Humming Naim gear versus alternatives

badlands posted:

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. 

But are they toroids? And are they really as hefty or just large for a non Naim?

And did your previous Naim gear hum in th same house?

It's Cyrus gear, so yes they are toroids, and are quite hefty. 

My Naim gear did hum in the same house.

My OP was based on observations I've read here over the years. I've only ever had a brief encounter with transformer hum, a month ago, when I first installed a new HCDR on my SN2. On initial power-up the HCDR immediately hummed. I let it run for about 10-15 seconds then powered it off. A minute later I powered it back on and it's been quiet since - at least when I'm in the room - who knows what it does when I'm away.

If the HCDR ever starts to consistently hum like it initially did I'd sell it and live without. Too much time spent on racking, room acoustics, power strips, wall sockets, PL's, etc., to let a distracting hum from a PSU spoil the party.

Iconoclast posted:

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.

Its not just amps & big traffo's,  my old CDX2 hummed a lot worse than my Supernait,  it was audible all over the room.   I tried an XPS (purely for SQ upgrade) & although that traffo was quieter than the CDX2 it was still a hummer.   I ended up with an TP-XPS & that is practically silent even when very up close.     Also my current NAT-05 has a hum thats as loud as my Supernait,  so size is not everything.     

Going back to quieter makes  ...........  I have a friend with 4 or 5 Cyrus boxes & they ahve traffos & don't hum.  Then three others with Linn,  dare I mention they never hum because they have SMPS.

Accounts of transformer hum are similar (to me) to posts like "system's sounding better after a shut down", "sounding flat tonight", "sounds a bit off lately", "back on song", "is it the weather?", "human chemistry may be a factor" ... yadda yadda ... and all the rationalizations that follow.

Given the money spent on Naim gear, the tolerance for these inconsistencies becomes illogical for me. The boombox in my shop and my car's audio system provide stable, engaging replay on a daily basis. Why should gear costing magnitudes more be subject to vagaries in the apparent quality of replay output, and why should it be considered acceptable?

Sophistication comes at a cost, but why have it effect the essential purpose for which the money was spent, whether hum or the system sounding "off" on a given day?

I will offer another answer: variations in the voltage, which are quite common have a detrimental effect on a sound quality. 

Another one: perhaps the other makers's gear is    not as revealing to actually show the above. 

Your in-carnaudio has a stable 12V or 24V power supply. Always.

@joerand. I don't dispute that a constant hum is simply not worth putting up with regardless of cost.

But there are inescapable issues around hi end audio. By its nature hi end gear has to be sensitive to increase the level of playback fidelity. Anything that does a really good job of that invariably is more sensitive to other influences too. That's why you hear a modest/no improvement for a cheap n chearful midi system on a rack or connected to a dedicated mains ring but get a fairly large improvement when taking the same care with hi end gear. The hi end gear isn't defective for needing that additional care. It's simply that the lower end stuff isn't revealing enough to show a difference.

That's kind of where I was going with the sports car analogy in my earlier post. Of course I know someone who tore the bumper off their Elise going through a rural intersection with a funny dip in the middle. They also tried to claim a design flaw to Lotus. No pleasing some.

I never understood why my Naim gear hummed, and there is no noise from my current kit. I also upset my last dealers technician when I moaned why the green lights on my 160s should give me an unwanted light show when they dimmed every time the amp pulled some power. They also moaned at my humming lingo, but have to admit Linn took a different view when I mentioned it at one of their workshops, and they replaced it instantly. 

For everyone who's complaining...

As Joe's in America, I'll use the Americanism:

All normal transformers hum, period.

It's a fact.
They just vary in how loudly they hum: Part of that's design, part of it's size and and part of it's just luck of the draw.
I can alter the power supply to make almost any transformer hum loudly.
I have had non-Naim transformers hum.
I've had non-audio transformers hum, I've also known SMPS that whine.
Go and stand by a electricity distribution sub-station, does that hum?

Ignore it, live with it or fit a DC blocker like some of the Isotek or isol8 or DIY devices, or a balanced CTE transformer.

It's not rocket science, it's just physics in action.

Huge posted:

Joe, as you're in America, I'll use the Americanism:

All normal transformers hum, period.

Huge,

Thanks for spelling it out in terms a Yank can understand. My refrigerator hums when it's running. I don't consider it part of my audio gear nor have plans to move it into my listening room.

joerand posted:

 

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

For the record ... both Musical Fidelity and Arcam amplifiers have had transformers which "hummed" (though I would say the transformer buzzes as opposed to mains hum which is through the speakers).

