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Dedicated mains: 1 or 2 lines?

Discussion in 'audio' started by Heckyman, Nov 14, 2019.

  1. Heckyman

    Heckyman pfm Member

    Finally have the opportunity to install a dedicated radial and am wondering if it’s a good idea to install a second one while I’m at it? I could then plug everything into the wall, cut out my mains block and save a mains lead.

    My system is streamer, DAC, 50W integrated amp (router is on other side of room connected via Ethernet and would stay on the existing ring)

    Any tips from experienced folk most welcome!
  2. Chops54

    Chops54 pfm Member

    Depends how much kit you have and how far you want to go. If you're pulling one cable in it can be just as easy to pull two in. I have two radials running from a separate consumer unit to my hifi. Each feeds an eight way mains block. Anything with a motor or wall wart goes in one block, amplifiers and such in the other. The router is fed from the upstairs ring main.
  3. chartz

    chartz pfm Member

    When I did my electricity - 20 years ago - I drew a second line. Not because I expected better sound of course, that’s impossible, but because I wanted to get rid of power blocks.
    I therefore installed 9 new sockets in the wall around my hi-fi and computer stuff (dedicated room like you).

    Not near enough in the end, I have to use power blocks!
  4. uncl_nigel

    uncl_nigel pfm Member

    I had two lines installed 20 years ago and generally only use one... Both are radials as rings are illega here in France.

    Rule number one about sockets: if you want to avoid using power blocks, liberally estimate the number of outlets needed and then double it and add a few more for good measure. I applied this to a kitchen we had in Orléans and five years later every outlet was occupied so there was nowhere to plug in the egg beater :)
  5. stevec67

    stevec67 pfm Member

    I think there's a lot of mileage in using conduit like they do in offices. Then you can add, remove, and move sockets easily without changing plasterwork. Just pop the cover and wire one in. When you move or change the layout you can return it to normal without leaving rows of ugly unused sockets.
  6. poco a poco

    poco a poco pfm Member

    When had our house retired while building an extension I had our electrician put in a dedicated radial with shielded mains cable I wish now I had put in two. As much for positioning sockets and wires for less visibility than possible further sound improvements over using a mains block. Ethernet over mains is on a separate ring main in the same room.

    If in doubt and it does not put the cost up to much go for two.
  7. Chops54

    Chops54 pfm Member

    Dado trunking?
  8. stevec67

    stevec67 pfm Member

    That sort of thing, yes, or the same that runs down a skirting.
  9. Heckyman

    Heckyman pfm Member

    Good ideas so far, thanks. I was wondering, can there be any actual detriment to SQ by splitting the amp and source? I understood grounding is important, so in this case everything just gets grounded at the CU rather than the distribution block, right?
  10. Chops54

    Chops54 pfm Member

    Safety earth connection and signal earth are not the same thing though they may be connected together at some point in the system. Safety earth really should not be used for any other purpose and with that in mind I see no reason for star grounding of the safety earth.
    Julf likes this.
  11. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    Everything here getting power from a 4 extension blocks, all 4 outlet, all from the likes of B&Q, Aldi etc. No need for anything "better".
  12. Richard Lines

    Richard Lines pfm Member

    Good Afternoon All,

    I would go with advice re thinking how many sockets you need then doubling it. When we were rebuilding the upstairs of our 1859 farmhouse and ripping out the woodworm riddled lath and plaster, installing insulation etc. I installed 5off double sockets on the landing where it was intended to locate the computer gear. We still need a 6 way block under the desk and when updating the franking machine (can't get the wireless side to work) I have to lug the machine upstairs once a month and plug it in c/w its own modem so have to use another two sockets.

    I ran a dedicated radial to the Hi-Fi room as part of that refurbishment project and there was a fair amount of umming and aching as to whether to fit at least 6 double sockets so everything could be plugged directly into the wall. In the end I connected just the one double socket to the dedicated line and run 2off 6 way blocks off this.


  13. Chops54

    Chops54 pfm Member

    Also a lot of kit made today is double insulated so has no safety earth to worry about.
  14. Heckyman

    Heckyman pfm Member

    Yes, I believe I was thinking more about "signal ground (earth?)", but I don't properly understand what that is. I have some notion that the signal grounds from all components meet in the distribution block...i.e. could the block could be performing some worthwhile grounding function? Or is it just an unnecessary obstruction? Or does it depend on the design of the kit?

    An electrician will be doing the actual installation, I just need to fill him in on the audiophile aspects ;-)
  15. Heckyman

    Heckyman pfm Member

    ...my electrician says the earthing system is TNCS. He wasn't that impressed with the earth wire in the CU as it's quite an old installation. Whether this has any relevance at all to what I want to achieve was what I was hoping to get advice on from the audiophile electricians amongst us!
  16. Ian G

    Ian G Active Member

    I don't really see the point of two radials in the same room if they are both only doing hifi. If one may be used for electric heating then it makes sense as the heater will cause done voltage drop when it's on. If this isn't the case install a single radial and connect as many sockets as required within reason.
    How far from the consumer unit is the room as it may be prudent to run in 4mm with a 25a rcbo or MCB depending on existing installation.
  17. Ian G

    Ian G Active Member

    Some not done
  18. chartz

    chartz pfm Member

    No relevance. Hi-fi boffin and electrician speaking.
    Arkless Electronics and Julf like this.
  19. Heckyman

    Heckyman pfm Member

    The main idea of 2 lines was to separate the high current amp from low current sources that might benefit from filtering etc. which could squash the dynamics of the amp. Or perhaps use the second line for wall-warts as someone posted above. Or musical instrument amps.

    CU is in the cellar, almost under the room so the run would be quite short.
  20. Mike Reed

    Mike Reed pfm Member

    Unless you want to install an earth spike as many have.

    Heckyman, I know your system is relatively simple, but do you really know if it'll be the same in, say, five or ten years? Take the advice above, but don't stop at two radials*. Neither should you use the existing domestic c.u., but have a separate one with extra capacity.

    * unless you can easily route more in the future.

    You're spending £X; future-proofing it will add little and potentially save a lot in the future. Use 6mm2 T & E (one for amplification ; one or more for source(s)). If you must have sockets, make them unswitched. individual RCBOs are preferable in the c.u., though more pricey. Have had at least 5 radial circuit installations in many rooms/houses since the eighties and domestic electrics has advanced a great deal in terms of convenience and safety over that period since.

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