Amplifier Over-Current Condition Detected

My Uniti Atom displayed this message. whenever i turn the volume up, the stream cuts out and this message pops up. I am not doing anything differently than i have ever done. i have had the unit for a couple of years. Anyone have any idea what this means, and how it can be fixed? thanks.

Have tried anything? How about trying unplugging it for 10 minutes. Not just turning the power off.

i did try that, actually. that is usually the first thing i try! i got a better look at the message. It only flashes for a second. It says: “Amplifier over-current detected. Reduce volume and check loudspeaker connections.” So…i just checked the connections. i think they are ok. I have emailed Naim support too, so maybe they will know more. and thank you for the suggestion…much appreciated!

With the unit powered off. Unplug and replug all the speaker cables at the unit and at the speakers. And look for spider webs or any other anomalies. I’ve seen spider webs cause shorts!

Thank you. I will give that a try.

l assume it is sound level related not just vol control setting - i.e. at a given setting where it happens with music recorded at a high level or with high peaks, but not with music recorded quietly or without high peaks?

Is it possible that it has always done that on loud peaks, but you only happened to look at the screen and see it once recently, and after that you keep looking at the screen and so see it all the time?

hi, thanks for this note. I have 2 Atoms. this one, i have had for around 2.5 years. this problem just started out of the blue. One, it just kept cutting out at higher volumes. didnt matter what kind of music i was playing, or the source. i would have noticed if it happened before because of the constant cutting out. So, i am thinking a connection has come loose or dirty, or there is a hardware issue. and it happens regardless of the type of music i am playing. I listen to everything from classical to metal. Thank you for the suggestion! much appreciated.

What speakers and speaker cable are you using - and how long is the speaker cable?

It could be the speakers, cabling or both are presenting too demanding a load on the amp i.e. sucking too much current, which can be typical of low-impedance speakers and/or those which have nasty impedance curves (e.g. some say they are 4-ohmers but can dip alarmingly below this level).

In addition to what Happy Listener asks above, check for any shorts along the speaker cable path.

Then try swapping the Atoms over to see whether the same thing happens to the other unit.

right, except it has been working perfectly for more than 2 years. then, out of the blue, it just starts to happen. Very frustrating. Thank you for your help.

good idea. i am going to do my best to figure it out this weekend. thank you!

Thsi warning also repeatedly appeared on a Uniti Nova, and my dealer asked me to return the device for repalcement, presumably after consulting Naim.
My conclusion was that something was seriously amiss, and I declined to accept the offered replacement as this would have been the fourth one!
I ended up acquiring an NDX 2 and a Supernait 3 which was a lot more than I had ever planned to spend, so I guess Naim and my dealer ended up winning from the situation.

Ugh, that is depressing! thing is, my unit worked perfectly for a long time. So, its strange that it would suddenly start to happen out of the blue. Going to unplug and replug everything and hope that does the trick.

That used to happen to me with a Uniti I used to have not that exact message but something about temperature very, very annoying when you are in the middle of listening to something It never did stop so I moved it on.
I did have 4ohm speakers but had 5 meter lengths of Nac A5 and I also had a Unitiqute 2 which drove them perfectly well without issue.

so you got rid of it and replaced it? Or were you able to fix the issue, and if so, how did you do that? thanks.

It would be helpful to understand what speakers/cable is being used, as speakers also have circuit boards in them (crossovers), and both speakers/connections/terminals can change over time (e.g. even spooling up a speaker cable can have dramatic effects, as it changes capacitance of the overall circuit (IIRC)).

It’s also the case that driving ‘big’ or ‘demanding’ speakers with a relatively under-powered amp is likely to cause issues/damage, perhaps over time, than the other way round.

It could the Atom but it could be the general set-up - and more info is needed around this, if only to assist in mitigating the effects you’re experiencing.

The cables are Audio Quest type4 and are 4 feet or so long. the speakers are not big or demanding. They are B&W bookshelf speakers. This weekend, I am going to unplug and re plug the speakers. And then cross my fingers. otherwise, I will have to ship the unit back to Naim. it has been working flawlessly for 2 years. thanks for the reply.

Are your speaker cables in conventional, single wire configuration? No fancy biwiring going on, and links still in place between the 2 sets of terminals on the speakers. (I’m assuming there are two sets of terminals as most B&W speakers have them?) Naim amps generally work better with longer lenths of speaker cable in regular single wire configuration. Not normally too critical on an Atom as it could be on a separate Naim amp, but worth checking anyway.

OK & understood - but, in the world of hi-fi (and it is/was a trait of some B&W speakers), smaller size doesn’t mean easier to drive - strangely larger box speakers, although having more drive units, can be more efficient and easier to drive.

On the face of things, and I don’t think you are the first to encounter this (and there’s no guidance in the Quick Start Manual/Guide from what I can see), I suspect the combo of the speaker cable (not just type of cable but also length) & speakers isn’t an easy load for the Atom, especially where the volume is pushed a tad. Yes, it may have been OK for a long time but things do change.

I wish you well in resolving this.

FYI, have a look here to understand what Naim’s broader requirements & approach are re speaker cables/length etc,.

@Richard.Dane -

Richard, queries around speaker cabling seem to come up quite often for the Uniti-range products - and there doesn’t appear to be guidance on whether e.g. NACA5 is advocated/lengths etc, (not from the on-line QSG).

Can the Forum FAQ on this be updated, to at least give some direction on what to avoid with the Uniti range, as these products are targeted far differently than the Classic Range et al, where dealers may have more involvement?