Dedicated AV ring main

[Overdose]

I am soon going to add some more sockets in the living room, four doubles. The questions I have are...
[*]Would it be possible to incorporate some mains conditioning at this point, if it is needed, also what is available?[*]How do you know if you have 'dirty' or 'clean' mains?[*]Rather than add to the existing ring, would a dedicated ring or spur be more beneficial?Many thanks in advance for your thoughts.

 

[Anonymous]

I think you need just the one ring. One Ring to rule them all, One Ring to find them,
One Ring to bring them all and in the darkness bind them

 

[wireman]

Overdose:

I am soon going to add some more sockets in the living room, four doubles. The questions I have are...

[*]Would it be possible to incorporate some mains conditioning at this point, if it is needed, also what is available?
[*]How do you know if you have 'dirty' or 'clean' mains?
[*]Rather than add to the existing ring, would a dedicated ring or spur be more beneficial?

Many thanks in advance for your thoughts.

Answering your questions in reverse order, my thoughts would be:

3) A dedicated ring or spur (technically, a radial circuit rather than a spur) is always better for hi-fi/AV because most noise on an existing household circuit comes from a) other appliances connected to it and b) oxidised/loose connections which join the many existing sockets together as the ring snakes it's way around your house: Poor connections here also lead to increased impedance. A dedicated ring or radial gives you an unbroken length of wire direct from your consumer unit to your hi-fi with nothing that can generate noise sharing it (typically kitchen appliances, noisy heaters, table lamps etc) - other than maybe some of the hi-fi/AV components connected to it which can generate their own 'dirt' back onto the power line! In addition, a dedicated circuit gives you an opportunity to use wire which is much thicker than the standard 2.5mm cable - again, reducing impedance, and a much cleaner/robust earth connection (important!).

2) You don't unless you can measure it. An easy way to test for noise on a circuit is with a 'noise sniffer'. You can hire or buy them. But if you are going to run a dedicated circuit just for your hi-fi or AV equipment, it's best to do that first so you can test that circuit before deciding if 1) is necessary...

1) Yes, but it's likely that a dedicated circuit will in any case be much quieter than connecting your hi-fi/AV onto the normal household ring main. It's likely to be so much quieter that mains conditioning may be entirely superfluous, although spike/surge suppression is IMHO worth adding at minimal cost for peace of mind. This connects in parallel, is active only if there is a surge worth suppressing, and thus does not adversely affect the sound.

Hope that helps - I'm sure others here will have their own views...

 

[Overdose]

That's very helpful, many thanks. A dedicated ring it is, plenty of room left in the consumer unit.

One question though, how large a wire size will fit into standard three point sockets?

Bearing in mind two wires per terminal for the sockets on the ring, would 4.0mm2 be too big?

 

[wireman]

With MK sockets, you can fit 2 x 6mm or 1 x 10mm. If you're going to loop several sockets together and form a ring, 6mm cable with a 40amp MCB at the consumer unit is about as good as it gets.

 

[Overdose]

Then that is the way forward. Thanks again.

 

[wireman]

Electricians tip: When looping the sockets together, don't cut the cable... simply strip back the inner sheath an inch or so and fold the copper core back on itself, using pliers to form a tight crimp before inserting into the socket terminals. This way you have a continuous unbroken loop of cable. Over time, as the copper oxidises, there'll be less of an increase in impedance and decrease of performance. It can be a little bit tricky feeding the cable through from one socket to the next with 6mm, and a joint of two may be inevitable... but in my view it is worth trying to avoid joins in the cable if and where you can.

 

[Overdose]

That's a good tip. Cheers