Can I ask who has had a separate mains spur made for their Naim?

My understanding is that by isolating the Hifi supply from the rest of the house electronics you are thereby isolating it from interference caused by the rest of your domestic items - computers, fridges, lights, washing machines etc etc

Certainly I found that a spur helped here to some degree - still get transformer hum though

Expect to pay £2-3 hundred for a separate consumer unit, cabling, sockets, earth spike etc.

A spur or dedicated ring main should improve the sound of your Hi-Fi system plugged into it, though some would dispute this.

You can do this yourself but I believe there is now legislation in place which means you have to get it checked out by a qualified electrician who will then issue a certificate of compliance.

I don't believe that earth spikes are used anymore. Bonding the earth connection to the outer armouring of the supply cable is the way it has been done for many years.

when i put my system on its own mains, i heard these benefits :

- lower noise floor (silky black background)

- improvement in PRAT

- more "color" to the sound (overtones)

- more dynamic range, especially microdynamics.

What the electrician does [should do] is provide you with a set of sockets connected back to your fuse box ...

Normal wiring is designed for 13amp plugs but lots of people who get dedicted hi-fi wiring get wiring suitable for an electric cooker [i.e. much thicker wiring] ...

James H.

I found with mine it gave me more music, more insight, better flow with better consistency aswell as an absence of any annoying clicks coming from other nasties(ones already mentioned) in the mains.

quote:

Originally posted by Consciousmess:
Hi,

I had to ask this question as I have the intention of doing this myself and may start to call round local electricians for quotes. However, I have been told by a colleague (who is proficient in such matters) that this will make no difference to the sound as the local transformers in local powerstations do all the smoothing necessary for domestic supplies.

Maybe he can explain why the line voltage here can typically go from about 218V to 240V, up and down in the period of a day? Or does he think that a 10% swing counts as "smooth"?

quote:

However, I have been told by a colleague (who is proficient in such matters) that this will make no difference to the sound as the local transformers in local powerstations do all the smoothing necessary for domestic supplies.

Funny how people who claim to be proficient in such matters namely electricians, engineers and scientists keep telling us we won't hear a difference installing a separate spur or using a different mains cable.

I would ignore your colleague and go ahead - there has been much discussion on this Forum on the benefits of a separate mains spur.

regards,
mat

I have a dedicated hifi circuit - technically it's a radial rather than a spur, but the terms tend to get mixed up. A radial circuit is a single cable that runs all the way back to the consumer unit. A spur is a single cable that runs back to a junction on a ring circuit. I choose to fit a dedicated consumer unit as well to get the maximum benefit.

The details of the job are:

Split the meter tails (thick wires from the meter) using a Henley block. This gives 2 sets of wires, one goes to the original consumer unit, the other set to the new hifi consumer unit. An earth connection is also made from the new consumer unit back to the supply cut-out. The radial itself is a thick twin and earth cable - 6mm or 10mm squared conductors - that runs from the hifi wall socket back to the consumer unit. In the consumer unit some kind of over current protection (fuse or mcb) and an RCD connects the radial to the internal wiring, then via an isolating switch to the meter tails. Real purists will debate the sound quality of different consumer units and whether MCBs and RCDs affect the sound. The earths are also connected together in the consumer unit. All the above is notifiable to the local building control dept and must be done according to buiding regs - BS7671 is the relevent standard, but this is usually called 'Part P'

One all this is done you have a high quality connection with as few joins as possible between the hifi and the mains entering your house. Benefits include -

Relative isolation from all the other kit in your house - avoids clicks, pops and other nasties.
Low impedance earth back to the supply cut-out.

It does not however give you any help if the mains supply to your property is 'noisy'. This depends on who else is connected to the feed from your local sub-station. Light industry, anything with big electric moters etc. pollute mains...

Unless you really know what you are doing, have all the right test gear and are prepared to negotiate with your local building control dept. get a qualified sparky to do this!!!

And finally, expect this thread to be moved to the Padded Cell at mains related threads are not usually tolerated here...

Yep, Mine is on a separate spur, part of a full house rewire when I moved in, so can't say if it improved things.

But, I never get interference from things in other part of the house, and the cost was swallowed up in the 'essential rewire the mortgage company MADE ME have

Mains measures at 246v almost all the time!

Hi cap transformer hums nicely on that thanks.

i have a 60amp dedicated mains spur and it works wonders. i have 243v in my house and its 90% constant. the earthing is also done correctly. infact the house was rewired about 10 years ago to a vey high standard. each room has its own sockets on a respective RCB, all the lights on each floor are on their own RCB (3.5 floors). all was done with crabtree sockets but i have MK hospital grade products throughout on the dedicate hifi spur.

i still get a small amout of hum from time to time but i expect its the local grid thats causing this.

a great upgrade and one of the best VFM things you can do. Mike summed up the improvements nicely, it was quite a revelation.

