Noise and DC on mains and new radial

Adding a dedicated mains circuit with its own separate consumer unit will give a degree of isolation from other appliances in your house, but you'll still have a house full of appliances running. The test you've done, if I've understood correctly, has turned all of these appliances off completely, which is going further than just putting them on a separate circuit, so maybe has a greater benefit. Despite this, I would recommend going for a dedicated mains supply. Having recently installed one with its own separate consumer unit, I would agree with others on the forum who have found it very worthwhile. No experience of the Airlink thing, though.

Thanks Chris. That puts my little experiment into excellent context in a way which hadn't occurred to me. Shame it's more than a radial will achieve. A second but dedicated mains feed on a second meter, perhaps?! But it was interesting to see the effect those other elements are having on the sound quality. The Airline, as I understand it, eradicates DC from the hifi radial which, in so doing, has been shown, here, to reduce/eradicate transformer hum and reduce sonic harshness. Whether it does so in all instances is moot. I'll definitely go ahead, though. Sparks coming next week to measure the incoming power so we can select correct BPU. 

It's best to have a separate consumer unit just for the stereo. Split the meter tails with a Henley block. 

Thanks HH; yes, this is the route I'm pursuing. My sparks not very happy about trying to fit 10mm2 cable into a socket, though. And disagreements here about whether it's sonically more beneficial than 6mm2. Old arguments never conclusively settled.. 

A second meter sounds a bit OTT to me! Do you really want two meters, and two separate electricity accounts?

Nope! Tongue firmly in cheek Wonder how much it would cost though! 

eagle3333 posted:

Thanks HH; yes, this is the route I'm pursuing. My sparks not very happy about trying to fit 10mm2 cable into a socket, though. And disagreements here about whether it's sonically more beneficial than 6mm2. Old arguments never conclusively settled.. 

If you only need one (double) socket, getting a 10mm cable to fit is perfectly possible. Your electrician might think you're nuts, but he'll be able to do it. 

Ideally I'd like 3 sockets. One for 4 x hydra - NDX/252-SC/DAC/250; one for turntable; one for phono amp. 

Fitting two 10mm cables into a socket to run multiple sockets on one circuit is a challenge. You will need agree something with your electrician that he is happy to instal within the regs.

Yep safety and regs first. I might go for 6mm. There's so much conjecture about whether 10mm is necessary. Has anyone explained scientifically why 10mm is preferable to 6mm in the hifi environment?

Naim advised me that 10mm would sound better than 6mm, so that's what I did. 

Right HH. Well I guess they'd know something about it. I might ask them for the rationale though. 

It's worth talking to Naim about this, they'll be able to make recommendations based on your location and system. Their suggestion to me was to use a separate consumer unit, 32 amp type C MCB, 10mm cable and unswitched sockets.

Thanks Chris. Will do. I suspect the advice will be similar. 

anyone who fit 10mm2 cable is putting the socket under mechanical stress and it is poor electrical practice, the socket is not designed for that.  which ever company who says it is ok they should seek the advice from experience persons . 

What do you recommend Audio1946 and why?  

I went for a 6mm ring, so two runs of 6mm. Effectively, it's 12mm.

It's been in a couple of weeks since it went in and the differences makes over the normal ring is astonishing.

Keith

I also used a consumer unit which has a 100a isolator switch instead of an RCD (supplied by Russ a Andrews). This is fine as long as the socket is labelled for hi-fi use only. Finally, I have an earth spike.

I think you may struggle with 10mm2 if you want more than one double socket. I found that with 6mm2 you could just about take the feed to others - I have 4 double sockets. I guess you could over come this if you say wired 3 radial circuits with 10mm2 to three twin sockets. I'm not sure if this would mess with the star earthing arrangement you can achieve? It seems very important with Naim systems and may be more important than 10mm2 or 6mm2 cable choices? Having tested my system on the house circuit and the dedicated circuit I can tell you the difference is greater than black boxes.

Thanks All. Voltage measurement next Wednesday and will be interesting to see what's actually coming in. Meantime, I'm going to stick with just one double socket. Family friend sparks sucked in much air when I mentioned 10mm2. Thinking. A dedicated earth sounds like a good idea in order to keep the Hifi radial away from the main CSU but I'll let the sparks advise on its feasability/safety. But Even then, isn't the Hifi radial still subject to upstream influences from the main CSU, before the meter?

Hi Eagle, yes indeed, which is where some form of low impedance DC blocker can sometimes (but not always) be of benefit.

Thanks FT. I'm going to put in a balanced power supply which is meant to sort out DC. Was going to put it in the radial but Airlink recommended to put it in straight after the meter so it controls the feed to main CSU as well. Which kind of ties in to your comment.

That is where my BPS is too. Hope the installation goes well. I also opted for an Airlink BPS and 10mm2 radial supply. Some of the Airlink products have several output taps, which allow you to control the output voltage in 10-12V steps. This was helpful for us, as we could drop the output from 242V to 230V, which apparently helps "take a little stress off the Naim power supply components" without adversely affecting sound quality. I started a thread about this about 2 years ago.

Best regards, FT

.. and very informative it was too thank you! Can't remember if you listed which BPS you went for? They're talking about the 7000 but this seems excessive for me. 

The exact model is in the old thread. Airlink recommended it to me. It was a BPS5000 something.