Noisy mains

Straighteners, hair-dryers etc.. will make just about any large toroidal transformer buzz like an angry hornet.  A purr is fine.  Conditioners and filters may improve this (or may not), but invariably they do something to the sound of Naim kit that makes it less engaging and interesting to listen to - some much more so than others.  Plenty on here that has been written on this subject, so if you have a spare week or so, you could run a search and have a read...

Three mains cleaning gizmos which have made a SIGNIFICANT and POSITIVE difference to the performance of my system(s). a) dedicated mains spur: the biggest and most cost effective upgrade bar none. b) RA Silencer on the AV system cleaned everything up. c) RA MegaClampUltra: I bought this to protect the big system from mains spikes. Not only does it do that but it dramatically polished up the sound from the system, instantly. A night and day revelation. Silly name, though. Does the system hum? Yes. Is the humming quieter and more stable? Emphatically so. 

You might like to try the Kimber weave powerkords too as they reduce RFI and mains noise to a degree.

I have not tried the Purifier itself, but you have 60 days to try it and send it back if it doesn't do the trick. You have nothing to lose.

Richard Dane posted:

Straighteners, hair-dryers etc.. will make just about any large toroidal transformer buzz like an angry hornet.  A purr is fine.  Conditioners and filters may improve this (or may not), but invariably they do something to the sound of Naim kit that makes it less engaging and interesting to listen to - some much more so than others.  Plenty on here that has been written on this subject, so if you have a spare week or so, you could run a search and have a read...

Sounds like plenty of bedtime reading. 

Very true. Can't go wrong with a 60 day trial. I may just have to accept the noise till I can get a dedicated mains supply installed 

AS Richard said,  lots of bedtime reading  ......

However its worth keeping in mind that hair-dryers etc cause asymmetric distortion of the the AC mains power supply when they are running half power on heat and/or fan,  full power is not an issue.  They use a half wave rectifier that blocks half the 50Hz sinusoidal wave form. The resultant asymmetric wave form means one half does not mirror image the other half & the resultant mismatch behaves like DC & inrushes the transformer saturating the windings & causing a small movement in the windings & iron core,  its the movement that makes the transformer noise.  

The asymmetric wave can pollute all the house circuits, but that is not always the case.  A mains spur will help in most situations,  but its not guaranteed.  Mains filters & clamps are normally not much use as they address only common & differential mode noise,  not specifically DC.  There are purpose made DC filters available so if you do go the filter route be sure it actually says it will filter DC.  Another solution is a balanced mains transformer,  but that's a big box & their is no guarantee that transformer won't hum.   Maybe agreeing a time the hair-dyer or straightener is used,  or accepting that its something that will happen for a few minutes is the most cost effective.

Hi Finkfan

In May 2015, I started a thread called "Suffering from those transformer hum blues?"

It is one of a number of threads on this forum that may be helpful for you.
Happy hunting!

Best regards, FT

Thanks guys. I've never been listening to music as the transformer starts its loud buzzing so I don't know what impact it would have on sound. 

Hi Finkfan,

You could accidently remove the fuse from the hairstraighteners? Just a thought....

Or get a mains conditioner for them! 

Hi Finkfan,

You could accidently remove the fuse from the hairstraighteners? Just a thought....

On a serious note, the Jan issue of hi fi choice, reviews the Lindy 6 way mains conditioner power strip, it gets 5 stars, nullifies interference from anything plugged into same ring main...and it's surprisingly only £45. 

Thanks for info....question,is it actually any good? 

I've got one for my tv, sky etc. Its ok for that. But not man enough for the hifi. You get what you pay for. And as Mike B says, doesn't do anything for the DC 

Balanced mains could be interesting though. 

Hi Finkfan, Mike above addresses why almost certainly your Naim transformer hums when the hair straighteners are on - its a DC offset on the mains - or in other words the AC is not centred on 0 volts. This causes the transformer to saturate - and toroidal transformers that Naim use are renown for saturating and making a vibrating type growl with the tiniest of DC offsets. Hair dryers, straightens, irons etc often use a cheap method of heat control. Half heat is often achieved using one side of the mains, full heat is use both sides. Using just one side of the mains in a high current scenario is in most settings going to cause the mains to go asymmetrical.

