Electric supply spur radials or ring main

Here again, made a few changes my source is a known week link, NDS or NDX2 I’m using the NDX BT
1 have the 282 and the 252 I had a pair of HC’ and two Nap 200
I have the 242 configured for my Kudos T606. I have a SC which know powering a 252
I know added a Nap 300
So I have some options. And will keep the pre-amp that delivers the best. I can go active with the T606 and the 242 option one two nap 200 or nap 300 onnthe HF and a nap 200 on the LF and at a later stage stump up the cash to balance it with two nap 300. I have two sets of chord Sarum. Upgraded with Sarum T banna plugs. I also have a pair of Rogers SL3/5a some SL6 with original stands and a pair of Sonus Faber concerto. Plan to given them all a good run with the NDX BY 252 SC Nap 300 chord Sarum and see what the deliver. So power supply, radials for each bit of equipment is possible because I’m renovating my home and will be fitting a compleat new rewire so I have the chance to get it right strait of the bat. ring can have one spur I’m not sure if a number of radials would be a better option or just plenty of sockets in a line in a ring main. I have no idea how much power I would actually be using or what would be the best way to supply power to my entire system :thinking:

You need to get a local electrician involved who will be able to recommend the correct installation compliant with the rules in your country.


I’m assuming you are in the UK, as I think only the UK has a ring. If you are re-wireing, then I’d go for a single separate spur using 10mm cable from a separate Consumer Unit to a single or double socket. You can then use your favourite Powerblock for your devices
Some people will suggest multiple 6mm runs from a dedicated Consumer unit to single sockets (one per hifi device). Both will give an improvement, but peoples recommendations will vary here

Here is also a wiring diagram that has been posed before - give to your electrician, and watch him laugh, but perceiver.

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Just to note, the diagram @GadgetMan reposted is a pre 18th regs version.

As others note, just use the diagram as a starting point to show your qualified electrician who is best to advise you for your particular circumstances and to meet the latest regulations.

Plenty of threads on here discussing dedicated mains, so worth a search.


:joy: Thanks for that I was thinking radials :grin: one for each bit of equipment. Which might be a bit overkill but still in my comfort zone financially.
So I guess another question won’t hurt what about having the power supply fed from the right kind of batteries. Now that probably wouldn’t be so cheap. It might even cost a small fortune but you never now I might be able to afford it. It would be good to know how and if it could actually be done on a reasonable budget. If affordable How would it be done. :thinking: definitely a job for an electrician. Knowing just how much it might cost might make me think twice

I am toying vaguely with the idea of installing a dedicated supply. I say vaguely because it will be a considerable upheaval, mainly because of the absurd location of the CU, which is basically at the back of the inside of a kitchen cupboard - we live in a 1930’s bungalow. Don’t know if I can be bothered as the system sounds superb anyway. But the thought of getting better performance for a relatively small outlay is tempting…

Anyway the point of my post is this. Most people seem to recommend 10mm2 wiring. I did this at our last property, installing a single radial to a double unswitched socket. It never really sounded quite right to me. The bass seemd bloated and slow, and it just sounded less musical. Returning to the standard ring main was a revelation. The sound became far more balanced and the whole thing became far more musical.

So I’m wondering whether 6mm2 is a better option, and if a ring configuration may be inherently better than radial? I’ve heard this suggested in the past.

Any comments from those with experience welcome.

Did you split the meter tails and run the dedicated supply from a separate consumer unit? Without doing this I found little or no benefit. I also found that a single 10mm cable worked best, and thinner cables weren’t as good.
This was after trying various different, more or less dedicated supply arrangements. It was after talking to Naim what I settled on the separate consumer unit and single 10mm cable. These were the key things in Naim’s recommendations, and from my experiences it seems that they were right.

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Hi Chris,

What I remember was specifying a separate CU with tails back to the meter, so completely independant of the main house CU. Then 10mm2 cable to a single double unswitched Crabtree socket.

That sounds about right. It worked very well for me so I’m not sure why yours would have sounded worse.
Was the earth cable also connected directly to the earth terminal by your meter, not via the main consumer unit. I’ve seen electricians do the latter, just to save themselves 5 minutes work.

