Amp and PS buzz

Olek_K posted:

How about isol8 minisub axis? It seems to be designed to combat this dc thingy.

I have not tried that one. However I do not think it is DC as the Isotek Syncro (which to my understanding is a DC filter) did not work out. My humming is quite bad, as it is hearable 5-6 meters away.

Br. Jan

Adam Zielinski posted:

Two questions SISUJAMA;

1. Does your mains supply have a proper earth / ground? You profile does not show your location.
2. What source components do you have? Typically Naim's CD player gounds the whole system rather nicely,  helping to eradicate humming. 

 

Adam

Hi Adam,

thanks for the suggestions.

1) I have tried to move the equipment to a grounded spur without any effect

2) System consists of nac202/nap200/hicap dr/napsc/dac v1 which is fed optically by a bluesound node.

My electrician think that it is something coming from outside my own installation

Location btw is Denmark

Br,

Jan

Hi Jan

Ok - that means you have a normal grounded mains. 

Have you ever tried setting up just your bare 202/200 to see how it behaves?

Meaning - unplug your additional PS, all source components and leave just speakers with your amps.
Does it buzz?
Does it hum in mute?
What happens when you un-mute?

Next step: add NAPS. Does it hum on its own? Does 202/200 start humming?

Step 3: add HiCap...

Final step (a bit extreme) - do you have a friendly NAIM dealer, who can loan you any NAIM CD player? Just plug it in normally into your system, into the CD input and plug it into the same mains spur. 
Of course - I'm not suggesting you should buy a CD player just to ground your system (that would be a bit excessive). I'm merely suggesting this step to see if the problem is really outside your influence i.e.  Caused by some noisy power generator, lift, heating pump, etc etc.

Nearly all large transformers will softly hum, however a buzzing sound, often coming and going, is caused when the transformer laminates saturate when, as Huge says,  there is a DC offset in the mains. Toroidal transformers which Naim use I believe are more sensitive to they are high efficiency designs with good regulation... Thereby offering optimum audio replay performance.

Having the Naim equipment on a seperate spur may or may not make any deffiferrence.. If the DC offset is caused by other users connected to the same substation /down link transformer then having a seperate spur/ring etc will make no difference.

This is nothing to do with earthing, RF, high frequency noise or other such things.

Solutions if particularly annoying include getting the transformer checked by Naim.. sometimes the laminates are a little loose or transformer can be changed, use a DC offset remover... several are on the market if you want to buy one, use a dedicated spur...only possibly  useful if you have a large ring or spur you are sharing your Naim with other naughty devices on it such as hair dryers, tumble dryers, some SMPS and the such like..

DC offset is caused when the current draw of one side of the mains sine wave is higher than the other.. This causes the voltage drop over the mains wiring to off centre the duty cycle of the mains. It's the mains cycle half with the largest voltage(least voltage drop)  that then saturates the laminates of the transformer, causing them to physically make a sharp noise each time they saturate on that cycle ... and it is this that causes the buzz. If there is no saturation, the laminates  smoothly energise and de energise, and this is the soft gentle hum you otherwise hear.

Simon

Indeed.

That is why I was suggesting, checking just a bare 202/200 and then individual Power Supplies to check which of the transformers is the main culprit.

It seems to be a typical Naim thing, this psu humming/buzzing issue. I've had/tried dozens of amps over the years, but only had these buzzing problems with Naim gear so far.  (2 times with a Nait 5si and 1 time with a Nait XS)

Last year I bought a s/h Nait XS from my Naim dealer. Sonically all was fine as expected, but a few times a day an annoying hum/buzz started to gain in volume and hold on for about 10 to sometimes 30 minutes. It was easily audible throughout my 6 x 4 meter livingroom.

The main cause of this seemed to be mains polution. I tried so-called DC blockers/killers. A power strip that eliminates the humming as soon as you plug in your amp!
The first one i tred was from Supra. it directly destroyed the humming, but unfortunately....also the music, making it very slow and smoooooth.
The second one I tried was the AH! (AH! being the brand name) dc offset killer. It also worked flawless, but had a slight negative effect on dynamics.

In the end I decided to sell the Nait XS and I bought a mint s/h Unitiqute one month ago. Very happy with it!

