A dedicated radial of 2 x 6mm into chained unswitched sockets was recommended and reduced noise floor, esp 4pm-8pm.
My understanding is that the specific issue of mains hum would need a BPS or perhaps just a decent DC blocker.
Good luck!
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I used a Hagar CU and I’m very happy with it.
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Same here James!
The extended length of run made 10mm2 T&E the most appropriate option for us too in order to minimise supply impedance and ensure that those Naim power supply reservoir capacitors all filled up as fast as possible.
Best regards, BF
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If you need / prefer multiple sockets then (reg’s permitting) a 6mm2 ‘ring’ circuit would facilitate that and effectively give a lower impedance link than a single 10mm2 radial circuit. Plus it better maintains the integrity of a single circuit as opposed to multiple radials. That said, a single radial and socket plus a hydra is my preference now.
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I put in 2 radials:
Lapp Olflex Classic 110 CY 10mm sq to Furutech (G) single socket. This cable has a tinned copper braid and PVC outer sheath.
And Belden 83803 (12 AWG) cable to an MS HD Power (G) duplex socket. This cable has (7×20) tinned copper conductors, Teflon insulation, 100% Beldfoil shield with 85% tinned copper braid and a Teflon jacket.
The thin Belden cable had a circuit impedance of 0.08 Ohms and the fat Lapp cable measured 0.04 Ohms.
The Earth loop impedance of the Belden radial was 0.07 Ohms, of the Lapp cable was 0.06 Ohms, and the house ring main was O.41 Ohms.
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A Dedicated Mains is always a good idea, whether it helps your humming or not.
In terms of Humming, suggest you read the following for a list of all the possible causes
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I have not installed a dedicated circuit yet…but when I do it I will be installing 10mm mains cable and a bigger dedicated earth cable - probably 16mm. Quite how you terminate 16mm cable at a mains socket…I am not sure…
Stu, I fully understand where your coming from. I’m in Canada for comparison a standard grade outlet is maybe $2, a Cryo treated Hubbell is $50 & the Furutech NCF Rhodium is $300+. When you look at just the cost of an outlet $300 is completely ridiculous, but after installing it, I believe it is probably the best $300 I’ve ever spent in audio (I’ve spend far more in different upgrades for far less improvements in performance). I’m fairly confident that while your wallet won’t thank me, your ears most definitely will. The Furutech Discussion thread has numerous posts about this subject, so check it out if you’re looking for more info.
Edit: I’ll add, I have used Cryo treated Hubbells in the past (which are a “budget friendly” recommended upgrade here). With them installed it was, “I think I hear a difference, maybe?..” With the Furutech NCF Rhodium installed I sat for hours with my mouth open, shocked, continuously saying, “how can just an outlet make that much difference?”. And I know some will say, you probably only think you hear an improvement because of the money you just spent. I have bought a number of different things over the years (tweaks in the same price range, etc) that were non returnable & didn’t like what they did to the sound.
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I thought that Naim had solved the problems with humming transformers at the new 200- 300 series. But it seems that I was completely wrong.
Well sort of. Firstly its worth restating that the issue is with using a toroidal transformer, and therefore nor just a Naim issue.
In their new kit, they address this by using a standby mode that turns off the toroidal transformer, and uses a small SMPS power supply to keep certain electronics alive and ready. So when in playing mode, the hum will still potentially be there.
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Thank’s for the reply
So, is an Airlink all that is needed to isolate a hifi system from the rest of the mains ring such that a dedicated radial isn’t then required? That would certainly be good to know as it would save all that electrical work (my dedicated hifi room is also on the opposite side of the house to the CU in the garage).
P.S. Any reason for picking that particular model?
If you are thinking of having a balanced power supply (BPS) for your music system, then for safety reasons it is best to consult your friendly qualified electrician first.
The BPS changes the effective voltage of the power cables coming out of it, which means that either the whole hifi needs to be on the BPS or none of it. Half measures are best avoided.
Oversimplifying matters a bit, normal mains in the UK has:
Live wire = Brown colour = Circa +/-240V
Neutral wire = Blue colour = 0V
Earth wire = Green & Yellow colour = 0V
These are correct for input to the BPS.
However, the output from the BPS is different
“Live” = Brown = +/-120V
“Neutral” = Blue = -/+120V
“Earth” = Green & Yellow = 0V
Hence it is important that the output from the BPS is its own, isolated, dedicated radial.
The use of BPS is well understood and indeed standard practice in several commercial sectors such as hospitals, many recording studios etc., where a “clean” supply is needed. BPS is less common in a domestic environment so best to check with a qualified electrician first. The wiring and isolation is not difficult but it is slightly different.
I hope this helps
Best regards, BF
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That was my issue, but in the end I let the electrician do what they are used to doing every day - running cables. That’s not to say he wasn’t a little miffed at a stiff 10mm cable. We went up the wall by the garage, through the loft, then back down the other side, then around the corner slightly to my living room. ~35 meters of SWA cable used.
If you ask your electrician to ensure there is enough of a cable in the garage (as per photo supplied earlier by Bluesfan) to later add an Airlink BSP, then you will always have the option for the future.
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That’s pretty much what I was thinking would be necessary.
Just so I’m clear, are you saying I couldn’t just plug the Airlink into a mains ring socket and then run all of the hifi off it, as I would need a dedicated radial as well?
From what I recall, they do supply a plug in device, but bear in mind that they can hum themselves, so best out of the way.
Thanks, that makes sense.
Agree with your sparky. Different opinions on here but you only do this once so separate 10mm cable per twin socket and if you have the space a seperate cable into twin socket per power supply. You can always use one if you prefer but at least you have the choice. I find the multi spur option gives the most open soundstage. There are specialist twin sockets available (I use Russ Andrew’s super sockets) that are better than MK in my opinion. The older MKs were great but current are cheap and tacky IMO. I’m sure your local dealer would be open to you auditioning alternative twin electrical wall sockets 
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The BPS5120MP is not the sort of device that would enhance the appearance of anyone’s room. It is an industrial piece of equipment that should be hard wired into a building’s mains circuits.
If you would like to use a BPS in your music room, then Airlink makes a few smaller devices such as the BPS1500 which is equipped with a standard IEC mains socket on its input. Something like a Naim Powerline (or similar) could be used to connect it to your mains wall socket.
When deciding what to use for our system, I asked the (very helpful) Engineering Director of Airlink about BPS sizes. He recommended adding up the VA sizes of all the hifi power supply transformers, then doubling it to size the BPS. With a Supercap, a pair of 135s, a 555PS and some smaller bits, our total came to about 1500VA, so a 3kVA BPS would be okay as a minimum. Allowing for a bit of future upgraditis, we went for the 5kVA model instead.
Hence, you may need to consider the total size of your system’s power supply transformers when sizing your BPS, especially if you want to use a smaller one in your music room.
I have seen a number of posts over the years, warning people not to use a BPS in their music room in case the BPS itself hums. Our experience is that we have never heard our 5kVA BPS hum and I have listened out for it on numerous occasions.
Hope this helps, BF