The Naim is much more musical in its humming though :-)  and none of them hummed loud enough they spoiled the enjoyment.

Huge posted:

 

It's not rocket science, it's just physics in action.

I agree: you should explain to the User manual editor's of FM Acoustics electronics, where recommend to clean the electrical conduits otherwise their exclusive amplifiers do not play at the best

joerand posted:

Huge posted:

Joe, as you're in America, I'll use the Americanism:

All normal transformers hum, period.

Huge,

Thanks for spelling it out in terms a Yank can understand. My refrigerator hums when it's running. I don't consider it part of my audio gear nor have plans to move it into my listening room.

Hi Joe,

Perhaps you'd be happier taking a more philosophical approach, after all in Seattle you have to be philosophical about the rain!
When it rains you wear a coat.  If the transformers hum, you fit a DC blocker.  Both are simply physical processes in action, both are driven by energy that has to go somewhere.

Incidentally I have fitted a ferrite to my (old) fridge to reduce it's RFI contamination of my mains, so in some way I do regard it as part of my audio gear (like every other mains powered device that I don't switch off); it's just that it's an undesirable (but necessary) one.  Also, unlike Naim transformers, the fridge can't be silenced (for Mike-B - OK, unless you use an absorptive cycle system), as it uses moving mechanical parts to do it's job.

P.S.  I was once told by a local resident that it only rains once a year in Seattle - from August to June!

A similar effect occurs in Bergen where some of my family live!
It's raining again, so a tourist asks a local kid "Does it always rain in Bergen?"  The reply comes back "I don't know, you'd have to ask my father, I'm only ten."

feeling_zen posted:

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. 

My thoughts as well. I once owned an Italian sports car. When I moved to the country, as expected, the roads were simply to rough and I had to replace it with a better adapted (and better performing) German car.

That being said I still think Naim should look into a solution for the many who's musical experience is tarnished by this problem. And while they're at it they might want to beef up the lackluster headphone outputs on their integrated amps. Sorry I couldn't help myself with that last one.

Does the 250K Statement hum/buzz as well? I would be furious.

Sorry if I sound negativo but being a paying member of the Naim Club gives me the right to constructively criticize.

My 250 hums at intervals, sometimes annoyingly.  Rarely, the 555PSDR will hum a bit.  I wish it didn't, but it has never interfered with my musical enjoyment.

So those of you who enjoy vinyl replay for the sound quality:  perhaps you should be complaining about the annoyances and compromises associated with dust and scratches, fragile styli, flipping the record over, and lack of play lists or shuffle play.

Cheers,

Charlie

Huge posted:

As Joe's in America, I'll use the Americanism:

All normal transformers hum, period.
It's a fact.

IT must be something to do with Naim's topoligy. I have owned many amplifiers and Naim amp is the only company where some ( not all ) of their products hums and they are treated as *normal*.

Various Krell ampss I used to own which had a much larger transformers yet they never hummed, no matter how large they were even when I put my ears right up against the chassis. They must have done something to combat the hum. Possibly a filter or some sort where some Hifi producers do not opt for that due to poor sonic results.

My newish HCDR hums, too. This was probably the loudest of others I have. 300 or 500 amps do not hum as loud ( certainly in an acceptable range at idle ) as well as my older Chrome Bumper HC does not hum.

I have to admit that one of the reasons I am hesitant to upgrade my other amps to DR status is that I would be miffed if they came back with a hum. 

Huge posted:

Hi Joe,

Perhaps you'd be happier taking a more philosophical approach, after all in Seattle you have to be philosophical about the rain!
When it rains you wear a coat.  If the transformers hum, you fit a DC blocker.  Both are simply physical processes in action, both are driven by energy that has to go somewhere.

Philosophical is all I've been on this topic.

When it rains you wear a coat. I guess that's one group's philosophy. Consider is that another group might take the equally sensible approach to simply come in out of the rain. A third group took the time to read the forecast and decided it would be best to stay indoors from the onset. Both these latter groups are aware that coats and umbrellas exist, they just don't want to be bothered having to use them. In the end, all three groups have found various means to the same end - they're all dry - although the first group is the only of the three to remain in the rain.

Just remember that Naim have never apologized about their no compormise approach. The omission of zobel networks on the power amps final output stage annoys some because it limits what speaker cable they can use. Similarly, the omission of anything in the power supplies which would lessen (not eliminate) any noticeable hum is more likely to be because they couldn't find a way of doing it inside the box without impacting the sound quality. Naim are not idiots or new to electrical engineering and nor do they play cheap when building their gear.

