Poll; Have you ever experienced Naim Transformer Hum?

Many of us can talk about Naim Transformer Hum until the cows come home. Of course this is not necessarily a Naim issue and can be caused by many things, but to see how big a problem it is amongst Forum posters, please indicate if you have ever personally experienced a Naim transformer Hum issue on Naim kit, even if you resolved it at some point.

  • Yes
  • No

0 voters

Naim is not the only brand to have humming transformers. Other torroidals do it too! I’ve had Musical Fidelity power amps exhibiting exactly the same symptoms, likewise caused by external mains influences not the transformers themselves. It is simply a characteristic of this type of transformer.

1 Like

Absolutely, and I certainly dont want to pick on Naim, but it is a possible consequence of choosing high end gear with large transformers that you may experience issues around this area.

I think the poll should state the level. I “experience” hum in the sense that with my ear up to the PSes, I can always hear a little hum. But I don’t usually hear it from a meter away. Sometimes, it gets louder for an hour or two, but not to the point of being annoying and my fridge in the open kitchen or my laptop fan are louder if engaged. My phone app cannot really distinguish this elevated hum from room background level, the app always shows the same ~25 dB.

In my case it’s certainly coming from something outside my apartment or building.

So, strictly speaking I would have to answer the question with yes. But though “experiencing” it, I think it is perfectly normal and I would not say I am “suffering” from it, and if I did answer yes, it would dilute the more affected cases. (Edit: so I voted No)

It might also be interesting if there was a way to vote location (country, apartment vs standalone) to maybe see some correlation. (Edit: I see @feeling_zen made the suggestion already in the other thread)

In my case:

  • No severe hum
  • Germany, urban, apartment building (new, high-quality)
  • No dedicated mains off the building supply as such but the hifi is in its own circuit off the apartment’s fuse box.
  • Whenever I measured (during both normal nearly-no hum and when it’s slightly more), my multimeter said 236/237 V, I could not see a correlation.
  • SCDR (2020), 555PSDR (2019), 300PS (2020), XPS2 (2007, serviced)
  • At the times when there is the slightly elevated hum, there seems a bit of difference between the PSes, but I can’t say it’s one that is consistently worse

Unfortunately I cant change it mid poll. It would be a nice feature that you could have a sub levels where you can give more detail, but that is more a questionnaire than a simple poll, which is all you can do here

I see. Added my info to the post

1 Like

Nap140(serviced)/NAP250(serviced)/HiCap(serviced) medium hum, HiCapDR(New) no hum. Urban UK, Voltage averaging 245V, not on a dedicated mains, 30 year old house.

My “no” is 6 years working for a Naim dealer. The local supply was 240v. If a customer ever had the problem, the complaint never made it to my ears. The customer systems I heard were also local and in detached homes in suburban areas.

Then of my 8 Naim boxes, no hum in a 100v country living in dense urban areas in large blocks of flats.

That said, many friends lived in very rural parts of the Cotswolds with wiring so old it was wrapped in paper and half the outlets still had round holes rather than oblong. And their mains supply came atop a 100 year old wooden pole on reedy looking wire. I don’t at all fancy my chances of getting a good transformer result there had any of them bought Naim.

My answer: no. As in, no buzz that adversely affects my enjoyment.

Hicap DR: faint buzz if I hold my ear up to it. Buzzed a little louder a few weeks ago when first plugged in.
NAPSC: no buzz
NAP 200: no buzz
ND5 XS: no buzz
Nait XS 2: (recently sold) quiet buzz, sometimes a bit louder, but only really audible when close to it.

I experienced this until I upgraded my HiCap DR and 250DR last year to Supercap and 300. I don’t know which unit was the cause.

It would come and go and was quite loud when it infrequently reared its head. This was with a dedicated radial supply.

My retired dealer once discussed the problem with Julian who offered a slightly impractical solution, suggesting that the customer moved house!

I had a Nait 5i with no hum then swapped to 5si which hummed like a swarm of bees so I got an MCRU DC blocker that fixed it. I’ve since moved to an XS2 but since I haven’t removed the DC blocker I’ve no idea if it hums or not.

I sold my SuperUniti because the hum was often loud enough to hear on the couch from 3m away. Tried using an ATL DC-blocker but that unfortunately didn’t reduce it enough to not make it noticeable. The degree of hum varied throughout the day and was also affected by neighbours doing stuff on the net (appartment building).

Currently have a Nova in the same environment which is dead quiet most of the time. Only at the peak times i can sometimes hear a very slight hum, but nowhere near the situation i had with the SU.

Minimal hum from my NAP180 at certain times of day.
Not audible from listening point.

The only one of my Naim boxes that hummed significantly was an XPS and when it did it could often be heard throughout the room. It was enough to cause my very tolerant wife to complain and ultimately was a factor in my abandoning Naim for my main system.


Yes, from 555PS, Supercap & 2 NAP135s. Not any more though.

Have been buying Naim stuff now for 14 years. Pre-owned and new. Nap200/250/300, XPS and XPSDR,555PS and HiCaps. Never ever had any hum. Nada,zero,niente,not even the slightest. Even when putting my ear on the box. Guess it depends mostly on the quality of the mains in your house. Have to say that even my dealer was a bit surprised I never had any problem with it. So guess it is not that uncommon.
For the record, Netherlands,appartment building 16 yo,220V. No dedicated mains.

I used to find my 135 powe amps could be noisy often when an appliance was switched on. Mine or a neighbours?
The best way to cure it was a dedicated spur off the mains and with a 500DR this is no longer an issue. With no music and sitting about 3 feet away from sources there is a tiny hum masked totally with a very low volume level. I think the key is a separate spur.

1 Like

I have never had a hum problem with my SuperUniti at either of two properties, my NAP300DR does hum, but I do not find it a problem from my listening position a couple of meters away.

Servicing the 300 did not change the transformer or the level of hum.

1 Like

I’ve had humming transformers in various components over the years. The loudest and most annoying in some Class-A mono amplifiers back in the nineties. Sometimes both were quiet, sometimes both humming, sometimes only one (but not always the same). Usually a succession of all three. My SN2 is relatively quiet in this regard, the NDAC even more.

1 Like

My memory is a little fuzzy but I seem to recall experiencing the hum with my first Nait 3 in my home in Chicago 20ish years ago. I can’t recall experiencing the hum with any of my black boxes in my later homes though.

1 Like