I just received a 222 from a reputable dealer in Germany - It was a returned unit but guaranteed perfect condition etc.
Inside was a repair report from the Naim service department:
"Description of the device malfunction: The device makes a clicking noise when it is put into sleep mode using the app or remote control (after music has been played beforehand)
Description of the repair (translation from German): The clicking noise is a characteristic feature of all NSC222 devices. This is directly related to the design of the power switching system and the volume control system. The preamplifier is activated by two relays built into the power system, so that a significant load on the 230 V network is avoided. A soft start system is also integrated. This noise can be heard every time the device is switched on and off.
The device also includes 42 volume control relays and a circuit that controls the function of the aforementioned relays. This circuit is similar in concept to the best preamplifier, the NAC S1. Relays are also integrated, which fulfill the function of switching inputs and outputs (RCA or XLR or RCA+XLR). The preamplifier system also includes relays that prevent interference in the speakers when switching signal sources. It should be noted that the seller must have knowledge of how the NSC222 works.
Our service center has not found any defects in the device."
Upon plugging in the 222 and switching on, I immediately noticed a electrical hum - a little louder than my fridge with the compressor running. I measured on my phone with a db meter (probably not too accurate, but all I have) normal background noise was ~22db and with the unit power on ~30db. Basically enough that anyone walks in the room and would say…"what is that noise?'.
I have tried turnning off all other electrical equipment near, using the same socket and cable as my Atom uses (Atom has zero hum). No improvement.
Then I tried to put the unit into standby…oh boy.
I am used to to click and clunks of the Atom and was expecting the same. The 222 unit powers off the (presumably) main power supply (an audible relief from the hum). A few second later power supply is switched on again. The screen is still off, so looks to be in standby and the App confirmed its in standby, yet the main power supply is back on and humming. Then click clunk, off. Repeat. This happens minimum 5 times, and once I had to disconnect the mains cable after losing count after 15 cycles.
Mine is quite similar with the repeating clicks for a few seconds on switch to standby and a slight hum, which comes and goes (I suspect due to a fridge freezer on the same ring main -UK).
No hum from my 222 or any of my Naim components. There might be a click of the main switch when I turn on the amp. Don’t recall specifically. Nothing out of the ordinary though.
I had no hum when I had a 222, I did hear the click of relays as it turned on and off, as I do with my 333/332 and for that matter with my Star. I don’t think it should be humming that loudly, as other have said, video it and send this to your dealer/importer and/or Naim support in the UK.
Long post, not much info!
The streamer / pre, requires an amp, so what is connected?
Is the noise(s) occurring when the unit is plugged in an alternate location?
The NSC222 doesn’t click as much as the Nova / Atom.
Try turning off everything electrical in your home particularly IoT lights et al, (remember to switch the fridge back on) - does the issue remain?
Finally, there are two link plugs in the rear, if no ps, so with unit switched off, remove and replace those plugs a few times.
Otherwise dealer assist may be appropriate. Just be sure that your electric supply is totally clean and at correct voltage; a professional assessment may be necessary. Hum can be caused by an out of spec electric supply.
It’s connected to an Atom via RCA cables, so using Atom only as a power amp. (Yes I know it digitises everything on input…proper power amp planned for early next year) However even with the Atom off and everything plugged in near off, the issues remain. Humming is now variable but always audible - even when it is quiet hum, as soon as a song finished you are immediately drawn to the noise.
Turning off things is good to a point to identify potential issues, but ultimately I have only one location for the 222 and the fridge needs to stay on As I currently renting its not like I can install a new ring.
I tried replacing the plugs - good suggestion, but no fix.
If it were just a slight hum, i maybe would invest a some kind of power filter, but with the power supply endless cycling for 3 mins or more with clicks and humming…I think It must have a defect.
You can’t use an Atom just as a power amp, and you’ll be going through its preamp first. That may be part of the problem. Have you fiddled with the earth switch on both units? Changing the setting may help, but if the 222 clicks multiple times it sounds unwell. With the 222 you really need a 250.
Looking at your home’s electricity consumption habits? Gathering video evidence? Supplying more information to satisfy others’ need to show off their naim wisdom? You have spent considerable money on a product that appears to be malfunctioning ,just take it back and get a refund, the dealer can do his own investigating if he wants to, maybe direct him to this forum for best guess diagnosis but don’t trouble yourself trying to justify your dissatisfaction. It appears that Naim failed to diagnose the issue before you purchased an item with a known fault so instead blamed their dealer for lacking product knowledge!!
Atom has AV pass-through mode which bypasses its volume control. I have used this setup with the RCA pre outs of an AV receiver. As I understand it effectively works as a power amp in this mode. I’m not sure if it goes through the pre amp section of the Atom. In any case, the humming that come from the 222 is the same if the the Atom is attached or not. I fear you are right - Its quite unwell.
I contacted the dealer describing the issue with a video - they have cancelled the contract and sent a shipping note to return the unit. No questions asked.
I don’t think I will buy a returned unit again and unfortunately full price for a new unit is not an amount I’m willing to invest at the moment. Reading the forum (which I know is dangerous), humming can be quite common if there are any issues with wiring or slightly funky devices in the house. As I rent and move around Europe a lot for work, I can never guarantee my next house wont cause a problem.
I am glad you got it sorted out and although disappointing to have to send it back at least the dealer has acted honourably and you are not out of pocket.
As I currently renting its not like I can install a new ring.