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Yes, I there were no connections at all between the dedicated supply and the main CU. The electrician I used was actually quite understanding and didn’t ridicule the idea. In fact after I explained what I wanted and why he actually went home and read up on it!. When he came to do the job he said that from what he’d read it seems people had noticed significant improvements and he was keen to do the best arrangement possible.

I don’t recall what make of CU was used, and I don’t know how important that is. I do recall reading that some sound better than others, but no idea which ones.

I would be a little suspicious of anyone who claimed that they could make a meaningful comparison of different consumer units affecting sound quality!


What is your view on shielded twin and earth? I have seen this advertised on various sites. I believe Furutech make a version - though expensive. In view of the amount of EM radiation floating around these days from wireless networks etc, I wonder whether this could bring any benefits?

When running the cable, remember you dont have to go through the house. You may well find it easier to run the cable outside the house, e.g. outside up to your loft, across the loft internally, then back out above your living room, and down to come back into the house. Or even go around the house. Both options will probably be cheaper than a second hand HiCap. If you do go outside, then you could use Steel Wired Armour (SWA) cable which is effectively shielded, providing you connect the outer steel to earth at the CU end only.

In terms of running off batteries, then I wouldn’t see that as a SQ improvement necessarily. Remember what you are after is clean AC electricity. The Inverter that comes with battery backup doesn’t to my knowledge ever come in HiFi grade. That’s not to say it’s worst than your main, just not neccessaily better. There are a few people that have battery backup powered by Solar panels, and I think I’ve only every read one case where the SQ was dropped when using batteries - all others don’t notice a difference.


Thanks. Yes In think it would definitely need to go outside, but still a bit of an upheavel due to the required location of the socket. Why is it important to connect the steel covering at the CU only? If connected at the socket as well will this cause any issues?

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Shielding tend to be connected only (source) at one end to work well. Remember though, I am only talking about the outer steel shielding. The inner earth core must still be connected to the socket, so ensure you get twin and earth (3 core) SWA.

I delayed my dedicated supply for years due the potential upheaval, but in the end, it all worked out very well.

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Thanks for that - understood. I’ll see how things go. One or two other non-hi-fi related things to get sorted first. I’ve pretty much got the system how I want it now. Can’t sensibly go any further as we are now retired, but it sounds superb. Adding a dedicated supply would be the final piece of the jigsaw and it’s very tempting. Probably won’t happen until next spring or summer, but good to have all the specs ready. Thanks again.

I’ve never tried shielded T&E. Again Naim’s advice to me was to stick to regular cable as used in domestic wiring from a recognised brand such as Prysmian, so that’s what I did.

Having said that, when I had an LP12 my Linn dealer mentioned that I should use shielded fire alarm cable. That was over 30 years ago and I didn’t have a clue what he was talking about at the time, so I ignored his advice.

I wonder if they actually meant “Pyro cable”. Doesn’t usually get used in the house though, but no reason why not I suppose - other than a pain to terminate IIRC.

Add one more voice supporting:-

  1. Simple shielded cable - 1 x 10mm or 2 x 6mm.
  2. Cable from the meter directly via Henly block and dedicated CU.
  3. Earth back to the meter or to a spike in the garden if you have one.
  4. Good unswitched sockets daisy-chained with the aforementioned cable.
  5. If you run around the outside of flat or house, it’s usually easier and cheaper ( and cables can be buried).
  6. Get a decent sparks to do the work.
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Ah yes. Linn and Naim dealers seemed to come out with all kinds of seemingly bizarre advice back then. When I had my 42-5/HiCap/110 and LP12 there was only one double socket available where I wanted to place them. No problem I was told. Just wire the HiCap and 110 into the same plug and it will sound better that way anyway. I thought he was barmy as I had never heard of anyone wiring two separate things into the same mains plug and it seemed downright dangerous to me. So I bought a Duraplug trailing socket from B&Q, from which I removed the neon of course. Little did I know that what he suggested was in fact a Hydra!