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Does a separate mains spur for hifi make a difference?

Discussion in 'audio' started by junk01, Aug 14, 2015.

  1. Mike Reed

    Mike Reed pfm Member

    Good for you, Rob, but only one supply? Adding an earthing spike can only be done safely if you have a specific type of domestic earth bonding (TT, I believe). Generally this is older properties and rural ones. Fitting one to a PMC bonded house can potentially be lethal to houses sharing your phase, I understand (but I'm no expert). However, yes, it can reduce the impedance somewhat, potentially improving dynamics.

    DOES ANYONE READ THE POSTS, I WONDER? Two further mentions of SPURS (see my post 2) Dedicated hifi mains supplies ONLY INVOLVE RADIAL CIRCUITS.

    Main benefits from a separate supply, apart from the obvious reduction or elimination of interference and more conformity of supply whatever the time of day are IMPROVEMENT in DYNAMICS, which simply means better s.q. , transparency and sound-staging, etc. It can also be useful to have separate control of your kit's supply at the c.u.

    How much improvement will depend upon the quality of your installation and the general state of your mains supply (how many people share the phase, how far from sub-station and whether overhead or underground)
  2. Alexh

    Alexh pfm Member

    It would be the first thing I would attend to.

    A decent mains supply is a must if you do not want to hear clicks pops and bangs from the rest of the houses electric items.

    Also good if like me you are surrounded by wifi points.
  3. Mike Reed

    Mike Reed pfm Member

    Ah, we have an expert here I see !:) You're quite right, sticking a SPUR onto whatever existing circuit you wish is probably not going to make a scrap of beneficial difference
  4. Mike Reed

    Mike Reed pfm Member

    Interesting ! Not heard this before and have no knowledge of wifi; can it potentially cause problems on domestic ring mains?
  5. Hipper

    Hipper pfm Member

    As you can see experiences vary and so it seems that the only way to find out is to have it done. That's the view I took in my flat but it made no difference, except to give me a socket in a convenient place!

    I thought 10mm2 cable plus a Furutech double socket would be good. Firstly 10mm2 is apparently very difficult to work with because of its thickness so I was persuaded that 6mm2 will be just as good. That was no fun to work with but did get installed. The Furutech socket was a right pig to put the cables in. As each socket is separately wired it needed a separate cables to 'daisy chain' from the socket connected directly to the cable. This proved impossible to do with the 6mm2 cable and it seemed silly to do it with smaller cable so I ended up with only one working socket. The Furutech socket does seem a bit tighter but smoother when plugging in but frankly I might as well have used a standard socket.

    I should add that the circuit my hi-fi was on had nothing else working on it when I listened. The fridge is on the kitchen circuit and I don't even have a DVD player with a clock in use. That maybe why I heard no difference.

    If you do get a radial installed don't expect your electrician to understand what you are trying to do. Most likely he will say you are wasting money.

    If you have crud on your electricity, or the voltage varies significantly, you would be better off looking at mains treatment of some sort - main conditioners (including DC blockers), regenerators, or balanced mains. I went with a mains regenerator in the end and found it made a nice improvement, basically in noise reduction.

    As has been pointed out, late night listening improvements may well be more to do with ambient noise reductions then electricity supply. If you think that's the case you might consider (assuming you have typical double glazing) a third glass panel specifically installed to reduce noise. I live on a High Street and it made a big difference. I still hear the deeper sounds from buses, lorries, boy bloody racers etc., but it's still much better.
  6. finkaudio

    finkaudio pfm Member

    ....yes, I did. We analyzed the mains and found a lot of strange things going on during the day. But you just need a NAIM amp to find out if your main voltage got a DC component ......the transformer starts to hum like mad and stops after the DC component is low enough. Here in my listening room, it's really bad during the morning and always quiet in the evening or on a Saturday/Sunday. And you can easily see the Powerline system signals on your mains.
    Same problems also on shows...during the day even the voltage drops :mad:
  7. Ragaman

    Ragaman Mentalist

    I have a nait 3, I do get humming from the transformer, not loud but it is there, not a jot on my previous Rega or my current Rotel.

    I havn't dealt twith electrics for 20 years & unfortunately have no equipment nowadays to test this so I will keep an eye on my Naim to listen for a change in hum.
  8. LouisB

    LouisB pfm Member

    I've not heard any clicks, pops or noise from mains in my hi-fi, not for years since it stopped being strung together heath-robinson style.

    If I did, I might also wonder about a mains filter/conditioner first before re-wiring the house.
  9. finkaudio

    finkaudio pfm Member

    My Supercap and the 250 are the worst ones. It seems to be something that is more of a problem here in Germany. :confused:
  10. Mike Reed

    Mike Reed pfm Member

    Most of the Naim amplification kit I've had in the last generation has hummed from time to time, in different houses and geographical locations, including my current 552 power supply. Pretty much goes with Naim territory, but is of little or no consequence.