Naim have, since way back, put a fair bit of emphasis on not designing things to be tolerant of other issues (room, mains, other components) instead opting to not spend money there and put the onus on the user. When buying Naim, we buy into that or alternatively we can buy something else. It won't sound the same but it may be easier to live with. This is a company that will talk directly to your sparky about recommended mains wire guarges for you - absolutely the opposite of a "fit it and forget it" product.

So while I would never put up with constant loud humming, I know that the expectation here is to resolve the issue ourselves. I used to hate the who hands on approach with Naim and all the PSU requirements. It was one of the reason I was a Linny first. But nothing sounds like Naim other than Naim so I took that on baord and all the sweat and tears that comes with giving it a good environment to operate in. Absolutely not for everyone.

joerand posted:

Huge posted:

Hi Joe,

Perhaps you'd be happier taking a more philosophical approach, after all in Seattle you have to be philosophical about the rain!
When it rains you wear a coat.  If the transformers hum, you fit a DC blocker.  Both are simply physical processes in action, both are driven by energy that has to go somewhere.

Philosophical is all I've been on this topic.

When it rains you wear a coat. I guess that's one group's philosophy. Consider is that another group might take the equally sensible approach to simply come in out of the rain. A third group took the time to read the forecast and decided it would be best to stay indoors from the onset. Both these latter groups are aware that coats and umbrellas exist, they just don't want to be bothered having to use them. In the end, all three groups have found various means to the same end - they're all dry - although the first group is the only of the three to remain in the rain.

Joe, I like it!  Nice extension of the analogy.

The first group though are the only ones who can also still get on with life relatively unhindered by the rain.

Last year I upgraded my olive Supercap to a Supercap DR. I appreciate the boost in sound quality but the DR buzzes like a fridge, to quote Thom Yorke. It is noticeably louder than the 300PS and 555DR to the point where it's quite intrusive if there is no music playing and the TV is off. It's consistently much louder as well -- it doesn't seem to vary with time of day. (But all hell breaks loose when my wife uses her hairdryer!).

I might investigate some of the DC filters discussed here, although I've read elsewhere that these things have a rather negative effect on sound quality.

Adrian_P posted:

Last year I upgraded my olive Supercap to a Supercap DR. I appreciate the boost in sound quality but the DR buzzes like a fridge, to quote Thom Yorke. It is noticeably louder than the 300PS and 555DR to the point where it's quite intrusive if there is no music playing and the TV is off. It's consistently much louder as well -- it doesn't seem to vary with time of day. (But all hell breaks loose when my wife uses her hairdryer!).

I might investigate some of the DC filters discussed here, although I've read elsewhere that these things have a rather negative effect on sound quality.

They do.

I have a solution: get rid of the hairdryer. It's bad for your wife's hair anyway.

Adam Zielinski posted:

Adrian_P posted:

Last year I upgraded my olive Supercap to a Supercap DR. I appreciate the boost in sound quality but the DR buzzes like a fridge, to quote Thom Yorke. It is noticeably louder than the 300PS and 555DR to the point where it's quite intrusive if there is no music playing and the TV is off. It's consistently much louder as well -- it doesn't seem to vary with time of day. (But all hell breaks loose when my wife uses her hairdryer!).

I might investigate some of the DC filters discussed here, although I've read elsewhere that these things have a rather negative effect on sound quality.

They do.

I have a solution: get rid of the hairdryer. It's bad for your wife's hair anyway.

That should be interesting. Telling your wife your Hifi has priority over  her hair maintenance. Let us know how you got along. 

That of course would be a disaster.
It's all about the positioning.. getting rid of a hairdrier is beneficial for the health of the hair. You could supplement it with some statements about argan oil too and it's benefits.
Never mention your Naim....

Adrian_P posted:

... (But all hell breaks loose when my wife uses her hairdryer!).

I might investigate some of the DC filters discussed here, although I've read elsewhere that these things have a rather negative effect on sound quality.

Then the hairdryer is using the mains inappropriately - get her a better one that uses two heating coils instead of using a diode.

If your mains supply is so poor it has an asymmetric waveform, then a DC blocker will almost certainly improve sound quality.  If your main supply is perfect the DC blocker will probably degrade sound quality (but then you won't need it anyway!).

In short if you really do need one it'll improve the sound, if you don't need one then you really don't need one and fitting it will be detrimental!

Adam, I like your thinking but I think the hairdryer is here to stay. However, the buzzing issue I have is not when the hairdryer is in use (when it is much worse as expected but it doesn't happen that often, thankfully). I can live with that, but it's the constant buzzing at all other times which is quite intrusive.