Humming Naim gear versus alternatives

joerand posted:

This forum consistently sees topics about humming Naim amps and PSU's. "Is it normal", "should I worry", "what can I do" ...

Typical responses "Toroidal transformers", "part of the Naim sound", "dirty mains", "get a dedicated circuit" ...

Other brands use transformers that don't hum, regardless of the quality of mains delivery. 

Is the Naim sound so precious that it's worth tolerating the humming?

Joe,

A dedicated circuit may not cure the hum (it'll only cure it if the corruption of the mains supply is in your own house).

Plenty of other transformers can also hum, but it's more obvious with Naim as they use much bigger transformers to get better dynamics.  So take your pick!

My system used to hum 'til I fitted a capacitor based device to remove the mains asymmetry - and no loss of the Naim sound - so you can have both, even with a difficult mains supply.

+1 for Huge's capacitor devise to remove mains asymmetry (DC Off-Set)  I made mine 3 or 4 years ago & confirm it does not lose any SQ,  if anything it improves it.   But I must add that no matter what filter & no matter how perfect the mains sine wave form, all transformers hum, some are near silent & some are not, thats what transformers do.    My filter stops the variations in hum tone & volume as DC comes & goes.  However since my neighbour who used his garage as a metal arts studio with electric welding has moved,  I suspect I don't have a DC problem anymore.  Whatever my DC filter is staying.

I've owned many Naim devices and never had problems with humming. But perhaps I'm only blessed with bad hearing.

Good question Joerand,

I'm very happy with my humble Unitiqute, but otoh I'm a bit annoyed with the fact that I'm kinda forced and restricted to stick to the little UQ, only becuase of the humming risk with higher end Naim gear.  

I've had 2 Nait 5si's and 1 Nait XS that hummed like crazy.  (I don't even dare to try anything higher up the Naim ladder)

I also tried 2 dc offset blockers/killers. One from AH! and one from Supra. Both immediately killed the hum, but they also destroyed the Naim sound, especially the Supra. (both had a bad influence on dynamics and treble became very polite/smoooth)

I don't buy the 'excuse' of 'Toroidal transformers", "part of the Naim sound", "dirty mains", "get a dedicated circuit".   
I've never experienced any hum with the dozens of other amps I tried over the years. (some of which had similar sized PSU's)

Alco posted:

 

I don't buy the 'excuse' of 'Toroidal transformers", "part of the Naim sound", "dirty mains", "get a dedicated circuit".   
I've never experienced any hum with the dozens of other amps I tried over the years. (some of which had similar sized PSU's)

 The truth is Naim  is too lazy to spend the 25 minutes necessary to correct this problem and they don't give a damn about what their customers think, you're right not to buy those silly excuses. 

SJB

I built myself a large power amp., with a massive Canterbury Windings transformer. It occasionally hums like nobody's business. It's what toroids do.

joerand posted:

This forum consistently sees topics about humming Naim amps and PSU's. "Is it normal", "should I worry", "what can I do" ...

Typical responses "Toroidal transformers", "part of the Naim sound", "dirty mains", "get a dedicated circuit" ...

Other brands use transformers that don't hum, regardless of the quality of mains delivery. 

Is the Naim sound so precious that it's worth tolerating the humming?

When you mention about the humming of Naim amps and PSUs, do you mean both preamp and power amp, or it's the power amp only that hums? Your post is suggesting that all Naim amplifiers and power supplies will hum. However, I do not experience this with my NAC202 and NAP200. This is something new to me. 

Alco posted:

Good question Joerand,

I'm very happy with my humble Unitiqute, but otoh I'm a bit annoyed with the fact that I'm kinda forced and restricted to stick to the little UQ, only becuase of the humming risk with higher end Naim gear.  

I've had 2 Nait 5si's and 1 Nait XS that hummed like crazy.  (I don't even dare to try anything higher up the Naim ladder)

I also tried 2 dc offset blockers/killers. One from AH! and one from Supra. Both immediately killed the hum, but they also destroyed the Naim sound, especially the Supra. (both had a bad influence on dynamics and treble became very polite/smoooth)

I don't buy the 'excuse' of 'Toroidal transformers", "part of the Naim sound", "dirty mains", "get a dedicated circuit".   
I've never experienced any hum with the dozens of other amps I tried over the years. (some of which had similar sized PSU's)

I have listened to the Nait XS in my system and it doesn't hum. I have the NAC202 / NAP200 and both do not hum too. I am slightly baffled by the comments on the humming of Naim amps here. Nevertheless, I do not doubt the humming issue experienced by you and other folks here and believe they are genuine cases. I am curious to know the cause to these humming.

I've not been able to isolate the cause for my 250.2 humming but in truth it only really bothers me when I'm using the room to read in without any music playing, when it really can be a royal PITA. My other half has stopped her negative comments when she goes into the room, I just get the occasional "it's even louder than normal today". 

For obvious reasons I'm loathe to switch the amp off until it's required and if I'm playing music I simply don't hear it, or it's masked enough not to cause me a problem. 

I've got no idea if this is an "easy fix" for Naim without sacrificing SQ but given the amount of negative comments it causes I'm sure they would have already done something about it if they could.

I'm still waiting to get a 10mm dedicated feed into the hifi room but I've been advised by my sparkie not to expect miracles......we'll see.....

DC on the mains was cured for me by using Isol8 Axis mains blocks which filter out the DC. Probably founded upon in certain circles but I've not detected any negative effect on SQ. if anything with all that buzzing gone I can concentrate more on the music! If also noticed that my new 300DR suffers less from it than my old one. The very worst offender was a NAP145 which I sold on when I went back to two channel.