Alco posted:

It seems to be a typical Naim thing, this psu humming/buzzing issue. I've had/tried dozens of amps over the years, but only had these buzzing problems with Naim gear so far.  (2 times with a Nait 5si and 1 time with a Nait XS)

Last year I bought a s/h Nait XS from my Naim dealer. Sonically all was fine as expected, but a few times a day an annoying hum/buzz started to gain in volume and hold on for about 10 to sometimes 30 minutes. It was easily audible throughout my 6 x 4 meter livingroom.

The main cause of this seemed to be mains polution. I tried so-called DC blockers/killers. A power strip that eliminates the humming as soon as you plug in your amp!
The first one i tred was from Supra. it directly destroyed the humming, but unfortunately....also the music, making it very slow and smoooooth.
The second one I tried was the AH! (AH! being the brand name) dc offset killer. It also worked flawless, but had a slight negative effect on dynamics.

In the end I decided to sell the Nait XS and I bought a mint s/h Unitiqute one month ago. Very happy with it!

Thanks for the reply...same here my units hum is hearable 5-6 meters away. Btw I also tried the Supra with similar negative results

br,

Jan

Adam Zielinski posted:

Hi Jan

Ok - that means you have a normal grounded mains. 

Have you ever tried setting up just your bare 202/200 to see how it behaves?

Meaning - unplug your additional PS, all source components and leave just speakers with your amps.
Does it buzz?
Does it hum in mute?
What happens when you un-mute?

Next step: add NAPS. Does it hum on its own? Does 202/200 start humming?

Step 3: add HiCap...

Final step (a bit extreme) - do you have a friendly NAIM dealer, who can loan you any NAIM CD player? Just plug it in normally into your system, into the CD input and plug it into the same mains spur. 
Of course - I'm not suggesting you should buy a CD player just to ground your system (that would be a bit excessive). I'm merely suggesting this step to see if the problem is really outside your influence i.e.  Caused by some noisy power generator, lift, heating pump, etc etc.

Hi Adam

Unfortunately the Hicap/200 makes noise with nothing connected to them. Sometimes they hum at the same time sometimes it is only one of them.

Anyway I will try the unplugging as you suggest

br,

Jan

sisujama posted:

Olek_K posted:

How about isol8 minisub axis? It seems to be designed to combat this dc thingy.

I have not tried that one. However I do not think it is DC as the Isotek Syncro (which to my understanding is a DC filter) did not work out. My humming is quite bad, as it is hearable 5-6 meters away.

Br. Jan

 

In your first post you stated that you tried an Isotek Aquarius, not an Isotek Synchro.  Which did you try?  They are quite different.

Sorry Jan, I got confused between your post and the thread's Originator.

Huge posted:

sisujama posted:

Olek_K posted:

How about isol8 minisub axis? It seems to be designed to combat this dc thingy.

I have not tried that one. However I do not think it is DC as the Isotek Syncro (which to my understanding is a DC filter) did not work out. My humming is quite bad, as it is hearable 5-6 meters away.

Br. Jan

 

In your first post you stated that you tried an Isotek Aquarius, not an Isotek Synchro.  Which did you try?  They are quite different.

Hi,

I tried both (see original post) - i think that the use of syncro with no effect outrules DC.....

Br,

jan

Huge posted:

Sorry Jan, I got confused between your post and the thread's Originator.

No problem. Tried both Aquarius and the Syncro...unfortunately with no luck...guess that I am living in 'no Naim's land' :-)

Being new to NAIM, I must say I was surprised when my XPS started to buzz loudly one morning - I thought it was a fault until my dealer told me that 'this was normal for NAIM'......!!

In my case the XPS stopped buzzing shortly after and I notice that it now only seems to buzz every now and again and mostly in the mornings... (must be related to all my neighbours making breakfast..!!!) 

My poweramp uses two substantially bigger transformer than that used in the XPS and after the first three second on power-up makes no buzzing sound at all.... also I just happened to see a video about Macintosh where they put their transformers in a tub of tar to prevent the transformer laminates vibrating.... so the technology is out there

I wonder why NAIM dont do whats necessary to stop transformer buzzing.... I know that sometimes NAIM do it 'their was' for the sake of sound quality... but other quality manufactures seemed to have solved the problem without impacting sound quality....

fernar posted:

Being new to NAIM, I must say I was surprised when my XPS started to buzz loudly one morning - I thought it was a fault until my dealer told me that 'this was normal for NAIM'......!!

In my case the XPS stopped buzzing shortly after and I notice that it now only seems to buzz every now and again and mostly in the mornings... (must be related to all my neighbours making breakfast..!!!) 

