Is there a FAQ on having a dedicated HiFi Spur installed in your house?

My electrician has agreed to quote on installing a set of dedicated unswitched plugs for my HiFi, and another set in the same room for AV stuff that is on the house main circuit.

Should we create a FAQ on this as so many people end up doing it?
How it works, types of wires and plugs, pitfalls to avoid, any tricks of how to do it well, etc.

Or can anyone direct me towards how to find a particularly useful thread on the old or new Forum that will help me clearly brief my electrician on how to do this, as he’s heard of it but never done it.

BTW, as a matter of interest, are there many cases of Naim users where people have done this and not heard any difference?

Given that there are electrical safety regs applicable here, there’s no way Naim (via the forum or elsewhere) are going to give written instructions on how to do this. Regulations change over time, and between regions, and what is safe in one house may not be in another, meaning that any written advice can never be guaranteed to be both safe and compliant.


Fair point.
I’ll just search the old Forum then using terms like spur, mains, consumer unit…

The word ‘spur’ did the trick…

Here you go Jim - this should get you started with your electrician. For the price of a Powerline (well it was for my particular install) it was well worth doing so I’d definitely recommend it. Source first etc…

Use the diagram as a guide to explain to your electrician what you require. They will be able to install what you need, meet the relevant regulations and will sign off the final installation.



there’s no FAQ on mains installations, and for good reason; The forum is made of members from all over the world, and every country, or even region, has its own electrical code and requirements, so any recommendation for one country/region may well be at best, inappropriate or at worst, very dangerous for another country/region.

Naim have in the past given an outline recommendation for customers in the UK. The difficulty of posting this on an international forum is that it’s only appropriate for the UK.

The second issue is that electrical code is regularly revised and updated, so what may be have been fine and perfectly acceptable in the past, may not be today.


I can confirm that the above is well worth having installed. I had an almost identical installation to the one above about 10 years ago for £800. Best sound per pound upgrade ever.

The only difference in mine, is that I use 6mm twin and earth. 10mm is probably better but installing it and getting it to safely fit the terminals of plug sockets can be an issue.
I also had my radials star earthed, the electrician used a single 6mm earth cable across all the sockets with a single termination at consumer unit.
There is/was a hifi accesory retailer who sold mains products and claimed to have done tests and research into the mains issue. They recommended avoiding the use of RCD if possible, I dont recall the science but they claimed that RCD’s degrade sound quality and recommended RCB’s be used but regs may now prohibit that.
They also recommended Hagar as the best sounding (believe it or not!) Consumer Unit.
Use best quality unswitched sockets, MK or Crabtree if still available.

Oh, and finally make sure your sparky is Part P qualified and able to sign off the work with a compliance certificate otherwise your buildings insurance could be compromised



Sorry, should have said the above applys to UK ONLY

So if I email Naim will they send an outline to me?

Jim, it’s as james_n diagram. The only difference is I have one single 10mm2 cable going from the cu to the sockets and not 3 to each socket.

Thanks James.
In the meanwhile, I have made the following notes from the old forum.
Being untrained in electrical wiring, I may have made errors!
Should I just ditch these notes, or do any of them help fkesh out your diagram?

  • Use cable with 10mm2 conductors.
  • Install one dedicated 10mm2 radial circuit for each powered box.
  • Split the meter tails and install a dedicated small consumer unit with 50 amp breakers.
  • Use a Hagar or a Memara 2000 AD consumer unit if possible.
  • Most of the benefit you hear from a dedicated supply is down to the size of the conductors you use.
  • The writing on my 10mm2 T&E cables reads from the CU to the wall sockets, equal length, all pointing in the same direction.
  • Ensure that there are no joins in the cable between the consumer unit and the socket.
  • The cable will have to be stranded.
  • Ensure that the earth goes straight to the meter board, and doesn’t piggy back off the main consumer unit.
  • MK Logic Plus unswitched sockets are good.
  • It may be possible to chain the sockets together without cutting the wires.
  • Radials may be star earthed, the electrician used a single 6mm earth cable across all the sockets with a single termination at consumer unit.

Also, I have on one wall from right to left:

  • 272 and 150x on HiFi rack
  • Cisco switch, Samsung TV and 2 STBs on a TV cabinet
  • PlusNet router and PV panels data relay box

So how many sockets do I need on which circuit?
thanks again

Possibly yes, if it’s something they’re still prepared to do. It was pretty basic though - as it had to be. In all cases you should comply with current electrical code and consult a qualified electrician.

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Jim - It depends how far you want to go with your Hi-Fi as to how many sockets you’d need but for your setup I’d want at least 2 double sockets (for future expansion) with 2 radials back to the new consumer unit. I only went for one as the maximum number of sockets i’ll ever need is 2 but that’s my particular setup). Cabling can be 6mm2 Twin and Earth (T&E) or 10mm2 T&E. 10mm2 can be more difficult to work with but my electrician had no problems. I’m not sure what the best socket is at the moment but M&K / Crabtree are usually the best bet. I’m sure others can comment on their particular setups and what they find best. Again with this sort of thing as is usual in the Hi-Fi world it’s possible to go OTT with fancy consumer units and audiophile mains installation cables but the main thing you are looking to achieve is to get a low impedance mains supply for the Hi-Fi that is connected as close to the incoming supply as possible - same with the Earth connection.
For the rest of your non Hi-Fi stuff, I would just run that off the existing sockets.

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The outline advice from naim used to be printed in some older user manuals, but was pretty basic, consisting of a single spur running from the existing CU. Ok, but nowhere near as good as a dedicated CU.

Basically its about distancing your equipment in electrical terms from the noisy ring main, lowering impedance, and reducing RFI.

I have a lot of empirical experience over many years, experimenting with different approaches to the mains issue. The diagram above is very much the same as mine and highly recomended.

As well as the other comments I made above, if its practical have your dedicated mains supply connected to a seperate earth spike buried in the ground.

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Perhaps also worth pointing out that mains conditioners and filters are paliative devices. Source first = the mains supply.


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Despite my earlier post…a couple of years ago I spoke to Steve Hopkins at Naim (now sadly departed) and he was happy to make suggestions based on my own location and system. I’m not sure if Naim’s current support staff are willing to give such advice, but you could give them a call and ask.

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Do you think most of the people who get big SQ improvements from installing dedicated radials experience that because they had problems with their electricity supply in the first place? Or is it also good for people who have no problems with electricity stability or supply as well?

I think it gives you greater isolation from other circuits which may be heavily used or carrying electrical noise. It also might allow you to eliminate RCDs which are thought to degrade performance, and ensure the use of unbroken runs of suitable cable. All subject to compliance with local regs, of course. How big the improvements are can be hard to assess, as you may not have the chance to do A/B comparisons with what you had before.

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Yes, that would be impossible.
But it’s striking in what I’ve read almost everyone who’s done it (esp with 10mm2) raves about the improvement in SQ, among a group of people who don’t often rave about things.