The best solution will be a DC offset remover - and there are several on the market. It is worth noting that dirty mains doesn't usually make the transformer growl, so a DC offset remover wont clean the mains - but will make it symmetrical and make your transformer as happy as it can be. A dedicated radial circuit can also help reducing the DC in the mains caused from an asymmetric load on a different ring or radial

Simon

Hi Simon

Thanks. It all makes sense. As I'm planning on moving my hifi into my 'office' later on in the year. So I'll obviously install a dedicated mains supply for for it. If I'm still suffering then I guess a DC offset remover is the way to go. 

Its not surprising really with all gadgets l, gizmos and chargers etc that the mains takes a bit of a bashing. 

Finkfan posted:

Morning. Has anyone tried an RA mini purifier near their system? My Cdx2 has a gentle 'purr' most of the time, but when a pair of straightners were switched on in another part of the house over the weekend, the 'purr' became more of a growl. I know a separate mains supply would be best, but due to the distance from the board that's out of the question. Any other recommendations? 

unless you are sure that mains is causing underperformance of your system in terms of its ability to play music, then i would do NOTHING. Transformer hum/growl or whatever is something a naim owner learns to live with -- and it will happens whether you have a radial or not -- probably independent of wire gauge that you use (i am on 10mm sq and the supercap on superline sometimes dedices to do this horrible growl solo -- sometimes, but rarely, the 552PS also... but none of this affects sound quality that i hear in any way...

good luck and ...

enjoy

ken

And alas a dedicated mains supply does not guarantee to eradicate transformer hum.

It certainly improved sound quality for me but hum left very much as was.

SJB

ken c posted:

Finkfan posted:

Morning. Has anyone tried an RA mini purifier near their system? My Cdx2 has a gentle 'purr' most of the time, but when a pair of straightners were switched on in another part of the house over the weekend, the 'purr' became more of a growl. I know a separate mains supply would be best, but due to the distance from the board that's out of the question. Any other recommendations? 

unless you are sure that mains is causing underperformance of your system in terms of its ability to play music, then i would do NOTHING. Transformer hum/growl or whatever is something a naim owner learns to live with -- and it will happens whether you have a radial or not -- probably independent of wire gauge that you use (i am on 10mm sq and the supercap on superline sometimes dedices to do this horrible growl solo -- sometimes, but rarely, the 552PS also... but none of this affects sound quality that i hear in any way...

good luck and ...

enjoy

ken

The thing is I'm not sure if my system is under performing. I don't think it is. It sounds great. And I'm more than happy with it. A dedicated supply is a must. I can live with the transformer hum. I'm sat a couple of feet from my system now and it's growling a little. No surprising as pretty much everything than can be on in the house, is. I know it will calm down later and sound better later tonight

wenger2015 posted:

On a serious note, the Jan issue of hi fi choice, reviews the Lindy 6 way mains conditioner power strip, it gets 5 stars, nullifies interference from anything plugged into same ring main...and it's surprisingly only £45. 

I have one of these and effect is highly noticeable, but as I've pointed out in several other threads, it's not an effect I liked.  It has exactly the effect Richard described early on, a less engaging and more restrained sound, and strangely airy.  Some people may prefer it, other electronics may benefit, but this was not so for me with either my current Naim system, or previous Cyrus kit.  In both systems I left in place for over a month, was frustrated by the effect much of the time, and immediately relieved of that frustration once removed.  

However, I actually would recommend plugging the hair straighteners into one.  Mine is now used for all the SMPS stuff, TV, PC etc.  The fridge even has a mains filter on it, but the hifi will not be having one added again.

I guess it's just a case of living with the lesser of the evils. 

Despite having dedicated mains supplies to my audio systems, my NAIM emits different hums on different days sometimes it's caused by RFI, by mobile networks, by a heating pump goin on and off in a basement.

Not much I can do about it.... An RFI filer / power surge strip does help, but it never eliminates....

I doubt RFI will make your mains transformer audibly hum, even if you were a bat... it might set fire to it first if extreme however..

To add some background to my previous post:  My CDX2 hummed & the hum changed its tone & volume sometimes.   I diagnosed this as "DC" offset,  read up on it & found some good information on a specific filter design.  I used the theory & designed & built my own. This fixed the hum tone changes but the transformer still hummed.  gggrrrrr  !!!