An audible noise inside NAP 250.2

I’m sure it will just be the transformer buzzing. Nothing to worry about, but can be annoying if it’s loud. My CDX2 does it, but not loud enough to distract once it’s playing though 

It is pretty random how much the transformer buzzes/hums. They all do it to an extent only some are audible outside the case.

CJ

Yes it's mechanical transformer hum. Nothing to worry about in the Naim world. 

And if it's coming from the box itself rather than the loudspeakers, it's definitely not a ground loop. 

Best

David

If it is a hum it is 50Hz (60Hz) from the transformer. If it is a buzz then it is 100Hz (or 120Hz) from the transformer laminate. In either case it is the transformer.
What causes it is the mains quality - either distorted mains waveform due to something on your house circuit drawing a lot of current and distorting the waveform, or a DC-offset.

If it is always there, even late at night, then it could be a DC-offset and you should get an electrician to look at your mains - it is an easy test if you know what to do.

If it comes and goes, or varies in level then probably someone on your circuit making large power demands.

DB.

Thank you so much for your help.

AP 

AP,

have we by any chance spoken about this in a common friend's shop not later than Monday..?

M.

palanhifi62 posted:

Thank you so much for your help.

AP 

Welcome to the Forum AP.

I was in your position 3 years ago, new to Naim Land, as one member put it.

My experience with Hi Fi was exclusively with Linn, coming from a full blown Active System.

Linn stop supporting their Older Gear, and my Pre-Amp & Active Crossover went out, thought I would give Naim a shot.

After all, it started with Linn/Naim, back in the day.  

Linn Amps were tanks, no problems, but Sold all three, needed the funds for Naim Land.

No Buzzing Amps with Linn, and the music flowed effortlessly with my Active System.

Long story short, the Buzzing was a turn off, but the Amps were Richer, Thicker, and with my 282, Clear, Clean, and this was Passive Tri-Amped Briks.

Trade offs, I would imagine the large transformers, contributes to the Naim Sound.

PRAT = Pace, Rhythm, And Time!

Enjoy Your Music, The Why!

Allante93!

My old Naim dealer told me a tale about a customer back in the day berating Julian Vereker at a Hi-Fi show about his buzzing NAP 250. 

“It’s designed and built to sound good” replied JV - “If the buzzing bothers you, put it in a cupboard” 

Ah; those heady, simpler pre-Fraim times eh?

John. 

IIRC, at least one Naim principal used to have all his power supplies and anything with a big transformer in a cabinet in the kitchen - linked through holes drilled through the wall from the living room. Problem solved.

My mate, the builder across the road, has all his kit, T/T, pre, power amps, the lot, located in a room adjacent to his listening room. The are connected to his speakers which are the only components in his listening room, via speaker cables passing through small holes in the dividing block wall.

Sounds amazing.

I have my 250 and psu underneath a sofa, with the speakers to one side and the rest of the system on a rack to the other side.
This does an ok job of reducing the hum whenever it occurs. And I don't have the poweramp/psu transformers over or under the rest of the system. 

This setup works fine for me. And the wife appreciates that the visual box count is smaller this way  

Claus

TT in another room !!!  all that walking to flip a record over would wear me out.   

Claus posted:

I have my 250 and psu underneath a sofa, with the speakers to one side and the rest of the system on a rack to the other side.
This does an ok job of reducing the hum whenever it occurs. And I don't have the poweramp/psu transformers over or under the rest of the system. 

This setup works fine for me. And the wife appreciates that the visual box count is smaller this way  

Claus

No heat dissipation issues I presume, Claus? The 250 can become quite warm at modest volume settings.

John. 

John, no I don’t actually. It did shut down once during a summer party some years ago, but otherwise no. There is 5-7 cm between amp and bottom of sofa, and we live in an old house where the temperature usually is around 18-20’ under the sofa, a little higher on the warm summer days. But then again, most of the time I listen at moderate volume levels  

It’s very practical really, since I don’t have spare shelves on my rack for the two boxes now sitting under the sofa 

Claus 

I had an audible hum from my 250dr which could be noticed from a distance (2 meters) with no music playing. Whilst it did not bother me I decided to try a balanced power supply for SQ reasons. This did have a positive SQ impact but another positive side affect was it removed the hum.

naim has not got any magical design with transformers., if they are more prone to buz/hum  compared with others used else ware , it is a design flaw with either construction/position /manufacture  period

It's slightly off topic, but I am amazed at the number of times I see wives mentioned in the context of audio choosing, buying, placing, and at how often said wives are responsible for some form of imposition or impediment.

I wonder if UK people wouldn't have done a better choice institutionalizing divorce instead of BREXIT.

M.

J.N. posted:

Claus posted:

I have my 250 and psu underneath a sofa, with the speakers to one side and the rest of the system on a rack to the other side.
This does an ok job of reducing the hum whenever it occurs. And I don't have the poweramp/psu transformers over or under the rest of the system. 

This setup works fine for me. And the wife appreciates that the visual box count is smaller this way  

Claus

No heat dissipation issues I presume, Claus? The 250 can become quite warm at modest volume settings.

John. 

Ime the 250.2 gets a bit warm, the 250 olive/CB not

Max_B posted:

It's slightly off topic, but I am amazed at the number of times I see wives mentioned in the context of audio choosing, buying, placing, and at how often said wives are responsible for some form of imposition or impediment.

I wonder if UK people wouldn't have done a better choice institutionalizing divorce instead of BREXIT.

M.

Speaking of wives and on-topic...

I just realised that the my wife's hair straigthener is causing transformer hum in my NAP 200. You would think it's just a heater, but I have tested it and it is 100% certain it is a cause.

Do your own test...

Probably the motor in the hair dryer - lots of RF from them.  

No motors in hair straighteners! I suspect it's because there is going to be a very crude voltage reducing circuit in there, partly to make the heating pads work equally across the full range of possible voltages 110-250 volts ac.

best

David

My wife’s hair straighteners have always given my CDX2 a real buzz. My 250 and 272 seem unaffected. 

rmatosev posted:

Max_B posted:

It's slightly off topic, but I am amazed at the number of times I see wives mentioned in the context of audio choosing, buying, placing, and at how often said wives are responsible for some form of imposition or impediment.

I wonder if UK people wouldn't have done a better choice institutionalizing divorce instead of BREXIT.

M.

Speaking of wives and on-topic...

I just realised that the my wife's hair straigthener is causing transformer hum in my NAP 200. You would think it's just a heater, but I have tested it and it is 100% certain it is a cause.

Do your own test...

Just tell the wife she looks lovely with curly hair.

I don't think the OP will update us on his 'issues' with the 250... But let's say that he's either lucky or smart and now has a new 250DR vs a consistent discount and perhaps he could have had his electric meter's life saver checked better. But not my business..