Can I ask who has had a separate mains spur made for their Naim?
Posted by: Consciousmess on 06 February 2009
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.
I really am curious who here has had a spur done, and what the benefits are???
Can I also ask why there are benefits?
If possible could someone also explain what the electrician actually does?
Id be really grateful for your posts!!
Jon
Posted on: 07 February 2009 by DaveBk
Jon,
I'll try to explain further... Most houses are wired up using what is called a ring main. The ring starts at the consumer unit (fuse box), and then connects in turn to each socket in a loop (ring) around the house before finally heading back to the consumer unit. Both ends of the ring connect to a single fuse, or in newer houses an electrical device called a miniture curcuit breaker (mcb). Most houses have a ring main serving the downstairs sockets, and another serving the upstairs. Some properties may have a ring dedicted to the kitchen as this is usually where the high power devices are situated - toasters, kettles, dishwashers etc.
Your hifi in the lounge is most probably connected to the downstairs ring. To wire in a dedicated radial (spur..) you will need a new socket fitted in the wall and a cable run back to the consumer unit under the stairs. The best route for the cable depends on the construction of your house. If you have solid concrete floors running the cable under these will be a major job, a more likely route will be to cut a channel in the wall and run the cable between the ceiling and the floor above.
So regarding the carpet, this may be the least of your problems - channelling out the wall, lifting the carpet and floorboards above, and then replastering, painting etc. can all be part of the job!
It would be possible to run the new cable in a conduit up the wall, but this looks a bit naff in my view, and I'd never get away with it with my wife!!
Depending on the layout of your house it's quite a big job.
(and surprise surprise, this thread is now in the Padded Cell
)
Posted on: 08 February 2009 by Milo Tweenie
It’s worth thinking laterally about cable routing; sometimes the simplest route is armoured cable run round the outside the house.
Posted on: 08 February 2009 by Don.E
Can you wire up TWO unswitched double sockets to a dedicated spur(radial) without any loss of performance? Or do you have to run a separate cable to each with its own conection in the consumer unit via fuse/RCB?
Don
Posted on: 08 February 2009 by Consciousmess
quote:
Jon,
I'll try to explain further... Most houses are wired up using what is called a ring main. The ring starts at the consumer unit (fuse box), and then connects in turn to each socket in a loop (ring) around the house before finally heading back to the consumer unit. Both ends of the ring connect to a single fuse, or in newer houses an electrical device called a miniture curcuit breaker (mcb). Most houses have a ring main serving the downstairs sockets, and another serving the upstairs. Some properties may have a ring dedicted to the kitchen as this is usually where the high power devices are situated - toasters, kettles, dishwashers etc.
Your hifi in the lounge is most probably connected to the downstairs ring. To wire in a dedicated radial (spur..) you will need a new socket fitted in the wall and a cable run back to the consumer unit under the stairs. The best route for the cable depends on the construction of your house. If you have solid concrete floors running the cable under these will be a major job, a more likely route will be to cut a channel in the wall and run the cable between the ceiling and the floor above.
So regarding the carpet, this may be the least of your problems - channelling out the wall, lifting the carpet and floorboards above, and then replastering, painting etc. can all be part of the job!
It would be possible to run the new cable in a conduit up the wall, but this looks a bit naff in my view, and I'd never get away with it with my wife!!
Depending on the layout of your house it's quite a big job.
(and surprise surprise, this thread is now in the Padded Cell )
Dave,
Many thanks again, you've clarified that for me!! I feared that may be so as we have recently had the lounge freshly plastered and my partner probably wont take well to me hacking up the wall!!
I am still going to look at doing this...
Thanks again,
Jon
Posted on: 08 February 2009 by KennethDavidson
Just to add my tupenceworth.
A few weeks ago I asked my electrician to add a dedicated spur for our system. We have had a constant transformer hum from both the CD5 and the FC2. Before he cut any walls, he wired a 30 amp cable (the largest he said he could fit) into the consumer unit and unrolled it into the living-room. We listened to the change between the standard socket and the test spur - nothing!!
The hum hummed happily whether from the existing socket or from the new cable. We didn't proceed with that idea, and my bill was smaller as a result.
Maybe the advice is - try before you buy - it might not make any difference.
Posted on: 08 February 2009 by DaveBk
I'm not convinced that dedicated radials, spurs or whatever help with transformer hum. Transformers hum more when the core gets saturated - either due to an overvoltage or a dc offset on the mains. The transformer on my Supercap hums away to itself sometimes - I'll try to remember to check the mains volatge when its particularly loud to see if it corrolates with higher than usual voltage.
Posted on: 08 February 2009 by rega1
quote:
Originally posted by gary1 (US):
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.
I upgraded in december myself after seeing Gary1(us)'s set up. It is a rather nice upgrade. When the fridge kicks on, or the furnace starts up, there is no affect on my sound, it makes for nice music presentation, constant if you will.
rega1
Posted on: 09 February 2009 by count.d
quote:
Originally posted by Don.E:
Can you wire up TWO unswitched double sockets to a dedicated spur(radial) without any loss of performance? Or do you have to run a separate cable to each with its own conection in the consumer unit via fuse/RCB?