Get some quotes and get it done.

quote:

Originally posted by mikeeschman:
when i put my system on its own mains, i heard these benefits :

- lower noise floor (silky black background)

- improvement in PRAT

- more "color" to the sound (overtones)

- more dynamic range, especially microdynamics.

My experience exactly. Well worth doing.

Conciousmess,

I recently had a seperate hi-fi spur (more correctly a radial circuit) installed in the bungalow we've just moved to. It's made from 10mm sq. cable, so much heavier guage than that used for normal socket ring mains. It also has seperate tails back to the electricity meter. This keeps it as seperate as it is possible to achieve from the rest of the supply to the property. (the meter is as far back as you can go, beyond that the wiring is the property of your electricity supply company and it is illegal to tamper with it). My spur has a seperate consumer unit with just an ON/OFF switch and a 30A cartridge fuse. There is no RCD protection, which I reasoned could degrade the supply. My electrician tells me that by law, normally all sockets in a domestic property MUST have RCD protection. However, there is apparently special dispensation available, normally used by hospitals and the like, whereby some sockets (eg. those supplying power to life support systems), can be left without an RCD in circuit as the risk of power loss through accidental tripping is more serious than the risk of electrocution. Such sockets must, by law, be labelled "NO RCD PROTECTION". So this is how my double unswitched Crabtree socket is labelled! By isolating the hi-fi supply from the rest of the property you are avoiding any mains interference from other appliances you may have. A seperate spur also allows you to use heavier guage cable resulting in reduced impedance. Both of these factors lead to improvements in sound - typically better dynamics, lower noise floor, simply better music! The magnitude of the effects can be variable. It also has to be said that a small number of people have reported that it sounds worse than a ring main! IMO it's well worth getting done - the vast majority of people (including myself) report very worthwhile benefits. Unless you have appropriate training it is definitely NOT a DIY job. In any case, it must be certified by a registered electrician, usually this will be the person carrying out the work.

Peter

Choice of consumer unit for the never ending quest for mains perfection. 45 or 60 amp rated consumer units are limiting the source right at the beginning, not only because of the switch, but also the joins and use of thinner copper in construction. 100amp is the way to go.

It is written in the forum rules, you can not post here if your HIFI is not on a dedicated line. THIS IS MANDATORY.

Over here in the Colonies, we call it a "dedicated circuit" and we simply run a length of #12 Romex back to the breaker box, find an empty 20 amp breaker and hook it up. Those of us that are fairly clever can do it without hiring a "sparky", and avoid those pesky regulatory agencies that would want us to get a permit.

Tom

Romex #10
and a 20 amp outlet with a 20 amp breaker.

I used twisted #10-3 + ground. Three circuits on 120V 20 Amp breakers, on same side of the bus. Only the black wire is hot, and the others are all common grounded at ground bus bar. The service is 200 Amps @ 120V.

Compared to the #12 shared circuit I had before, this was a vast improvement. As reported above, a quieter background, with the music somehow "smoother" (in a good way) better pace, and somehow more whole and coherent.

I just went for it - I did not compare different wire, etc., so I can only vouch for the before and after. It is a major upgrade for little money.

I highly recommend it.


Charlie

I recommend Romex over twisted, sounds more dynamic. And it should be quite loose into the staples if you use them.

Its amazing what you can hear on a "hungaroring" quality mains feed. Even TheGods@Naim were surprised :-)

Just remind me again Jon, did the MD of Naim comment on your mains installation as being like the race circuit in Hungary?

I believe the circuit is full of twists and kinks, and is pretty dusty. I think it was Paul's polite way of saying please sort it out.

quote:

Originally posted by count.d:
Just remind me again Jon, did the MD of Naim comment on your mains installation as being like the race circuit in Hungary?

I believe the circuit is full of twists and kinks, and is pretty dusty. I think it was Paul's polite way of saying please sort it out.

Like a lot of mains-related things you quite simply will not the type or scale of improvement you are going to get until you have tried it.

For me the improvements were perceptible but not massive. Improvements from a Powerigel, for example, were bigger.


Cheers

Mike

Thanks for the feedback, guys!

I've printed this out for my reference, but I do need to clarify one thing (you are going to think I am a dunderhead in asking this, but electricity isn't my field!)....

Will I need to pull all the carpet up to connect the hifi mains socket (in my lounge where my Naim is connected) to the new spur fitted next to the fuse box under the stairs??

Do I do this, or does the electrician work out which plug socket each fuse under the stairs is connected to (with some instrument) and then attaches the separate spur to this??

I'm sorry for appearing slow here, but Id be more than grateful for your further tips!!

Regards,

Jon

When I moved in here, I had a separate spur installed by a professional electrician. It was before the system had been set up, so I can't report before and after. I do find however that the presence of absence of electrical equipment plugged into the other circuits in the house has no effect on the system's sound, except when the washing machine is on, where I do get some intermittent hum from one of more of the boxes (it's an active system, so more boxes).