Naim Uniti Atom Review (Streamer & Amp)

[sarumbear]

My personal opinion was older Naim was beatifully constructed in the traditional 'belts and braces' UK school of design, but poorly performing, fragile and prone to failure, due to inadequate cooling, poor component choices and simpy overpriced by the time it arrived down under.

I wish we had the data to support those opinions or beliefs as they just that.

However, I agree that NAP250 had inadequate cooling but it was not fragile. It simply cut off if heated. You would be hard pushed to over heat it in a normal domestic use. I never managed mine. If you needed a professional amplifier or had a none-domestic use case then you would buy the NAP135, which was mono and had a fan. Horses for courses…

Can you elaborate on your “poor component choices” comment please?

Finally, early Naim power amplifiers were based on a sample design from the RCA manual for the 409xx series transistors. The only difference is the delay on the protection feedback and regulated power supply. Especially the latter was the main reason the amplifier sounded louder than most because when clipped there was no double mains frequency modulating the audio.

 

[Tangband]

I have no interest in the brand now, except to marvel at the annual price increases... I've spent time with the Statement amps and wouild say they're more powerful (they appear unburstable subjectively) than the humbler moderls, but there's still this brightly lit quality I can't fathom or test for. Into Dynaudio Confidence 60's I got a headache after forty minutes. The same speakers/room with the Chord top power amps and pre/Dave were much more benign to me.

Here's one dreadful scan I've just done of the 250. The 135's are worse and once I've sorted the PC the scanner is attached to, I'll post that and leave it be. Stereophile have had a go at one or two of the new boxes and the performance is in fairness a bit better.

View attachment 214586

Interesting .
This shows that the measurement results wasnt that good in the beginning and at that time, with vinyl records as main source with a much worse SINAD , it was ”good enough”. The NAP 250 could give a lot of current and could drive the Linn isobarik loudspeaker, while other amplifiers hade a hard time.

Maybe they are still using about the same circuits and the same topology ?

 

[sarumbear]

I have no interest in the brand now, except to marvel at the annual price increases... I've spent time with the Statement amps and wouild say they're more powerful (they appear unburstable subjectively) than the humbler moderls, but there's still this brightly lit quality I can't fathom or test for. Into Dynaudio Confidence 60's I got a headache after forty minutes. The same speakers/room with the Chord top power amps and pre/Dave were much more benign to me.

Here's one dreadful scan I've just done of the 250. The 135's are worse and once I've sorted the PC the scanner is attached to, I'll post that and leave it be. Stereophile have had a go at one or two of the new boxes and the performance is in fairness a bit better.

View attachment 214586

What other amplifier tested better, which was on the market around the review date? Unless you come to a decision by comparing these results with amplifiers from half a century later…

Also, you do realise that the test includes the preamp in the signal chain. Have you seen many tests done that way?

 

[DSJR]

Backwards [edited] caps in the power amp circuit I was told (apparently a casualty done long before JV appropriated the circuit and something to do with the introduction of PNP transistors (this info is second hand from an experienced electronics designer who knew the donor RCA circuit very well I gather and the main reason they used to go off after a few years as the caps received a back voltage which shortened their effective life over time). This may well have been sorted out now as the post 2000 cosmetic models don't seem to need as much attention over time. I need to find the email where he explained it a bit better - his own amps always performed well (AVI) and didn't really have a 'sound' at all, as well as running cool.

We REGULARLY shut our dem CB 250 down on Saturday afternoons in the store. 'Slave to the Rhythm' album (original full issue) full blast (from LP12/ittok/Karma or Troika vinyl of course) and into 3 ohm Saras, we had to turn the amp on its side to help it ventilate as the bottom got VERY hot! A client with TDL Studio 1M's had his 250 overheat a few times and he complained, to be told he'd be better with two 180's (unregulated) in bi-amp mode, which he did and his issue went away.

 

[Cote Dazur]

Was the hype/reputation based on fact, folklore or simply good marketing?

No, it was based on people going to stores where they could sit, listen and compare, yes I know, shameless times.
Now we have people criticizing who have never even heard the product perform in any way shape or form, based on looking at some test results, glorious times.

 

[sarumbear]

I have no interest in the brand now, except to marvel at the annual price increases... I've spent time with the Statement amps and wouild say they're more powerful (they appear unburstable subjectively) than the humbler moderls, but there's still this brightly lit quality I can't fathom or test for. Into Dynaudio Confidence 60's I got a headache after forty minutes. The same speakers/room with the Chord top power amps and pre/Dave were much more benign to me.

