But unless measured in some way you would never know whether or not it was either your ears, which are not constant , or even if it was a psychological effect like confirmatory bias…
I assume you’re asking about mains wiring, the topic of this thread. I think not such resistance as to cause significant voltage drop would be important - but that is talking in terms of ohms not fractions of ohms. I haven’t a clue as to why, allegedly, heavier gauge mains wiring might improve sound (as opposed to separating the hifi feed from the rest of mains wiring). And of course, as alluded to above, it is not something on which people do A-B comparisons, let alone blind (who has a 2.5m2 cabled dedicated spur alongside one with 10mm2 cable, otherwise identical?). Anyway, if lowest possible resistance is key, what do you make of Naim’s choice of 0.75mm wire for their Powerline Lite, saying that sounds best, though it is 3.33x the resistance of 2.5mm2, an extra 0.063 ohms with their 2m length? And I suspect (but have no test data so do not know) that the contact resistance of plugs/sockets, and resistance of consumer unit breaker, may be significantly more than the difference between 2.5 and 10mm cable for any normal length.
When I had our house built the sparky gave me a table of voltage drops over distance for different thickness of wire. Going from 1.6mm (standard here) to 2mm was significantly less drop over 10m. On a standard 100v supply (103v nominal) the drop is about .4v or greater than 1v for the sockets furthest away. IIRC I left all lighting circuits on 1.6mm, everything else moved up to 2mm, and the main hifi on the 8.2mm. I think the most important thing I did was unrelated to that. Safety earth can and usually does cross circuit boundaries. So to avoid cross contamination, as well as 4 dedicated hifi circuits, I made sure that certain things like aircon, heating, ovens had separate earth cables back to the CU, as did the hifi, as did the regular room sockets (which might get used for audio some day). Effectively isolating earth into groups of noisy, noisier, and noisiest.
If earth (ground) potential is the critical factor, making the resistance to earth (ground) significant to sound quality, then using T&E cable with is the wrong approach as, at least in UK, its “earth” wire, technically its protective conductor, almost invariably these days is smaller than the live and neutral which are the specified size. Whilst running armoured cable would be one way to get a bigger conductor to earth, another would be to run a separate earth wire, which could easily be specified as 10mm2, which is 2.5x the protective conductor commonly found in 10mm T&E. that could simply be added to an existing smaller cable run, e.g. if you have a 2.5mm dedicated circuit, and far easier to route and less costly, but note that for electrical safety reasons the earth connection should be the same as that of the electricity supply, and not a separate earth.
Obviously you can only safely have earthing electrodes in the ground if you have a TT earthing system… and NOT a TNC PME based earthing system which is the default in the UK.
Your electrician will measure the conductivity of your earthing for it to be compliant and if not low enough they will provide additional electrodes or find a more suitable location for the electrode.
A TT system will decouple Neutral mains noise from the Earth… which I just can’t stress how important that is in improving hifi … far more so than seperate radials etc in my experience. But… and this is where in audiophile land there is perhaps a lack of understanding… it won’t necessarily limit specific RFI. For this to be effective, and indeed I do this… you need to measure the earth cable from your appliance to the earth electrode… and then determine what radio frequencies you are wanting to impede… and then you need to ensure your length is a multiple of quarter or three quarter wavelength… avoiding wave length or half wavelength lengths.
So if you have a range of frequencies then you drive the electrode, and then like a hub with spokes of varying lengths to match the above you connect other electrodes to those spokes. Now that does sink RFI effectively.
Alas if you use TNC PME you can’t do this and your neutral/earth will be noisy and you will need to rely to equipotential bindings to water pipes etc as required by electrical regulations in the UK.
One thing of course you must never do is put a local ground electrode on a TNC PME system… if there was a utility fault it could create a fire in your house, and in other cases you could receive a severe electrical shock from touching equipment which of course could be fatal.
I do recommend if you want to lower your electrical noise levels I strongly advise hiring an electrician to convert your house to TT… I think for many it would be like multiple ‘box’ upgrades… and will allow your system that relies on ground earthing referencing such as Naim to take a step forward in performance.
I don’t recommend the RF sinks however unless you know what you are doing (as you could matters worse) and you specifically want to provide a low impedance path to earth for certain frequencies. An electrician typically won’t know about this, that is more the territory of an RF engineer or specialist.
