UK, I have many boxes - 250s x 3, XPS2, 2 x Supercap and I often hear the transformers hum but I haven’t bothered to find out specifically which box(es) is / are humming.
Sometimes they suddenly start humming, presumably when something else in the house turns on but, I haven’t bothered to find out what.
When music is playing I can’t hear the transformers humming anyway.
Mine is a large room, so I am possibly sitting further away from the boxes than others.
Living in a remote part of the countryside with my mains carried over above ground cables with trees etc blowing against them on occasion can’t make for great mains quality anyway!
PS. I can’t see any actual “Poll” to vote on, or is it purely stating here our findings?
Ah, yes!
Apologies, I didn’t read it properly and not having the means to measure my mains, so didn’t respond to the poll directly.
However, I’ve always thought of the UK being 240v so I responded just now.
I’d be interested to correlate transformer behaviour to earthing arrangement. I’m also lucky that my overhead (rural) supply is very close to the transformer and is consistently at or close to 240v. I have my own TT Earthing arrangement which I’m sure also helps regards general system noise.
I believe most countries mandate a TT earthing arrangement.
I strongly doubt the earthing arrangement affects the hum. Mainly because several countries in general have no mains earth at all so their cores are left unearthed.
What might be interesting, when more results come in, is how many of those affected in the UK have this problem on a normal radial versus a ring main. The latter being an idiosyncrasy of UK wiring (and the reason for needing fused plugs). Certainly over voltage looks like it may be a factor here but the number of responses is still just too few to draw a conclusion yet.
I have only recently started to hear intermittent buzzing from my Naim power supply. I have traced it to our washing machine and occurs each time, and only when, the washing machine drum is tumbled back and forth at low speed. The washing machine is on a separate circuit from the HiFi. Our voltage is typically just over 240V and usually exhibits a smooth sine waveform with very slight and smooth flattening of the peaks suggesting the presence of a small amount of odd harmonics. I’ll get around to measuring them some day, but I have very little issue with noise from my Nain boxes, so I’m in no rush.
What really matters is does it affect the DC power on the equipment internal power rails and thus the potential to affect sound quality, given the measures that Naim take in their regulated amps and PSUs I suspect not. Of course this is how it should be, Naim and the others design and manufacture a product for a world wide market where varying mains quality prevails, you want your product to work well everywhere. I suspect HiFi has an easy ride in the UK where the utilities provide a comparatively high quality of electrical supply.
Indeed. Remember neutral is common to earth and carries the difference in current between all connected devices. So any imbalance is generally going to enter the mains this way and cause an offset.
Certainly looking at how your centre tap from earth to neutral in the CU bears some attention. I’ve not actually experienced leaked noise on the mains from motorised things since moving to Japan. It was chronic in the house I grew up in the UK though. No humming Naim stuff though. OTOH, unless the property is very old, I suspect an electrician will confirm it is up to code.
Yeah that is really the problem… or maybe they are and just aren’t many
But seriously, working in retail in the UK, no customer ever mentioned it and we know that in the forum, problems are magnified because misery loves company, as they say.
I suspect there are a couple of additional effects, going on. One is that Naim sell far more units now than they did years ago. Another is that the buyers may well be new-to-Naim - and are less accepting of ‘quirks’ like transformer noise as being acceptable in exchange for performance.
More customers, who are more demanding, put simply. And - as you rightly say - those with no problems don’t make a fuss.
I’m not quite sure what this thread will show one way or another. The question here is problematic; have you ever had a problem with Naim transformer hum?
It’s relatively easy to make them hum or buzz. My (ex) wife running her hairdryer would get the toroidal transformers buzzing, same with anyone in the house using an electric blanket. That’s as it should be. However, at other times the transformers have been pretty much silent. But if I were to answer the question posed, then I would have to answer yes, even though it’s not really an issue for me.
I was thinking the same. I’ve had Naim for nearly 40 years and on occasion I’ve had hum, particularly when living in shared houses. Over the last 25 years, with good mains, I’ve had no hum at all. Over the 40 years I’ve had hum probably 0.00001% of the time. So I have to answer yes, which seems the wrong answer. I’ve therefore not answered.
@HungryHalibut and @Richard.Dane you can choose not to respond or you can choose to respond in the way that you feel matches the spirit of the investigation (which would be useful).
Though for the record, I suspect many people who ever had a Naim box hum have never had any other bit of hifi with that problem… though that would be more complex than a poll lets us dig into sadly.
I totally reject the notion that it’s easy for them to hum otherwise people would be whining about their electrical appliances left right and centre. Though we could certain do a “Do you have any appliance of any type (that isn’t Naim) that has a loud transformer hum?” poll to test that.
Personally, I’ve never experienced this outside of a 2Kw step down transformer. Suspect it’s not more than an unlucky minority, but, having seen the topic be one of the absolute constant forum bugbears am open minded enough to suspect there’s something to this issue and it may be more than there should be and may be a pattern to the issue. If I was Naim, I’d want to turn the stone over a bit more.
That’s all fine, but you are never going to get a statistically significant result from a small and self selecting audience. People may find the poll a bit of fun, but it’s never going to be anything more than that.
That’s certainly possible HH. You are 100% correct. But you don’t know until you try. And people who don’t try never achieve anything… though they never fail or waste their time either.
My chrome bumper amp is barely audible. Then again it is plugged into a dedicated 6mm radial with klangmodul 16A fuse. Separate consumer unit for the extension and new earthing under the extension foundations. Also a new substation as part of the works in our village.
The main system is in our flat that has the same 6mm radial and klangmodul 16A copper fuse, but the house is shared with 4 flats and causes issues with the Naim boxes on and off.
That said, 28% is rather high already
Yes but it will demonstrate at least that the power supplies are sensitive to the elements so to speak. Of course not everyone will have done the upmost to provide the best possible supply to the HiFi that you have done. I’m looking for trouble here probably but when have statistics with a large number of variables ever been useful? At best they give an idea but of course can be biased or skewed. Most problems that I’ve worked with ended up with a lovely normal distribution
but when have statistics with a large number of variables ever been useful? At best they give an idea but of course can be biased or skewed. Most problems that I’ve worked with ended up with a lovely normal distribution