My poweramp uses two substantially bigger transformer than that used in the XPS and after the first three second on power-up makes no buzzing sound at all.... also I just happened to see a video about Macintosh where they put their transformers in a tub of tar to prevent the transformer laminates vibrating.... so the technology is out there

I wonder why NAIM dont do whats necessary to stop transformer buzzing.... I know that sometimes NAIM do it 'their was' for the sake of sound quality... but other quality manufactures seemed to have solved the problem without impacting sound quality....

 

Hi,

I could not agree more. It is absurd paying 8k for a system, just to ad 2k more in dedicated spurs, mains conditioners, etc. to make it work properly....

Br,

Jan

Such is life... Actually NAIM advises against using power conditioners. In a way their new DR technology handles most of those problems anyhow.

'Dirty' mains will always affect every audio equipment. The 'problem' with high end is that it is so revealing...

Complaining about it, it's a bit like complaint about Ferrari being a bit hard and unforgiving on a pot-holled road. It's not the cars fault that the road has holes, is it?
It is a simple fact of life that Ferrari in its quest to be one of the ultimate driver's cars, is also so revealing of the road imperfections.

So it's not NAIM's fault that your mains supply is so dirty.
It is very unfortunate that you suffer that problem, though.

By the way - how did the diagnosis go?

Adam Zielinski posted:

Such is life... Actually NAIM advises against using power conditioners. In a way their new DR technology handles most of those problems anyhow.

'Dirty' mains will always affect every audio equipment. The 'problem' with high end is that it is so revealing...

Complaining about it, it's a bit like complaint about Ferrari being a bit hard and unforgiving on a pot-holled road. It's not the cars fault that the road has holes, is it?
It is a simple fact of life that Ferrari in its quest to be one of the ultimate driver's cars, is also so revealing of the road imperfections.

So it's not NAIM's fault that your mains supply is so dirty.
It is very unfortunate that you suffer that problem, though.

By the way - how did the diagnosis go?

I totally disagree. As mains supply generally is getting dirtier...design should follow - which is not the case with Naim. HiCap DR ultra low noise.....thats a laugh for sure :-)

HiCap is quiet in my set up. And I live in central Warsaw, with mains poluted as one can possibly imagine.

In my previous flat, with no dedicated auio spurs, it was a bit noisy.

Now with a dedicated one - all is quiet on the eastern front

Adam Zielinski posted:

HiCap is quiet in my set up. And I live in central Warsaw, with mains poluted as one can possibly imagine.

In my previous flat, with no dedicated auio spurs, it was a bit noisy.

Now with a dedicated one - all is quiet on the eastern front

Hmm....Copenhagen - Warzaw is not that long a distance - just a matter of cable work ��

Strong statement because it's true...

Honestly if you believe a dirty mains supply is causing the buzzing you want your head looking at. It's the transformer buzzing which has been said already several times on this thread.  I suggest you stop worrying about it and listen to more music. Perhaps installing a dedicated supply and spur may improve things to a degree, but is it bothering you that much to warrant the aggro and expensive of installing such equipment? I personally believe (from experience not just nonsense I've read) that the emphasis on 'clean power' supply's is massively overrated and a marketing ploy to get idiots to part with their hard earned. I'd rather spend the money on a few more noisy mono amps

Lewis posted:

Strong statement because it's true...

Honestly if you believe a dirty mains supply is causing the buzzing you want your head looking at. It's the transformer buzzing which has been said already several times on this thread.  I suggest you stop worrying about it and listen to more music. Perhaps installing a dedicated supply and spur may improve things to a degree, but is it bothering you that much to warrant the aggro and expensive of installing such equipment? I personally believe (from experience not just nonsense I've read) that the emphasis on 'clean power' supply's is massively overrated and a marketing ploy to get idiots to part with their hard earned. I'd rather spend the money on a few more noisy mono amps

Anecdotal evidence...

I have an electrically noisy environment (conducted and radiated), so I take precautions against RFI.  I also have a slightly asymmetric mains supply.  To deal with these factors I built a specially designed filter (total cost £72).  Switching the system between my filtered power sockets and unfiltered ones there is an easily noticeable and difference: Always better when filtered and always improved in the same ways, but the degree of improvement varies from time to time.  The differences are:

1   Lower background smear level in the sound - details are more noticeable
2   Better presentation of instrumental timbres
3   The slight hum from the transformers is markedly reduced.