Thank you Simon. Your knowledge is astounding. I hope to read up on and understand some of the terms you’ve used as I’m a complete novice at this. I will consult the electrician and see if he has a handle on this type of setup. Otherwise I may need to hire a specialist electrician who is accustomed to hifi installations.
Thanks - I did look into a lot of this when I knew I had to migrate from PME (TN-C-S) installation a few years back which was for radio reasons rather than HiFi. The improvement to Hifi was a welcome bonus.
As far as moving from TN-C-S to TT most competent electricians should be able to do this as it is not such an unusual procedure.
After routing the cables under my soon to be completed ground suspended floor (concrete pads to strip flooring) my Electrician a couple of hours ago connected me up at sockets and RCB’s. All tested fine.
Three dedicated supplies
Two double sockets on a ring with 4mm cables into one 32a RCB.
Two double sockets on radials with 6mm cable each into a 32am RCB.
I asked him to check the earth ohm resistance for each supply. Bare in mind that we are looking for as low a figure as possible. Here are the results.
Ring measured at 0.02 ohm
Radial one at 0.06ohm
Radial two at 0.07ohm
I am chuffed to death with those numbers as is my sparky. Not surprised that the ring was superior from an earth resistance perspective.
Can you please explain why the ring was more effective for earthing? Is it simply because there is more earth wire?
I believe I already have a TT earthing system so that’s a check
Now I need to decide on cabling. If I stick with my Furutech NCF socket I will have to get a 6mm cable. I can buy a CY armoured control cable for indoor purpose which I hope to run in either radial or ring setup.
May not be wise to run a CY cable in a ring circuit due to the need to earth the outer (armoured) shield at one end only, even if the internal T&E is ringed normally and outer sheaf at one end only it would seem to present as more cable that needs more protection for nothing but extra length cable sake (?)
I don’t fully understand the science but I do know that the lower the impedance on the earth the better and the ring clearly measured better than the radials. Hope that helps!
I’m all set up in the new room as from an hour ago. Plenty of warm up and burn in time needed but still sounded very very good. Going active with 3 x 500DR next Wednesday.
I would imagine many qualified electricians baulking at the thought of such a big fuse for 4mm cable, maybe work okay for a ring circuit if both lines that make up the ring stay safely connected but any haphazard disconnect on one of the two 4mm cables would render the remaining 4mm cable to radial status and then having a fuse too big for its safety.
Although i do like the idea of 4mm ring and the capability of easy daisy chaining multiple 2-Gang unswitched sockets.
Quite right. Electricians find it difficult to believe that the breaker rating even makes a difference. They seem to be under the impression that as long as it meets standards there will be no difference.
And then there is the burn in for a new breaker🤪. My recently upgraded 20A type C started out nicely but right now it’s very very detailed and bright. Similar to how the 500 was during warm up but even more so.
I have another electrician coming this week to quote me for the job of a new fuse box and the radial to my socket.
BTW what happens to the existing wiring for the first floor once I disconnect my socket from it. Would it need to be connected together somehow. I’m thinking it’s a continuous wire that runs with each socket acting as a link right?
Assuming ‘existing wiring’ you mean a ring main? …if so nothing will change with it, just left alone to continue as a ring main.
If you’re presently using the ring main for audio, and an electrician installed an additional radial circuit to supply the audio, then a new wall socket such as an unswitched 2-gang will need to be fitting in the wall somewhere near to the audio, plus will also need a spare fuse position in the Consumer Unit for the new ‘audio’ radial circuit.
Splitting the meter tails and providing a separate consumer unit for the dedicated circuit is key. My first attempt at dedicated mains ignored this advice and used a spare way in the main consumer unit, and frankly it was a waste of time.
Indeed, however this at first needs to be something of a doable possibility, not all dwellings have the option. My post was in response to a question asked by khan84, and i really don’t know if his property allows the option of a separate CU.
A very valid point. With our property, installing a separate CU and circuit for the hi-fi, although theoretically possible, would involve such a vast amount of disruption that I just couldn’t face it. Instead we’ve made the ring that the hi-fi is on as quiet as possible.
