I suspect that’s partly because they want you to also use more expensive cable
Whether 6mm2 cable will fit will depend on the number of copper cores in the conductor: Solid core 6mm2 (=rods!) has a diameter fractionally under 2.8mm. A large number of strands might minimise air space to be not much more, but in the common 7-strand t&e cable used for mains wiring in Britain each of the conductors of 6mm2 has a diameter maxima of approx 3.1 mm in three places, so won’t fit if the hole is actually 2.8mm. It might be possible to bore out sufficiently, but whether advisable is another matter.
If you’re lucky the socket spec will be wrong, or have poor manufacturing tolerance, with a larger capacity than specified. From this query and the response that appears to be possible:
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The Furutech will go to 8.2mm. Trust me, I’ve done it.
I was once in a similar situation about a decade back. We’d bought a new build in a new condominium and I’d paid for several dedicated circuits. The one in the living room was done wrong and commoned to the LED lights. But fixing it would have involved moving out and $50k worth of reflooring and walling.
I just lived with it and focussed on the music. Why worry about what you can’t change.
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In two days from now I’m completely replacing my lounge ground floor. Hifi will move from a smaller dedicated room into it. I have a great opportunity to run a new electrical supply and have a Carte Blanche with regard to configuration.
After reading a lot of old posts (DB’s views were very valuable) adding my own experiences and conferring with my Electrician (who will be terminating the runs and sign it off) I’ve decided to go with :
Existing 4 x 32amp breaker consumer unit which is tailed off from a Henley block.
32 amp RCB 4mm Ring connecting 2 double switchless sockets (my sparky has experience of terminating those 4mm doubles at the socket end without any issue)
32 amp RCB 6mm Radial into 1 double ……
32 amp RCB 6mm Radial into 1 double……
So 4 double sockets with 3 RCBs used. All runs will go individually through some of the blue 50mm water pipe that I bought in a large reel and is good for this purpose.
This config provides options to switch between the ring/ radials. I will begin with the ring as the “dominant feed” as I feel that this may well be the superior option. A 4mm ring is equivalent to a hypothetical 8mm cable so resistance will be very low and keeps everything (bar switches) on the same circuit.
I plan to plug the 3 x 500’s into their own sockets with my M6 block into the 4th ring socket feeding S1, 2 x Supercaps, 2 x 555, PowerARRAY. The radial sockets will feed my Farad3 /EE8, Phoenix Net, Core and TT P/S. Just does it.
I will report back in the future on how it works out.
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I can"t wait to see pictures of your new set up! The wiring configuration looks spot on.
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Remember this one?
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Thank you Dan.
P.S looking great in the cap 
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I do Jim. However I really have had great results with standard T&E and slow trip RCB’s. I think that I pontificate about set up enough without becoming obsessive 
.
A turning point for me was when I followed what seemed like wise forum advice, by taking my sofa out of the dedicated listening room, replacing it with a basic chair and completely fill out my rear wall with absorption. Sadly neither worked.
I will stick with the plan.
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When my electrician did my dedicated radial circuit, he put in RCBO Type C breakers to deal with the in-rush current , that way, did away for the need to use additional RCDs.
Also consider going to 6mm2 or 10mm2 if possible.
Whatever you end up with, you will enjoy the improvement.
DG…
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Where the heck do you put your drink if you listen from the centre seat of a sofa?
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Thanks Diggy. I have the same circuit breakers as you
As you know the reason for going with the larger gauge cable is to lower resistance. A 4mm Ring is equivalent to an 8mm radial resistance wise, is easier to work with and has the benefit of creating that single circuit for just about all the kit. Dark Bear even prefers 2.5mm in a ring feeding his virtually soon to be identical to mine entire system.
I’m sticking to the plan and just glad to have this opportunity. +1:
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“ I hear ya” as our friends across the pond would say 
Not that I suggest you change anything, as anything above 2.5mm Cable is good. But just for information, in normal PVC cable it’s worth remembering that the earth cable is smaller in diameter compared to live and neutral, which may be one of the reasons Naim suggest 10mm to get max earth size.
Earth cable on 4mm PVC is 1.5mm
Earth cable on 6mm PVC is 2.5mm
Earth cable on 10mm PVC is 4mm
Earth cable on 10mm SWA is 10mm
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Fair point
I thought that was your speaker stand!
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It would be easy to bypass the earth in the T&E and use a separate thicker cable instead. Never tried it myself but who knows?
On the subject of Naim’s recommendations, I had a long chat with Steve Hopkins a few years ago who explained how they had experimented with various options for the demo room at HQ.
He made various recommendations to me, but the main ones he insisted I should stick to were:
•Use a dedicated consumer unit taken from the meter tails, not from a spare way on the main CU.
•Do not use anything less than 10mm T&E, and regular commercial grade stuff is fine, no need for anything exotic.
•Use a single circuit for everything, from a single breaker with one run of 10mm cable. This can be problematic if you want more than one wall socket, but Steve insisted that it was a key point and shouldn’t be compromised. Having tried a couple of runs of 6mm and 4mm in previous rooms and then changed to a single run of 10mm, I have to say that his advice was spot on. The single 10mm run was clearly better.
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Good point, you could perhaps run a separate 10mm Earth PVC cable to the double socket, but like you said, not heard of anyone trying it.
This post is very helpful. I was scratching my head trying to figure out how to get a thicker gauge cable into my Furutech NCF sockets in a radial setup. My aim was to put the 10mm wire in.
So if I’m understanding correctly if i put a 6mm in a ring that will be equivalent to the 10mm. Is that right?
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Sure Khan. But a 4mm ring is somewhere between a 6 and 10mm radial (resistance wise) so more than adequate. Look up Dark Bears historic posts on this subject. With respect to the guys posting earlier If the size of the earth gauge was pivotal then his multi socketed 2.5m ring feeding all those big power supplies would sound pants right? I’m reliably informed that it doesn’t and he did try the bigger gauge multi radial route. Also if one 10mm radial feeding one socket was to supply my full system the wall socket to block/ hydra plugs and cable would have to be really something not to form a bottle neck if resistance was everything. I don’t have all the answers and maybe it’s system dependant to some degree but I have come up with a safe and interchangeable config. It will be interesting to see how it pans out.
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