Balanced power supplies

I read on a post that @DaveS commented on (Hydra Cable) that using a balanced power supply can help reduce line noise. I am looking at the different options provided by Airlink Transformers and I can see ones categorized as " Advanced Filter Balanced Power Supply" and ones categorized as “Standard Balanced Power Supplies”, any hints on which is a better option? I recall reading that any filters and power conditioners can be detrimental to sound quality when used with Naim systems.

The problem with a lot of mains conditioners and filters is that, in doing the filtering, they can increase the line impedance. An amplifier needs a supply that is as low as possible in line impedance, because of the need for sudden current draw during transient changes to the music it is trying to amplify… I use an Airlink balanced mains transformer, but without the filtration bit to good effect, as it cancels out noise on the mains without increasing the impedance. Hope this helps.

With Airlink, you can send back if you are not happy. What’s important is what type of line noise are you trying to fix? E.g. over voltage, DC offset, noise created by appliances on your Ring. For over voltage, you will need to look at the advanced balanced supply, as they can drop voltage from 250V to 230V. Suggest to call or email them, as there is one person there that is familiar with Naim customers.

My LP12 dealer (Chris Brookes) is trying to persuade me to try an Audioquest Niagara power supply before my entire system, which he reckons is meaty enough to cope with any sudden / major transient power draw. That isn’t answering anybody’s question but… there was a chap (called Marc I think) on one of the previous versions of this forum who had a balanced power supply and found it very good on his Naim system

Indeed. It is very good on mine.

We use an Airlink BPS5120MP. There is a thread called “Suffering from those Transformer Hum Blues” on either this forum or the old one in which I relay our journey down that path.

A search should help you find it. Otherwise, a search for Airlink should get you there.

Airlink offer several types of BPS. After speaking with Airlink’s incredibly helpful Engineering Director, we went for the one listed above, as it blocks so called DC offset and also allowed us to step the voltage down from a measured 242V to 230V.

Best regards, BF

Good grief! I’ve just visited the Airlink website, and the prices of the transformers have trebled since I bought mine six or seven years ago!

If you’re buying from the US, Equitech are generally considered the gold standard for non filtering balanced power supplies.

Sadly they aren’t certified for my country.

Thanks for all the feedback, I am trying to manage the noise from the other appliances in my home, and the sheer number of noisy switching power adapters that I can never isolate. I am unable to get a dedicated mains line to the Hi-Fi rack so the next best thing I can think off is to try this balanced power source… I also suspect I have voltage irregularities but can’t measure that for certain…

Naim I understand do not approve any filtering, and in their experience can worsen the sound, however in the real world people may have much dirtier mains than Naim would have tested under, so if you cannot control your supply quality (e.g. by a separate dedicated main circuit possibly) then we have to try other options such as BPS. Getting someone qualified to measure your mains voltage would give you an idea if its too high, as that may influence your BPS model decision.

i second airlink transformers great bit of kit performance Vs cost

i use BPS2000 - Standard Balanced Power Supply to good effect

as dedicated mains sadly not an option at minute, done a number of A/B tests and it makes a significant difference SQ wise with it in place and is a simple plug an play affair (i use a naim powerline from it to my wireword matrix 2 block and all my kit hangs of that)

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One thing to be careful of is where the balanced power supply is fitted and the type. If it is a toroidal transformer and if DC offset is problem on your mains, then you want it fitted in line near the consumer unit out in the garage or something. Because they can tend to move DC offset hum from hifi components to the balanced power supply itself.

So if you are going for standard plug-in model to sit on the rack, an IE design will be better as they are largely immune to DC offset hum.

Also remember, they won’t help at all with earth feedback pollution. If that’s a problem that you have actually identified, then a dedicated earth for the hifi separate at every level from the household earth is really the only way to go.

Thinking of an Airlink myself…
Where should it be positioned? before the dedicated CU or on each 10mm cable going out from the CU to the plugs?

Consult the manual and your sparky. Whatever is done, it must conform to local regulations.

of course it would be a sparky who does the job.
just wondering if one Airlink is sufficient to feed the whole CU or if others have used one per outgoing cable (like one for the power amp plug and one for the source/pre components) ?

I would have assumed its after the CU so that its protected by the Fuse in the CU, however I’m sure Airlink can also advise along with your electrician

Time for a dumb question…

What are the earthing arrangements through (eg) an Airlink transformer box?

A question for Airlink I expect for the model you choose. Clearly you need to clamp a good size earth cable

I’m not clear what you mean. Sorry. Can you explain?

Further digging on the Airlink site suggests we are talking about a star earth inside the box connected to the centre tap on the transformer secondary. I’m assuming inlet and outlet earth (and the case) also connect to the star point. I never did find a link to the page actually on the site - it was a link from a google search.

Does anyone know if Naim have a view of using a balanced supply?

As far as I know they’ve never mentioned. Their dislike of conditioners is well known but BSPs are another thing entirely. I’d actually be surprised if they didn’t use them at the factory.

Then again, I’m constantly surprised.