neck of the woods. I'll stick with my Yamaha WXA-50 I think, at about 1/10th of the price, in this product category!
 

RandomEar

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Certainly not a good showing. I can accept that a "do it all" device isn't top notch in every aspect - being about average and very versatile would have been fine. But this is pretty bad. Luckily I'm not the target group for such a device.

What bothers me the most is that the damn DAC actually has significantly higher distortion in the multitone test than the amp! That's just sooo unnecessary. Why fuck up the easy part? WHY?!
 

phoenixdogfan

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Completely mystified why anyone would buy this at even one third its current price. The amp is low power, streamers are a commodity and can be cheaply had, and ditto dacs. And for it to have these kind of performance numbers and look so clunky to boot with no nifty color display to show the album cover, sample rate, etc. What the hell!

Just no excuse for any contemporary product to be so far off point, let alone one developed by an old, established high end house like Naim.
 
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