Uniti Atom sound quality - punch and noise

Hi everyone,

I am new to forum and new to Naim.
I need an advise, 'cos maybe I have unrealistic expectations, that should be toned down.

I have Uniti Atom, which - when turned on - generates audible “punch” (a lower midtones impulse) in the speakers.
I have not noticed this with other device I have. And it is not the speakers problem, as I switched them.

Also - Atom generates quiet noise, audible when not listening to the music. It is not loud, and relatively independent from the volume set.
Whatmore I have just noticed when I turn the knob noise gets tad louder, then gets back. When I play music, it might be difficult to discern though. But I know it is there.

I would expect no “punch” and no noise from a HI-FI device. Especially from Naim, which I heard to be praised only (but of course these praises related to earlier hardware than Uniti Atom).

Or is it too much to expect from “entry level Naim device”?

Should I return Uniti Atom OR am I exaggerating?
The “punch” happens only when switching on and is not that “punchy” actually, and when music plays who would discern the noise, so why bother?

I would love to hear your opinions.

Thanks in advance,


It is normal to get a sound from the speakers when you turn it on. The answer is to leave it on all the time. You will also get a gentle hiss through the speakers. That is normal too.

So leave it switched on, settle back and enjoy the music.

I get neither punch nor noise from my Atom.

I know that more powerful amps can have a punch or thump when switched on, I think that’s normal.

What’s the sound quality like when playing music?

Maybe the noise is connected to the proximity to other electrical devices, or speakers? Have you tried different locations? Also what is it plugged into? It is a multi-socket adaptor shared with other devices, or straight into the mains?

I would suggest experimenting with location and moving other electrical devices.

If the noise is a problem I would suggest going to see your dealer to see if it is replicated there.

Good luck, it’s a great piece of kit.

I’m sure it depends a bit on speakers too.

I get a fairly firm “thud” from turning on my lower powered Uniti Qute2. I’ve never known a Naim amp to not do it to some degree.

As HH correctly says, leave it on 24/7 for best performance anyway.

My nova only gives a very quiet pop when coming on

I suspect that the OP’s first language is not English. Assuming punch and noise mean switch-on thud and gentle hiss, it’s not a problem.

My Nova also produce a pop and nobody will tell you what it is. And it isn’t normal. After the FW update it seems to be more a quiet pop.

Hi everyone,
thank you very much for your replies! They are very interesting.

Let me start from the basics.

  1. @hungryhalibut: you are right English is not my first language. Thanks for expanding my vocabulary. I guess it is much more precise to say about “thud” and “hiss”. So let me reformulate.
  • I hear switch-on thud from my Uniti Atom powering Monitor Audio Silver 100 (directly, without any amp in between). I hear hiss when no music plays.

  • SQ wise I like it a lot, what Atom and MA deliver. I am really delighted, with the exception of this hiss.

  1. I made some tests (though not all yet. Thanks @back_in_the_game for your ideas. For example I did not think at all about going straight to the mains. I will try it, but please see point 5 below.

  2. I have compared it to other setup I have (CXN, CXA80 + Monitor Audio Silver 8). I do not hear switch-on thud. I did not ever noticed any hiss, but for testing purposes I cranked the volume all way up, and some hiss appeared actually. This is not discernible though under my standard listening conditions (as opposed to Atom).

  3. turning Uniti Atom knob there and back (so no actual change of volume) generates some additional hissing, as if turning (friction? mechanics of the move) impacted this noice, for a moment only. No one has commented on this point. I suppose no one experienced it. This is a minor point, but a part of slightly longer story (please see 6.)

  4. I have moved Atom to different room, attached it to different speakers - Monitor Audio Silver 8. So this should eliminate impact of neighbouring electromagnetic fields, if any. The same thud and hiss can be heard, so this is NOT the speaker related phenomena.

  5. Why am I so concerned? This is my 3rd Atom in 6 months or so.
    a) The first could not start up properly nor connect to the remote controller, so I returned it.
    b) 2nd produced thud and hiss, which after some time got so prominent, that I returned device for the repair. It took Naim Service 3 months (or even longer! When I got it back, not only was the prominent hiss there, the display did not work anymore. I returned it and requested a new device.
    c) This is the one I have, and these are the experiences I have with the 3rd one. I started wandering if there is a certain faulted series or any other kind of problem.