A clean supply DOES make a difference.

P.S.  I've also designed HiFi amps and I know the theory behind amplifiers, so I also know why this is beneficial.

fernar posted:

Being new to NAIM, I must say I was surprised when my XPS started to buzz loudly one morning - I thought it was a fault until my dealer told me that 'this was normal for NAIM'......!!

In my case the XPS stopped buzzing shortly after and I notice that it now only seems to buzz every now and again and mostly in the mornings... (must be related to all my neighbours making breakfast..!!!) 

My poweramp uses two substantially bigger transformer than that used in the XPS and after the first three second on power-up makes no buzzing sound at all.... also I just happened to see a video about Macintosh where they put their transformers in a tub of tar to prevent the transformer laminates vibrating.... so the technology is out there

I wonder why NAIM dont do whats necessary to stop transformer buzzing.... I know that sometimes NAIM do it 'their was' for the sake of sound quality... but other quality manufactures seemed to have solved the problem without impacting sound quality....

 

1   It's not "Normal for Naim", it usually only happens when the mains supply is out of spec (or someone puts the components on a resonant ferromagnetic shelf!).

2   Just because one transformer is silent doesn't mean they all will be.  The material used isn't tar, it's a potting compound (often pthalate resin).  Every transformer core I've ever seen has been treated this way or has been lacquered to achieve the same effect.  In the case of large torroids a smaller degree of noise often comes from the windings.  The core can vibrate, but this is usually only significant if an asymmetric mains supply pushes it into magnetostriction.

3   Yes there are ways to eliminate this problem, but they all cost additional money and most affect sound quality as well (most other manufacturers just accept the impact on sound quality, particularly on PRaT).  The question is, should the 99% who are unaffected by this have to pay additional costs for the sake of the 1% who are significantly affected?  Which of these options makes commercial sense?

Adam Zielinski posted:

HiCap is quiet in my set up. And I live in central Warsaw, with mains poluted as one can possibly imagine.

In my previous flat, with no dedicated auio spurs, it was a bit noisy.

Now with a dedicated one - all is quiet on the eastern front

Adam,

As they were different flats, they have different electrical environments - the improvement may have nothing to do with the dedicated supply.

If the improvement is due to the dedicated supply, then your problems are being caused internally in your own flat, rather than being caused externally by Warsaw's power distribution network!

A dedicated supply will simply give a more direct connection from the external supply to your equipment, reducing the effect of internal influences and interference.  However it will also ensure that any rubbish carried on the external mains supply also gets a more direct path to your HiFi components!

Huge posted:

Adam Zielinski posted:

HiCap is quiet in my set up. And I live in central Warsaw, with mains poluted as one can possibly imagine.

In my previous flat, with no dedicated auio spurs, it was a bit noisy.

Now with a dedicated one - all is quiet on the eastern front

Adam,

As they were different flats, they have different electrical environments - the improvement may have nothing to do with the dedicated supply.

If the improvement is due to the dedicated supply, then your problems are being caused internally in your own flat, rather than being caused externally by Warsaw's power distribution network!

A dedicated supply will simply give a more direct connection from the external supply to your equipment, reducing the effect of internal influences and interference.  However it will also ensure that any rubbish carried on the external mains supply also gets a more direct path to your HiFi components!

Forgot to mention, now that I've re-read my reply: the flats were in the same building.

I'd say the difference came from the fact that when renovating the new flat, we've paid particular attention to tidying up the power supply. Even down to how the cables were laid out.
Circuits were separated. As an example: instead of just 8 circuit breakers, I now have in excess of 30. Heavy consumption units like air-conditioning, ovens etc are on their own. The whole flat draws its power from a 3 phase-power supply.

So it's probably safe to say that the problems in the old flat were endogenous to the flat.

Conclusion? A well designed power supply probably does help, by simply not creating some of the problems in the first place.

Adam Zielinski posted:

...
Conclusion? A well designed power supply probably does help, by simply not creating some of the problems in the first place.

 

Yes, I'd definitely agree with that!

Naim don't do themselves any favours in the way they mount the transformers – tightly bolting the units to the case just exacerbates the noise problem.     I have four Naim amps (250, 200 and 2x 100).  Both the  100s were particularly noisy to the point that I decided the modify the transformer mounting by inserting rubber O-rings beneath them (units already out odf warranty).   They are still securely mounted but MUCH less noisy.