mains query...

Discussion in 'Hi-Fi and General Audio' started by mr cat, Apr 11, 2005.

  1. mr cat

    wadia-miester Mighty Rearranger

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    OK, its pretty well known and I have mentioned it on HFC once :eek:
    A 1v dc offset has been festering around for quite a while now, so maybe a diode and cap network (600V min I would recommend) might help here, has a quite pleasant effect, most cost effective too :)
    As for the other stuff, maybe as your more open minded that I first thought :eek: perhaps you would like to whitness some first hand :) Wm
     
    wadia-miester, Apr 11, 2005
    #21
  2. mr cat

    mosfet

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    1v DC offset? No I haven't looked for that but I shall! :)

    Seems a little high, maybe a few hundred millivolts but still sufficient to cause problems for a toroidal transformer. And I do remember seeing a circuit diagram somewhere for an asymmetric DC filter..

    Open-minded scepticism is always best. ;) :D
     
    mosfet, Apr 11, 2005
    #22
  3. mr cat

    ListeningEar

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    ...or,...the first rule of Quality System management is,..'question everything'. ;)
     
    ListeningEar, Apr 12, 2005
    #23
  4. mr cat

    ListeningEar

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    Ahhh 'mosfet', don't start getting me all worried now :p

    To be honest, since moving into my current home last July we have been making some pretty drastic modifications to the floor-plan so the audio system has been packed away.

    Our home is only about 55 years old but it is still a solid brick home without any stud partitions at all ;) This has made re-wiring quite a challenge. The interesting 'feature' is that it only has one ring-main so to play safe I installed the previously mentioned filter sockets by way of experiment. I wanted to protect all my IT equipment for sure so that was my main reason for installing the filtered sockets, but I thought, prior to actually splitting the ring main let me try a filtered socket at the location where the audio system will sit.

    As we just about to have new carpets fitted in the lounge this means that I will be able to run my own little tests to compare the following:

    1. With filtered sockets and Eichmann power cable
    2. Without filtered sockets and with Eichmann
    3. Without any power cable modifications
    4. Same as above but post ring-main split

    I will have to conduct numerous listening tests (what a shame), but hopefully will be able to come out of it with a sonically pleasing result.

    NOTE: Even though we have just one ring-main the local utility checks have verified that we do not actually need to split the ring as the circuit has been modified to current IEE wiring regulations with appropriate RCB's,...or is it RCD's these days?!?!

    OK, time to stop rattling on...
     
    ListeningEar, Apr 12, 2005
    #24
  5. mr cat

    mosfet

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    When all is said and done this of course is all that matters LE.

    Out of interest do you know what's inside the 'blue box' on the Eichmann power cord? The website says there are no current limiting “capacitors or other electronic components†so perhaps a big whackin ferrite?

    Sceptical? When I read phrases like “fractal resonance control technology†what do you expect! :eek: The Eichmann bullet plugs are a rather neat design tho'.



    Tony

    DC blocking circuit
    http://www.sjostromaudio.com/hifi_files/qrp/dct01r0schema_p1.pdf

    http://home.swipnet.se/~w-50719/hifi/index.html
     
    mosfet, Apr 12, 2005
    #25
  6. mr cat

    wadia-miester Mighty Rearranger

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    Richard,
    Fear not built the odd one or 2 in the last few years, but thanks.
    Our mains boxs have the ability to screen this too as a matter of coarse.
    Prehaps you would be up for a visit maybe with some of your open minded sceptisum? Wm
     
    wadia-miester, Apr 12, 2005
    #26
  7. mr cat

    ListeningEar

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    ListeningEar, Apr 12, 2005
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  8. mr cat

    mosfet

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    Tony, you have PM.

    LE thanks for taking the time to respond.

    I don't quite see the connection between fractal mathematics and power cable design – not that I know an awful lot about fractal mathematics other than those infinitely geometric models that fractal equations produce.

    Aluminum alloy does indeed have high internal damping owing to low mass and high rigidity so there may be something there that isn't immediately obvious..

    But does this mean we can expect loudspeaker cable based on chaos theory any time soon! (remember where you read it first!) :D
     
    mosfet, Apr 12, 2005
    #28
  9. mr cat

    peranders More is better

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    peranders, Apr 14, 2005
    #29
  10. mr cat

    penance Arrogant Cock

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    Hi Peranders,
    Good to see you here :)
     
    penance, Apr 14, 2005
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  11. mr cat

    mosfet

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    Hi P-A

    Thanks for making the circuit schematic for the DC trap available.

    On a similar point does anyone have any comments on this modification?


    “I learned about a tweak that allegedly could make some cheap DVD and CD players sound much better: putting two 0.47UF 600V Auricaps across the hot/neutral wires in the power input of the player is supposed to filter all sorts of crud out of the power. Auricaps are pretty expensive, so I tried it first with similar A/C power rated caps, but that didn't do anything noticeable.â€Â

    “So I put them [the Auricaps] in (behind the fuse, so they don't fail and catch fire while the unit is unattended), powered up and sat back to listen. It took a while before I was able to lift my jaw off the floor... AMAZING detail, sound stage definition up a full level of magnitude.â€Â


    There's little unusual about placing a capacitor across live and neutral to add some parallel HF filtering – but are Auricaps (or any other high quality metallised polypropylene cap) better than a standard X2 cap in this application or is this wishful audiophile thinking?
     
    mosfet, Apr 14, 2005
    #31
  12. mr cat

    Graham C

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    Yes I do. People can do what the hell they want to themselves and pay the consequences if sh*t happens, but I wouldnt recommend to anyone else that they start fitting components in the mains that are not designed for the purpose. You have not even told us if the quote refers to 110V acrms or 230 acrms?

    Answer yourself this: Can you stand in the witness box, under cross examination, and explain to Judge Judy why you chose to use inappropriate [perhaps illegal, if you were selling it] components? If not, leave the bloody thing alone. Build some bigger speakers
     
    Graham C, Apr 14, 2005
    #32
  13. mr cat

    penance Arrogant Cock

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    ^^ What graham said, x and y class caps are designed for mid voltage Ac use, most plastic caps are not.
    if you decide to try it, it as your own risk.
     
    penance, Apr 14, 2005
    #33
  14. mr cat

    mosfet

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    Whooa hold on!!

    I'm not recommending this modification to anyone – clearly there are obvious safety implications of using non class X rated caps in this fashion and this I'm patently aware of. Merely I was asking for critique from those who I assumed would already be aware of such considerations.

    GrahamC

    Go read my contribution to the 'TNT audio powercord' thread before putting your barristers wig on!
     
    mosfet, Apr 14, 2005
    #34
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