I got mixed responses from you, but generally to sum your voices up:
a) switch-on thud (or pop) is acceptable to you
b) the hiss/noise

  • I see only an opinion of @hungryhalibut, who seems to experience it as well, but does not bother (am I right @hungryhalibut? Do you get it from your Uniti Atom? At what volume levels can you hear it?)
  • noone else had anything like that, right?

Any comments on this? The hiss? The troubles you had (or you heard of) with Uniti Atom reliability?

thanks and cheers,


Hi Stan

I have owned Naim since 1983 and they all hiss a little, which is why I say it’s normal. Now I am 58 I don’t hear the hiss anyway!!

If it sounds fine I really wouldn’t worry.

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Well I’m 48 so I guess this is something to look forward too.

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I have owned various Naim amps and all-in-one boxes, including a Superuniti, a 200 and a 250. All of them produced a hiss from the speakers, but never loud enough for me to consider it a problem. All of them made a thud when switched on or off. Quite audible, but not so alarming when you are expecting it, and harmless. I now own an Atom as well, and with this I hear no hiss at all, and any turn-on thud is so feint I never notice it at all. So if yours is loud, I wonder if either your Atom, or perhaps your mains supply, has a problem.

The hiss can be more audible on different speakers. I never really noticed it until I switched speakers that are more sensitive than the old ones and have a different tweeter tech. Likely the MA as they tend to use metallic based tweeters which tend to be brighter are showing it up more.

Hi Stan,

My ‘switch on thud’ is barely noticeable, but years ago when I had Linn Isobariks and a bigger amp, there was a loud thud when the amp was switched on - at the time I thought it a reassuring thud! I would agree that this is not something to worry about unless you think that it is sufficient to damage your speakers.

I used to own a secondhand, and rather old, Naim 12s pre-amp and that hissed VERY loudly; I put up with it as it was cheap, old and the sound quality was amazing - but a new Atom should not make a loud hiss at normal sound levels and I would suggest getting the dealer’s opinion and/or a listen to his demo unit under the same conditions.

I am really concerned by all the problems you (and others) have had, I am lucky to have avoided them but I am seriously worried what is going on generally and to understand if it is only Uniti models as I am planning to upgrade at some point.

At least your unit sounds great when playing music, maybe you could turn a blind eye (ear) to the hissing?

Best of luck, as it seems that is what is required.

if you are very close to your speakers, with normal volume level , you can hear a little hiss. But not from your listening position.
With some tube amps, yes. But not transistor.
I may be wrong but i feel it’s not normal. You should ask your dealer.
Test the atom on other speakers and your speakers with an different amp.

The plop as i call it, used to be very loud, but Naim have managed to bring it to a soft plup sound, it is normal when coming in and out of standby.

Thank Hungryhalibut for all this:).

I must admit - sound is good, I love it a lot.
Just was looking forward to telltale signs of next forced exchange :confused: If I have to replace Atom, I prefer to make it period of warranty/guarantee.

Thanks for your opinions!



What you write about tweeter tech sounds reasonable.

I have done a comparison on different speakers (though MA as well), but also auditioning another amplifier. Conclusion of this double test was:

  • there is a hiss on both of the speaker pairs I have
  • Atom hiss was audible earlier (= at lower volume setting).

But if this is normal to majority, and if it is not a sign of misproduction, I could live with it.

Thanks for your answer!

Hi Tony,

now that I know “switch on thud” is a feature, and not a bug, I do not bother any longer.
Ha! Reassuring thud - that’s a great proof that interpretation is in our heads :slight_smile: (if only it depended on us fully").

My Atom’s (I mean this piece, 3rd one) hiss is not loud. Probably I would assume - like hungryhalibut was suggesting - that it should be so, and would not bother. BUT… with my history with Naim Atom I was in doubt.

So thank you for the mailings and reassuring thoughts!

As for the blind ear :wink: - yes, my Atom sounds really great, I enjoy it a lot and will definitely turn blind ears to the hissing. Anyway, still 10+ years more I am expect not to hear it neither ;).

I have learned from my dealer, here in Poland, that Naim is merging with Focal. I am not sure if this was regarding the vendors themselves or just their distributors. If though these are vendors merging, then - maybe - the alleged quality issues were related to merge & acquisition challenges, and would subside afterwards?

Whatever the reason - all the best to you as well, especially with your upcoming upgrade.

Big thanks,

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I had 2 Atoms. All of them had hiss and turn on “thud”. I asked Naim support about these problems. The answer was: “The hiss and thud is perfectly normal and nothing to worry about, it is a consequence of the amplifier design strategy.”

My speakers are Focal Aria 926.