Don
Don, yes of course you can. imo this is the best way to do it and is what I've done. Use 10mm2 cable for the spur and also to daisy chain the two sockets together, which is possible, but pretty difficult.
The earth should not be joined inside the consumer unit, but taken directly (uncut) to the earth terminal on the main house supply box.
I consider joins, contacts and switches to be the biggest culprits of poor mains supply. When I first had a separate consumer unit (60amp) installed, I just left the electrician to do his job to fit it straight from the box. After a year, I bought a 100amp consumer unit to see if the higher rated switch would provide a better contact and hence cleaner flow. Before the new consumer unit was installed this time, I completely stripped every component and replaced steel screws with longer threaded solid brass ones for better conductivity, checked and tightened all joins, banged the rivets to tighten the joins (one was very slightly loose) and cleaned all contact areas with acetone. The result was an instant success. My three wall sockets had the same treatment. You cannot rely on the manufacturer of consumer units and sockets to build a perfect product fit for expensive hifi. Unlike Naim products which get rigidly tested for quality before leaving the factory, consumer units and sockets are not. One loose rivet, screw or dirty connection in the mains can destroy the sound without you knowing it.
Posted on: 09 February 2009 by 555
Have you considered providing this service as a new career count.d?
Posted on: 09 February 2009 by count.d
quote:
Originally posted by 555:
Have you considered providing this service as a new career count.d?
In this economic climate 555, I'm starting to.
Posted on: 09 February 2009 by BigH47
Would you think there would be any thing to be gained by soldering or even brazing the joints in the consumer boxes?
Posted on: 09 February 2009 by count.d
Very good question BigH. I've never read definitive advice on the subject of mains, so most results come from trial and error. We solder speaker cables, but not mains cables! Why? I would have thought a brazed brass/copper joint would be better than a riveted one, but I've not tried it.
When you look at exactly how a typical consumer unit switch works (or any riveted joint), you'll realise that the importance of cable diameter, fuse rating, etc... start to become a little less significant. The switch is just four little copper bumps being pushed by springs to contact a copper strip... and the whole hifi works through this!
How many joints does a multiple spur have? Yuk!
Quality and simplicity of mains installation has always been my ideal.
Posted on: 10 February 2009 by 555
quote:
I'm starting to.
Unlike my usual posts I wasn't being facetious.
Seems to me there could be some milage in such a service count.d.
Posted on: 10 February 2009 by roo
quote:
I'll try to remember to check the mains volatge when its particularly loud to see if it corrolates with higher than usual voltage.
My voltage measures around the 250V mark and that probably explains why my 250/2, SUPERCAP and XPS2 all hum quite noticeably. The 250/2 is the worst culprit.
I had a two radials installed recently and found that they did about 1/3 of what a PowerLine does to the sound. The spurs were a great upgrade considering the modest cost. If you've spent thousands on Naim kit it really is worth spending a little bit extra on a spur and some PowerLine cables. The only thing you may need to watch out for is using a C curve MCB instead of a B curve as the inrush currents used to cause my B16 MCB to trip. As always consult your electrician. I know some forum members advise using a 32A MCB but my electrician only wanted to go as far as C20 on safety grounds.
Posted on: 10 February 2009 by count.d
quote:
I know some forum members advise using a 32A MCB but my electrician only wanted to go as far as C20 on safety grounds.
?. 10mm2 and 6mm2 cables generally have a rating of 64amps and 40amps respectively and this is what the fuse in the consumer box protects. If your spur is 6mm2, a 20amp MCB seems ott protection.
Posted on: 10 February 2009 by roo
As well as protecting the circuit the MCB is also protecting you from from electric shock where current flows through a person from phase to neutral or phase to phase. I'm just taking advice from my electrician and I'd figure he knows best since he is qualified. Better safe than sorry in my book even if there is an extra 1% to be had from my Hi-Fi.
Posted on: 10 February 2009 by DaveBk
The MCB will do nothing to protect you! You're dead with a few tens of milliamps. As count.d says the MCB protects the wiring from overheating if there is a fault. You are protected by the RCD which will trip if there is a fault current to earth.
Posted on: 10 February 2009 by rough edges
quote:
Originally posted by count.d:
quote:
I know some forum members advise using a 32A MCB but my electrician only wanted to go as far as C20 on safety grounds.
?. 10mm2 and 6mm2 cables generally have a rating of 64amps and 40amps respectively and this is what the fuse in the consumer box protects. If your spur is 6mm2, a 20amp MCB seems ott protection.
Hi. The fuse in the consumer unit protects everything on the circuit that it feeds. Thus, it not only protects the wire, but also the receptacle(s) and whatever is plugged into that circuit. In the event that one is using a 20 amp receptacle, the maximum rating of the fuse on that circuit is 20 amps. Presumably, that's what the electrician was dealing with here.
Best
BB