Here's one dreadful scan I've just done of the 250. The 135's are worse and once I've sorted the PC the scanner is attached to, I'll post that and leave it be. Stereophile have had a go at one or two of the new boxes and the performance is in fairness a bit better.

View attachment 214586

Am I correct to say that calculated SINAD will be around 80dB? In which case this almost a half century old pre-power combination was measured “as poor as” a modern AVR.

 

[DSJR]

What other amplifier tested better, which was on the market around the review date? Unless you come to a decision by comparing these results with amplifiers from half a century later…

Also, you do realise that the test includes the preamp in the signal chain. Have you seen many tests done that way?

All the integrated amps had a line input stage too. Naim power amps were never knowingly sold with anything other than one of their preamps (band limited to prevent slew rate limiting according to the leaflet they once produced). I'm trying to improve the scanner working, but can't scan loads of reviews. I'll try to find a good cyrus 2 one and maybe see how the HK645 (masses of currentl here) performs. there was also a powerful Tannoy amp (formerly Tresham which you may remember) and the NAD 2200 which did pretty well here was just coming around at this time. ALL of them 'sounded different' to a Naim CB model and therefore all of them were worse in our eyes. I shan't go into the seismic catastrophe when Linn introduced the LK1 and 2 amp system (sounded like a Quad with balls with 4 ohm drive capability but didn't perform that well initially and wasn't hugely better it seems when it was replaced with the Kairn/Klout in the early 90's) - but now I really am digressing - sorry...

 

[sarumbear]

Backwards electrolytic caps in the power amp circuit I was told (apparently a casualty done long before JV appropriated the circuit and something to do with the introduction of PNP transistors (this info is second hand from an experienced electronics designer who knew the donor RCA circuit very well I gather and the main reason they used to go off after a few years as th ecaps received a back voltage which shortened their effective life over time). This may well have been sorted out now as the post 2000 cosmetic models don't seem to need as much attention over time. I need to find the email where he explained it a bit better - his own amps always performed well (AVI) and didn't really have a 'sound' at all, as well as running cool.

NAP250 was always quasi-complimentary and the only electrolytic capacitors on the amplifier board were tantaluim. See below

We REGULARLY shut our dem CB 250 down on Saturday afternoons in the store. 'Slave to the Rhythm' album (original full issue) full blast (from LP12/ittok/Karma or Troika vinyl of course) and into 3 ohm Saras, we had to turn the amp on its side to help it ventilate as the bottom got VERY hot! A client with TDL Studio 1M's had his 250 overheat a few times and he complained, to be told he'd be better with two 180's (unregulated) in bi-amp mode, which he did and his issue went away.

You have just explained that you have a non-domestic use case

 

[peniku8]

Whether NAIM is delivering to spec or not the issue here. The amplifier is below par compared to a very large number of amplifiers tested. There can be no arguing about that.

That is the issue and the shame of the manufacturer.

You seem to have a lot of discussions going on here, I think you meant to reply to someone else or are mixing up conversations.
The amp is trash, I agree. Huge waste of money, that price tag is a joke.

*my* original point was that I'd like Amir to include 1% THD figures in his power plots, because that's a more common reference from manufacturers than "at the knee". That got nothing to do with this particular unit, I just happened to bring it up in this thread.

 

[DSJR]

No, the client who had TDL Studio 1M's was real and it did happen! I stated facts as I experienced them - and the 250 could run hot when used enthusiastically - we just overheated ours..

Here's the 135 test -

And the then new Krell KSA 50

I do have more, but we've drifted this off already into now ridiculous antique but still valuable and sought after products.

There was a CJ pair tested in this issue which was 'recommended' but the performance was dire - in the -30's to -40's so basically audible colourations. I can go on (later issues have the Tannoy, NAD and mk2 Krells, but not for this thread.

To compare this review Atom with its contemporay Naims, I think Stereophile has one or two tested...

 

[voodooless]

No, it was based on people going to stores where they could sit, listen and compare, yes I know, shameless times.

How is that not hype, folklore and marketing? We all know that uncontrolled listening is mostly nonsense. Store have one goal: sell you stuff. Magazine and review sites have one goal: sell advertisements. None of them have the goal of really telling you what is what.

