Connecting a Headphone Amp to Uniti Atom

Please forgive the novice question (I can talk all day about artists/music but am still a bit of a hifi virgin).

I am considering buying a headphone amp for use with my Uniti Atom and Sennheiser HD 660s headphones. The connections will likely be analogue so do I connect the RCA leads into the analogue pre outs on the back of the Atom?

Secondly, will this mute the speakers? Told you it was terribly basic.

Many thanks


What’s wrong with the headphone amp on the Atom?

The analogue outs are to go to a power amplifier not another pre so you’ll have competing volume controls, and no it does not mute the Atoms output. Just use the Atoms headphone output or use a different input to your headamp. Personally I am not a fan on Naims headphone outs at all and don’t use my Atoms at all. I built another rig for headphone listening which is much better.

Pretty dull in my experience and not good at driving my Focals at all.

Many thanks for your reply CG. I’m glad I asked the question before I bought anything but my knowledge is quite lacking in this area. I assumed that I could use the Atom as my source and hook up a headphone amp to it, via the RCA.

How do people normally connect a headphone amp to their hifi? - or is it better to use a separate arrangement such as your Rasberry Pi/DAC/Amp?

I told you I was confused!!

Depends on the system.

I myself use a Pi4 to my DAC in my bedroom setup with my SMSL SU 9 which feeds my Schiit Magni Heresy Amp. It’s great I added an Ifi iPurifier USB in-between and it made a subtle improvement.

Downstairs I use my Roon core which is a fanless Linux based PC, again via an Ifi iPurifier 3 into my RME ADI-2 DAC Headamp. This sounds sublime with my Focal Elears. Again I thought the iPurifier made a small improvement. Although I am not sure they are really necessary and likely placebo.

Others with Naim streamers often feed out from the streamer into their DAC digitally or feed of its line out and use DIN to their main systems. Or they use the inbuilt headphone output of the amp.

Both mine have far more weight and are more natural and neutral than the Atoms headphone amp and can power most headphones with no issues. Naims headstages are a little under whelming and under power.

You would normally connect a headphone amp using either a line out from a source or via a rec out via a tape loop on a pre-amp.

The difficulty here is that the Atom is a compact all-in-one and has neither a rec out or a line out. I guess the feeling is that being an all-in-one with a headphone amp onboard, this would likely not be needed. However, all is not lost as there is a pre-out. Only thing is, this is not a fixed output like a line out, it instead is variable output controlled by the pre-stage volume control. That means if you add a headphone amp the signal will be going through two volume controls, which takes some juggling and there may well be some performance loss.

The difficulty is that you can use the pre-amp out into a headphone amp, but you can’t disable the signal going to the speakers, leaving you with having to unplug the speakers when using the headphones on their own. For my media room, I have the Nova on speaker duties and run a second Heed Audio DAC and headphone amp setup with second runs from the sources to both the Nova and the DAC. Then I just switch the Nova to an un-used source when using headphones. It’s a bit off a faff - my old Uniti2 has line and pre out and you can disable the speakers (well, I could but the screen has died so it’s more difficult now…).

On my NDX2/SN2 setup, I just run a Heed headphone amp of the NDX2 RCA output, which is much simpler.


What rig is that?

Ignore that, just seen your post.

Thanks so much @CrystalGipsy, @Richard.Dane and @Mike_S for your interesting and knowledgeable feedback.

I have a better understanding about the connections required and have been doing some further research based on your replies. I am currently using the Atom’s headphone output and it sounds fine so I will continue to use it but I am interested in exploring how a dedicated headphone amp would sound.

I also own a Zen Mini Mk 3 and I use it very effectively as a Roon core and it seems to have an RCA analogue output (as well as USB ones) and an onboard DAC. From reading some reviews, it seems that I could connect a headphone amp successfully to this or a separate external DAC/Amp as well so it does appear that I have some options which I will explore.

Any further comments/advice would be most welcome, thanks so much for all the input so far.

Who said Hifi is an expensive and addictive hobby!! :joy:

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I’ve said it before but the lack of a line out on the Atom as well as most other Uniti products (UQ2, SU) is a very surprising omission. In that context the inclusion of the digital out on the SU and UQ2 was slightly more puzzling.

I had the same problem with the old Uniti range. They struggle to drive high impedance cans convincingly. Sadly, there isn’t really a good solution other than put up with it or downgrade your headphones. The Uniti range will actually sound better on lesser cans that present less of a challenge and are less revealing. Something 150 Ohms or less, ideally under 100,

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Many thanks @el_soldado and @feeling_zen for your observations.

It seems that many pieces of Hifi these days come packed with features and connectivity so I don’t know if a line out or similar outputs impact on the effectiveness of these units but I do take @Richard.Dane’s point about the compact all-in-one, however (isn’t there always a “however”!) if one adds analogue and digital inputs to a unit, as is the case with the Unitis, then the implication is that you are offering the consumer the option of adding additional boxes - I have actually attached a CD transport and a Rega P3 turntable.

Whatever about the Atom, I would have thought the Star and most certainly the Nova, given their prices, would have extra outputs but perhaps it’s a trade off between features and effectiveness/performance - what do I know :joy:. What I DO know is that I DO love my Atom!!

As mentioned above, it seems that I have some options with my Zen Mini so all is not lost.


I have been using my Nova headphone jack to drive LCD4’s and it so far has been a fantastic experience.

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