Hi,
I’m in the process of setting up a new hi fi room, running a pair of PMC actives with a NSC222 and a Rega P8, and I have a couple of options regarding power.
I will be passing a new 6mm armoured 3 core cable from my garage to the room. Garage side I will connect using either a new consumer unit or to an existing unused MCB in the current CU - that’s the first decision I need to make (depending also on what my electrician agrees is possible).
In the room I have the option of either using a single unswitched outlet with a Wireworld Matrix extension, alternatively connect the mains to a number of unswitched wall plugs and connect the equipment to those. Any general advice or specific suggestions, also what would be the best way of wiring up the multiple wall plugs should I go down that route (I’m thinking, probably in my ignorance, either daisy chained or else connected each with independent wiring to some kind of distribution panel)?
Many thanks!
Welcome to the forum.
Have you tried a search for this information.There are already many threads about mains supplies.
I would certainly use a separate consumer unit wired to the meter, not a spare slot in an existing consumer unit. Having tried both, I found no significant benefit to the latter method compared to just using an existing ring circuit.
Naim strongly advised me
to use a single circuit from the consumer unit, not a separate circuit for each socket.
As Chris said, this is the other alternative that some of us have used. I used a single 10mm2 SWA cable.
Thank you very much, extremely useful! In the meantime I have checked out another couple of threads on the subject also - there’s some extensive knowledge on the forum but not easy to filter out (pun unintended!), and also some conflicting views.
It seems clear that an independent CU is the way to go, should be definitely possible in my case. However in the room itself, are there any benefits between having a single outlet with a quality extension block vs multiple unswitched wall outlets? And is it OK to connect up the outlets in sequence or would it be preferable to connect each independent to some kind of distribution panel?
Or maybe (as I suspect) connecting to an independent CU gives the bulk of the gains, and the rest is really optional so long as quality sockets are used?
I think your question’s will have multiple answer from various people, and no consensus. I went with Chris’s previous response which is backed by Naim (10mm2 cable to a double unstitched MK socket) The possible issue with multiple runs of 6mm cable is (in my view) ensuring the lengths of cable runs are identical, so ensure cable impedance is identical. Separate CU with its earth going back to the incoming earth are big points in going down this route
Thanks @GadgetMan - so I imagine you are using a power extension on that unswitched socket to connect the equipment (presumably more than 2 pieces of kit)?
I have my Atom HE on dedicated mains. The active PMCs are on the ring main, which is what I was advised to do, because they have switch mode power supplies. The Rega also has switch mode. I’d just get one double unswitched socket on the end of the new mains, and use 10mm cable rather than 6mm. Make sure the Earth from the new CU goes back to the meter, rather than piggy backing of the existing house CU.
Yup, using an atlas 4 which is star wired
You only really need SWA cable if you are running it exposed outside. The galvanised steel armouring that is wrapped as a twist in SWA is not really an effective RF shield.
If your cable routing is inside you may find an SY (steel braided) or preferable a CY (copper braided) cable better, as their braided shields are intended as RF shielding.
From a quick google i can only find 4 core 10mm2 CY cable in UK electrical factors rather than 3. (there does seem to be 3 core 6mm2 CY cable easily available), SY 3 core 10mm2 also seems readily available.
CY and SY are also a lot more flexible that SWA, so a much tighter bend radius around corners etc.
Agree. In my case I was running the cable out the house, up to the loft, through the loft, and out the other side and down to the living room - 35m ish. We did use 3 core SWA, not sure where from, but Screwfix sell 3-core “PRYSMIAN 6943X BLACK 3-CORE 10MM² ARMOURED CABLE”
Just check that the cable is fitted in the correct direction 
That’s really interesting and sparks off a load of new questions in my mind. Maybe some of what I am going to say is obvious to many on this forum, but I am quite new to the Naim game (at least to this level of discussion, my prior exposure is a humble Unitiqute) so please forgive me.
From what you say I draw the following conclusions (some of which may be totally rubbish):
- The recommendations regarding power delivery on this forum (and specifically in this thread) are targeted principally at Naim equipment
- Naim kit is more sensitive to quality mains and benefits from such improvements more than other brands (or lets say more than PMC/Rega which make up the rest of my (and @HungryHalibut 's) system)
- This is due to the type of power supplies that they utilise (Linear mode vs switched mode)
- Switched mode power supplies cause interference on mains which negatively affect Naim kit so best kept on separate mains circuits
- Overall, if a compromise is to be had, there are more gains to be made by keeping Naim kit totally separate to other kit (which uses SWPSs) even though said other kit may be on “poorer quality” mains, as opposed to putting the lot together on a mains supply of the type described in the diagrams above.
If anybody is happy to comment on the above, even simply a True/False against each point, that would be fantastic. I have so much to learn from you guys!
Legno, I think it’s really important here to consider that most advice given here will apply to the UK only. Even Naim’s own basic recommendations are UK specific and don’t lend themselves to be used in other countries. So any installation will need to be compliant with the electrical code for your particular country and area so it is deemed safe. You need to discuss with a qualified and accredited electrician for your region.
Yes absolutely agreed and thank you.
This discussion is proving immensely valuable and will give me a basis of discussion with my electrician. I am from Malta and I believe that our power systems are very similar to UK’s and based on them (in fact we use the same 3 pin sockets and plugs). One difference (there may be more) is that from what I understand in the UK the earth is provided by your national grid, in our case each household needs to install an independent earthing rod (I have a 2m copper earthing rod buried in the floor of my garage for example). But in any case, ultimately it will be up to my electrician to recommend and install.
Some have found a ring main better than a radial circuit. It may be worth considering having 2 radials with a double socket on each and 1 ring main on new consumer unit. And having 2 double sockets for the ring main circuit.
That way you won’t need a block. I don’t know how you are running the cables. From outside or inside property? It depends on your cable route what solution you take.
Some I know have 6 separate radials 10mm for each box. Others have several ring mains and radial circuits. This kind of job you only do once, so you might want to think about how you will use your system and to plan for potential expansion of your system.
If I ever do my mains again I will have a separate consumer unit. And something similar to what I described above with a mix of ring and radial circuits.
This is correct, but the earth rod you describe is considered by some to be superior. It’s primary purpose of course is to provide earthing which is crucial to electrical safety, but for HiFi it also provides the signal ground, and it is in this respect that your ground rod, if correctly installed and specified, is considered to be superior to the arrangement we typically use in the UK.
If the rod is too small, or the ground around it is too dry, it can be a poor solution, but your electrician should be able to test this to ensure that it is working well.
That’s good to know.
I had the earth rod replaced round 6 months ago because of some issues I was experiencing after I installed a PV panel and battery system (MCBs tripping, strange fault codes on the PV system) so I should be fine in that respect!
The rods actually can attach onto the end of each other so you can have them installed and lengthened, reducing resistance on ground potential further. It starts to get expensive though piling meters and meters of rods straight down to hades. However, simply having a dedicated earth that is cometely isolated from the rest of the house’s mains earth isn’t too pricey at all. You would need to discuss with an electrician to iron out the fine details according to what electric code in each country permits.
Though not in the UK I believe the arrangement I have is also perfectly valid for UK standards. I have two earth rods. And two conumer units. One earth rod supplies the safety ground and neutral for one consumer unit. The other rod supplies the safety ground and neutral for the dedicated hifi consumer unit. So this is a twin TT arrangement. There is no shared neutral or safety ground with the neighbours, only shared live phases - which is unavoidable for everyone.
My experience was adding dedicated earthing and a dedicated rod was not a significant expense at all.