Quite so, from my experience of using mains signalling systems used to automatically switch lights in a large commercial building, (a high frequency (HF) signal is put onto the normal mains system through a conventional circuit and it is picked up all around the building by local controllers.) the HF signal (or noise) finds its way throughout the entire electrical system, if it didn’t the system wouldn’t work. In fact it took a fair bit of effort to prevent the signal going in some areas of the system by means of filters.
I have no doubt that noise from other devices in your home or your neighbours homes for that matter find their way into your HiFi circuit. Whether this matters or not is another issue.
I welcome people to carry on sharing their experiences in answer to the survey - this is a very interesting dataset.
But I’d like to also ask if anyone has any thoughts on what causes the SQ uplift (or worse SQ or no change in SQ).
(From what I’ve read here and on other forums about 75% of people get a large or small uplift in SQ).
My hypothesis is that the main uplift is from having newer wiring replace old wiring that may be loose, ill-fitted, poor quality, rusted, damaged, rotting, etc.
The main probable causes seem to be:
improved Earthing.
new cable and components replace old/loose/damaged ones.
thicker diameter of cable.
quality of MCB (e.g. Siemens Sitor or Gigawatt) and differential switch (e.g. Doepke) cable, plug sockets, CU, etc.
no other electrical items drawing current on the dedicated radial.
whether gear is moved, cleaned, unplugged, and cable dressing, rack maintenance etc. are done (plus the time it takes for the system to come back on song).
any sources of EM noise have to take a longer and less direct route into the HiFi.
shorter route from incoming supply to the HiFi socket(s).
how sensitive the system is to respond audibly to the changes.
I think it’s all of the above in a varying mix per situation.
If you decide to install a dedicated mains/spur, I would strongly suggest to have a good look at the MCB(s) and differential switch(es) used. They are needed but also true evils for SQ. Audio grade alternatives for both from Siemens (Sitor), Gigawatt and a Doepke (diff switch) provide a substantial improvement over any standard MCB or diff switch.
Add earthing to that list and as @RvL says, it’s all of the above and probably more.
And, I suspect, the higher up the kit ladder you go (with bigger toroidal transformers et al), the bigger the gain i.e. you want ‘cleaner’ and ‘unchoked’ voltage.
I concur with your thoughts on doing A/B comparisons, especially with Naim kit in play, as powering-down can mean a week or so in getting back up to par IME.
On another thread there is discussion of the order in which to plug items into the sockets on your radial. I’ve switched my plugs around and it does make a difference, power amp nearest the supply is suggested as best and it works for me. Theory is that it is in part down to current draw, which would point to low resistance radials/new cable/large diameter cables being better.
Its more to do with increased cable size. I tried 6mm twin and earth for a couple of months before changing to 10mm. Everything else remained the same but there was a very noticeable uplift in sound quality. As for transformer hum, the dedicated mains has made little (if any) difference that I noticed at the time.
Thats similar to what I did with the earth, except I used 10mm earth from the consumer unit to the block, then equal individual lengths of 4mm earth to each socket to achieve star earthing. Still connected the earth from the twin and earth cable though.
I wonder if there would not be great gain in just cut 1cm of the cable and replace the wall socket. Having changed these myself in a 40 year old house showing a lot of oxidation and aging on that part makes me think this is a cheap investment in sound quality.
At least undo and re-tighten the connections, it’s suprising how loose they can become in an old house. Probably due to temperature expansion and contraction. When my house was re-certified after fitting a new consumer unit we had one circuit that gave a problem until we retightened a light switch
Before my dedicated Mains, I changed all the sockets on the downstairs ring for MK Logic plus, and I did have to use emery cloth to remove the copper corrosion on each cable. result, no change in SQ, but I felt better with newer sockets
Without adequate juice from a dedicated spur(s), Naim components don’t swing as well.
So this is a critical thread for us.
From the little I know, the wire gauge we use allows for higher levels (and ease) of electrical conductivity (current flow) to the system. A thicker gauge wire has less electrical resistance and hence will convey more current over distance.
6mm gauge for at least 30A spurs which I used on my then olives.
SQ just flowed easier. Appreciable uplift in SQ as reported by other members here.
20A for Classic series onwards isn’t adequate IMO, for the system to be optimised.
10mm gauge mentioned by Mr Happy is really nice… but that would mean at least a 40A MCB on the CU if your home can accommodate that current supplied, apart from the rest of the home’s electrical needs in totality. There is always a current limit supplied for most apartments / homes which will dictate how much current the MCB rating can accommodate on the CU - and we need more juice especially when we pump high volumes for crescendos and heavy bass tracks and the like.
There is a corresponding gauge of wire to the respective MCBs… would ask a trained electrician for assistance to correctly match the wire gauge to the dedicated MCB rating.
I was never a fan of multiple sockets, and still am not. No conditioners. No mains blocks for me either with Naim - though I’m tempted to try the G4 block one day when the new system is set up - which some of us swear by… Prefer to plug the power amp(s) directly into its own dedicated switchless socket, “hydra-ed” straight to the wall, without sharing it with the pre and source. Separate spur for the latter into double switchless sockets.
I’m unfamiliar with what star earth grounding means - anyone in lay terms?
I suspect that you are confusing the current rating of the wiring with the actual current demands. Wiring with 10mmsq cable as opposed to 6mmsq will not result in any increase in the current to the equipment. There is no requirement for a 40A MCB as the actual current draw will never approach this. Fitting a lower value MCB is safer as it will trip at a lower current value. What you would not want to do is to fit an MCB that was a higher rating than the current that the cable is able to accommodate. But lower is fine.
Ah, I see you’ve amended your post! Interesting that it’s 1mmsq in the EU. My understanding was that Naim always claimed that a higher gauge sounded worse.
Pete, I meant the current rating of the wiring as I understand it - and I could be wrong - should match or be within the limits of MCB rating being used. Yes, it’s true and has gotten me thinking since it seems we will never actually use 40A actual current demands and yet, with thicker gauge wire, and higher rated MCBs, particularly for the reference components 500DR and the Statement - have been reported to sound much better. Hence the link between thicker gauge wire and appropriate MCB ratings - but I am not completely sure and am still learning. Not an electrician… lol
Just what I have read that’s been reported, and from my own experience with the dedicated spur to my listening den at that time.
