Mains and earthing

[ursus262]

As a matter if interest, I noticed that at the back of the Naim Uniti (which I have), there is the option of switching the unit from the grounded connection to a floating reference. I did just this, and found that the sound quality has taken a leap forward. My Tacima conditioners have helped a lot, but the only really help on non-earthed devices, such as the TV, so I am guessing that a lot of the noise is coming from the house earthing connection. A balanced mains transformer should further improve matters.

My guess is that my Tacima conditioners are shunting the RF and other nasties down to the earth, and polluting that instead. As a result, they seem to be finding a path back to my hi-fi.

It's strange. I thought there was something that wasn't right somehow and I just couldn't put my finger on it, but it seems that isolating the Naim's electronics from the earth has made a big difference. :)

[Reid Malenfant]

You'll probably still find that it's connected via a capacitor (AC connection) which will help eliminate RF, it just won't be DC connected. Though i can't be sure of this as i don't know the kit.

Pick which sounds best & stick with it at the end of the day ;)

[colinB]

Isnt that the problem with conditioners they just dump interference back into the mains?
A real mains upgrade would be to have a perfect zero ground mains or am i talking s***e again.

[ursus262]

Isnt that the problem with conditioners they just dump interference back into the mains?
A real mains upgrade would be to have a perfect zero ground mains or am i talking s***e again.

Colin

You are talking perfect sense. I'm not sure, however, how you perform such an upgrade. I am assuming the mains earth is that which is connected to the electricity supplier's centre tap on it's three-phase system. If this is the case, the it isn't a proper earth in the technical sense. I had considered having an earth wire buried and connected to the house earth, but I don't know precisely how to do this.

[ursus262]

Oh, and the water pipe coming into the house is plastic, so no route to a proper earth there.

[Reid Malenfant]

I had considered having an earth wire buried and connected to the house earth, but I don't know precisely how to do this.
Unless you know precisely what you are doing then don't do anything ;)

The Neutral conductor is connected to real Earth back at the substation, you are correct about the 3 live phases. We just get fed one of them which results in 240V AC to Neutral :)

[colinB]

I just read an interesting thread by the guy behind Studio connections. He used to own Abbey road cables. His theory is to avoid the noise dumping ditch metal screens on mains cables and replace with a screen made of carbon.
Interesting :scratch:

[MCRU]

I just read an interesting thread by the guy behind Studio connections. He used to own Abbey road cables. His theory is to avoid the noise dumping ditch metal screens on mains cables and replace with a screen made of carbon.
Interesting :scratch:

I like these people who hint at messing about with mains, like reid said, leave well alone, the ground post in the garden is generally acceptable although not sure it actually makes your system sound any better.

[ursus262]

Examination of the manual indicates that the switch was in the wrong position all the time. It should have been set to the "floating" position. I thought there was something wrong with the sound my Naim was coming out with but couldn't quite put my finger on it.

It now performs as it should, and sounds absolutely wonderful.

My next step in the upgrade plan now, is to install a balanced mains transformer next to my hi-fi. With this, the earth consists of the centre tap of the transformer, so the equipment is completely isolated from the house earth. I understand that both poles are protected in case of fault currents.

[Reid Malenfant]

It wouldn't be isolated from the house Earth if a balanced transformer is wired correctly. The Earth on the secondary is connected to the house Earth & the two lives are balanced about that. The idea being that any common mode interference that is on the mains line is eliminated as much as possible if not completely ;)

[ursus262]

Well, quite :) Of course, one could overcome that problem by disconnecting the earth in the transformer plug, but that would just be bloody stupid

[ursus262]

I just read an interesting thread by the guy behind Studio connections. He used to own Abbey road cables. His theory is to avoid the noise dumping ditch metal screens on mains cables and replace with a screen made of carbon.
Interesting :scratch:

The purpose of that is that carbon, when subjected to electrical load, generates heat as its conductivity is lower than metal conductors. The RF Energy in the carbon braid is thus dissipated as heat.