My 200DR is pretty much silent, where other amps have hummed on the same circuit. Has anyone else discovered reduced hum from the latest generation of NAPs?

I have dedicated circuits and earth grounds.  My main plug is grounded by one.   My Nordost box is grounded by another.   This double ground is not code but it works.    The hum that I get occasionally is because the power exceeds 120 volts at my house.  When the load on the electric system is low in the winter, it can be 128 volts.  In the summer, when everybody has the AC on, it is close to 120 and the hum goes away.

The hum on my Naim system is higher than it was with my Mark Levinson system years ago, but it is much lower than it was with the Joule Electra tubes.

I have a dedicated 20amp circuit for my Naim setup. All three of my power supplies hummed due to DC offset. Ran them all into an Audience aR6 PDC (no filtering), and then connected the PDC to the wall outlet with a Isotek Syncro. The end result was silent transformers and no loss of sound quality.  

Not all DC offset filters are created equally. First tried a much less expensive PS Audio Humbuster. It silenced the transformers, but robbed the sound of energy and dynamics.

ATB.

Hook

i have a few naim power supplies - and everynow and then one or the other (especially supercaps) used to hum quite loudly -- not all the time.

however, lately, for some reason, they have been very quiet -- perhaps they simply got bored when i didnt hum back 

this issue has been discussed MANY times on this forum and the answer has always been the same. naim transformers are selected for their sound quality. as consumer, you can choose not to belive that. if this is a serious problem, and you find similar competitive gear that sounds just as good, then it seems perfactly sensible to switch to the non-naim gear.

enjoy

ken

joerand posted:

 

Other brands use transformers that don't hum, regardless of the quality of mains delivery. 

 

Perhaps because the Naim boxes are kept always On while others have a standby button. It 'just my doubt

Mike-B posted:

+1 for Huge's capacitor devise to remove mains asymmetry (DC Off-Set)  I made mine 3 or 4 years ago & confirm it does not lose any SQ,  if anything it improves it.   

So if it is this simple to solve why do Naim not incorporate this type circuit into their amps & power supplies?

I think that the OP's question has been answered. Most don't put up with it because most don't have any noticeable hum.

And most of the rest have found a way to mitigate it.

That said, if you got very unlucky due to your local mains supply, Naim might not be the right product no matter how much you like the sound. 

Similarly, you can't make use of a ground hugging sports car if you live somewhere hilly with pot holes and under snow for half the year. There are other luxury vehicles that you can use though. I beleive the same principle applies to all hifi too. AC supply is just one aspect outside our control. For example, we all discount speakers from consideration because their design may be unusable with the room. 

Morton posted:

Mike-B posted:

+1 for Huge's capacitor devise to remove mains asymmetry (DC Off-Set)  I made mine 3 or 4 years ago & confirm it does not lose any SQ,  if anything it improves it.   

So if it is this simple to solve why do Naim not incorporate this type circuit into their amps & power supplies?

Why not ask Naim,  some manufacturers do incorporate such a circuit. 

Mike-B posted:

Morton posted:

Mike-B posted:

+1 for Huge's capacitor devise to remove mains asymmetry (DC Off-Set)  I made mine 3 or 4 years ago & confirm it does not lose any SQ,  if anything it improves it.   

So if it is this simple to solve why do Naim not incorporate this type circuit into their amps & power supplies?

Why not ask Naim,  some manufacturers do incorporate such a circuit. 

Well it’s a bit academic for me now as currently the only Naim stuff I have left is NACA-5 speaker cable, but it was fear of buzzing power supplies that helped to nudge me away from Naim when I up-graded a few months ago.

Morton posted:

Well it’s a bit academic for me now as currently the only Naim stuff I have left is NACA-5 speaker cable, but it was fear of buzzing power supplies that helped to nudge me away from Naim when I up-graded a few months ago.

So its a bit academic for you to be posting on a Naim forum ?           I think Naim could do a lot better with transformer noise,  I don't completely buy into the story that transformers are the best for SQ,   I don't doubt they are good for SQ but winding noise is not a prerequisite IMO.  My Naim traffo hum's are fairly low & tolerable (since the CDX2 was sold)  but I do notice my two non-Naim PSU transformers are practically silent.

Mike-B posted:

 

 

So its a bit academic for you to be posting on a Naim forum ?           

Ah yes, you are quite right, although I do try and confine myself to the Music Room nowadays.

I've owned a Nait 5i and an XS2. Both hummed at some point but stopped after being left unplugged overnight. Unfortunately I doubt this solution would work for everyone. I've also owned countless number of amplifiers from entry level to high end (some with huge transformers) and none of them ever hummed.

I've said this a few times already and will say it again: I would never put up with an amp that hummed at any price and wouldn't hesitate to kick up a major sh*t storm with my dealer and beyond if ever a quick solution wasn't found.

My NAP200 hums very occasionally, but never loudly or for long. If it persisted I'd buy a brand that didn't hum. I love my Naim stuff, but that would be a deal-breaker.

My gear hums when I occasionally get 'poluted' mains. Even my REL subwoofer hums then...

You ahould hear some of the guitar / bass rigs how those hum with dirty mains. NAIM transformers are polite by comparison. 

When playing live or in a studio, it's practically mandatory to have a noise gate on at all times....

Doesn't really offer a solution to the noisy amps, but all I can add is that my current electronics (non Naim), sans the CD player, have pretty hefty transformers, and they are as quiet as a mouse, they have been completely dead silent for the past two years of ownership.