    Incidentally, my and others' experience would suggest that Naim kit benefits enormously from dedicated supplies.
  11. darrenyeats

    darrenyeats pfm Member

  12. Foot Tapper

    Foot Tapper Enjoy the music, not the format or kit

    I've posted my experience with the current system in this thread:
    "Hifi sounds better , shock."

    A dedicated radial supply has been beneficial for all 3 Naim systems that I have had over the years. However, Naim electronics seem to be quite sensitive to their mains supply. Other makes such as Bryston far less so.

    So, will it help? In some cases yes. In others no.
    But it is relatively inexpensive to do and will not make your system sound worse.

    Hope this helps, FT
  13. Steven Toy

    Steven Toy Accuphase newbie

    When mine was fitted we measured ground loop impedance before and after. Measured at the socket of one of the radial circuits it dropped from 0.6 ohms to 0.22 ohms iirc.

    One of the 4 sockets sounded quiter and more dynamic than the others. Perhaps it was a coincidence but the other three sockets measured 0.23 ohms.

    One of the more obvious effects of the new mains arrangement with 10 mm cable from the mains fuse to the dedicated consumer unit then 6 mm radial circuits to the sockets was being able to hear the source tape hiss for the first time on music CDs that were originally mastered and mixed on analogue tape.

    Given that my house does not have PME earthing the dedicated earth spikes are safe. I had 5 fitted in the garden linked in a star formation. This was done a week after the radial circuits and dedicated consumer unit were fitted. The effect was similar to a Naim preamp upgrade from, say, a NAC 202 to a NAC 252.

    All the work was carried out by a qualified spark.

    Three weeks later Central Networks upgraded the main fuse and fuse holder FOC from a 60 amp to a 100 amp fuse. They also inspected the installation and declared it safe in their view.

    This was back in February 2010.
  14. Mike Reed

    Mike Reed pfm Member

    Not sure I've read this correctly, Steven, but it sounds like you've bypassed the meter !!!! It should be tails (25mm2) from the meter to a junction box, then tails to both dedicated and domestic c.u. 10 or 6 mm2 t & e is normally only for the radials.

    Yes, a 100 amp main fuse (or 80/100 as mine was, for some reason) is needed if one is going to do it properly.
  15. Barrymagrec

    Barrymagrec pfm Member

    He couldn`t have bypassed the meter - nothing free ever sounds better.
  16. Mike Reed

    Mike Reed pfm Member

    I agree, and not only other makes may benefit less, different kit is improved in different measure.

    However (and again I agree with you), my contention is that if you've got some subjectively serious kit, you really should afford it a separate supply; there is no sonic downside with definite or potential upsides.

    One thing puzzles me though. If you're going to the trouble of installing radials, why then compromise the impedance and improvement by using plugs and sockets, let alone a fuse? The fuse is there to safeguard the cable (necessary in a ring) but a radial is already protected by its own MCB/RCBO. Certainly, plugs and sockets are handy (hard-wiring can be awkward), but a fuse....? The kit is protected by the case fuse. What else needs protecting?
  17. junk01

    junk01 pfm Member

    Mike Reed (#2): Spur vs Radial

    Mike, I know nothing about electrics, I just assumed that it was possible to run a single cable from the CU to a socket. I stand corrected.

  18. junk01

    junk01 pfm Member

    Del monaco (#3);
    Basil (#4);
    Ynwoan (#5);
    Ragaman (#7)

    No difference vs some difference

    It certainly seems like that this is not a cut and dried thing and that doing a "turn everything else off on the ring" test is worth doing several times before committing to any expenditure.

    As always with hifi, the subjective element exceeds the objective and what's happening between my ears seems a greater determinate than anything else.

  19. junk01

    junk01 pfm Member

    Whatsisnaim (#9);
    finkaudio (#26);
    Mike Reed (#30);
    Foot Tapper (#32)

    Good for Naim setups?

    It seems that Naim kit has a predisposition to hum and that Naim owners seem to feel that a dedicated supply worked for them. This is of particular interest to me as my system is olive Naim.

    However, I'm unclear whether the (transformer?) mechanical hum is anything other than an irritant. Does it affect the sound quality or is it incidental?

    If it is assumed that this hum affects sound quality is there any comprehensible-to-a-thicko-layman-like-me type of explanation?

  20. finkaudio

    finkaudio pfm Member

    Transformers don't like DC - makes them noisy. Not a special NAIM thing, but it happens only on large transformers and they are a NAIM thing :p

    Something to read:

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