Now we have people criticizing who have never even heard the product perform in any way shape or form, based on looking at some test results, glorious times.

Indeed glorious that this nefarious industry get exposed for what it is!

 

[sarumbear]

You seem to have a lot of discussions going on here, I think you meant to reply to someone else or are mixing up conversations.
The amp is trash, I agree. Huge waste of money, that price tag is a joke.

*my* original point was that I'd like Amir to include 1% THD figures in his power plots, because that's a more common reference from manufacturers than "at the knee". That got nothing to do with this particular unit, I just happened to bring it up in this thread.

I was replying to you but obviously I wasn’t clear. What I meant to say, and you seem to agree, the amplifier is so bad that it doesn’t matter if it meets manufacturers specs. Shit will be shit even if it was labelled as such.

 

[Tks]

Ah yes, the classic botique audiophile company move that can't clear CD quality..

 

[Cote Dazur]

mostly nonsense

You got that part right.
We were grateful to have stores dedicated to our hobby and store owners passionate about our hobby, where we could spend hours listening, I know using our ears, radical idea, bringing our own stuff to compare.
So many people lost at sea here, self congratulating on some tone test result. But you got it, yes, mostly no sense.

 

[DSJR]

You got that part right.
We were grateful to have stores dedicated to our hobby and store owners passionate about our hobby, where we could spend hours listening, I know using our ears, radical idea, bringing our own stuff to compare.
So many people lost at sea here, self congratulating on some tone test result. But you got it, yes, mostly no sense.

I'm blissful now, as I know my ears are variable and total crap without 'assistance' I'mnow thoroughly enjoying the music again without worrying any more, the system once again becoming the tool to help me enjoy the music recordings as well as 'the radio' speech broadcasts on BBC Radio 4. Hours listening in a store with little or no intention to buy is actually wasting the staff's time (I grew to realise almost too late that time is money and if the person having the dem is there to indulge himself and discuss the hobby only (almost always a him), then that's basically a no-sale and most of these enthusiast dealers failed many years ago by spending hours basically doing eff-all, sharing the love but not actually making a living - I speak with very hard earned memories here, believe me). In my older years, I now realise that digital sources and amplifiers should be a done deal with no 'sound quality' of their own to speak of (if my 50 year old Crowns can do it, then what came in between in the 'flat earth' fraternity was a major negative distraction in hobby-self-delusion as few of these systems ever really sounded much cop, especially on string tone or acoustic music). Some enthusiasts find these good performing amps boring because there's nothing to discuss (the 'Choice reviews of good measuring products gave Martin Colloms little to comment on and so many were passed over for recommendation), but then, they're talking about the gear all the time and it's usually artifice and which artifice you prefer using your ears as the guide with absolutely no objective backup. I think many here like me have been through the mill over many years and have come out this end perhaps rather jaded, looking at over-priced under-achievers for sale in the remaining audio 'salons' and now recognise the dealer ignorance and bullsh*t they spout after years of non-education (I hope I lifted out of this pool of ignorance and self-delusion, but it took a while).

The product reviewed here is a general purpose lifestyle item which helps keep remaining dealers alive in general cash-flow terms, along with the other streaming products they make. It also keeps the brand vibe going and less positive reviews like this one will probably not dent it's sales curve I suspect.

 

[CapMan]

Thanks for the review Amit. Sad to see such an indifferent product from Naim and even more sad that the subject reviews are so glowing.

And appreciate what this whole forum is trying to achieve - I feel pretty liberated with my plain ole cables - nothing above $30

 

[Tangband]

Here is two pictures of two fully regulated amplifiers . Naim nap 250 and Aiyima a07 with external regulated power supply. Most class A/B amplifiers are not fully regulated.

Is this a reason they sound good ?

 

[sarumbear]

Here is two pictures of two fully regulated amplifiers . Most class A/B amplifiers are not fully regulated.
View attachment 214606View attachment 214608

Is this a reason they sound good ?

Regulated DC supply means there’s no 100/120Hz ripple modulation on the speaker output when the amplifier is saturated. That is certainly one reason for clearer sound.

 

[contium]

Uniti Atom has the holy grail of features for me. Both Roon and Chromecast built in. That is very rare unfortunately.

 

[Loooop]

Uniti Atom has the holy grail of features for me. Both Roon and Chromecast built in. That is very rare unfortunately.

Cambridge Audio Evo has both.