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Thread: The truth about interconnects?

  1. #1
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    Default The truth about interconnects?

    This thread is concerned with audio interconnect cables.

  2. #2
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    Default Directional cables? How? Why?

    I suppose that all the discussions on the speaker cables subject, applies here as well. All that is really needed is a length of good thickness copper wire. Mechanically, the interconnect has to also allow for a good quality, robust electrical connection to be made, so there need to be good quality end connectors at both ends of said wire. All else is probably in the unheard/unverifiable category, unless there is some impedance matching circuitry in the interconnect, in which case the comparison isn't apples and oranges anymore.

    A question to which I suspect I know the answer - most interconnects are sold on the basis that they are directional, and there is a specific end for the source and the other then for the signal receiver, like a power amplifier, so that the interconnect is aligned with the signal/current path. Is this just clever marketing? Because to my knowledge, electricity doesn't care a jot about directionality?

  3. #3
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    Default Interconnects may require a shroud?

    Just a suggestion. I've no actual knowledge. But I believe an interconnect differs from power leads and speaker cables in that they transmit very low-level signals, and are therefore subject to picking up interference that can actually be audible. So I believe an interconnect ought to be designed with some sort of shroud, like aerial coax, to block most of this.

    I guess any old coax with suitable plugs would do.

    The directionality thing might be due to the manufacturer's intention to ground only one end of the shroud (it's supposed to be the amplifier end), when the return signal flows through its own wire rather than the shroud itself, as is the case with ordinary coax.
    Ben from UK. Harbeth P3ESR owner.

  4. #4
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    Default Cable directionality?

    Yes, Ben, you are correct about directionality being, in most cases, determined by the end of the interconnect where the shield is joined to the signal common. It isn't that the cables won't work if installed in the opposite direction, in fact, it might be desirable to so in certain applications. If you have a system with only one 3 wire component; lets say that component is your preamp. You could arrange the interconnects such that all the ends with shield and signal common bonded together terminate at the preamp. This would minimize your chances for group loops and the resulting hum caused by them. If you have all double insulated (2 wire) components, or a mixture, you would just follow the recommended directionality. The idea is to ground the shield at the source, and therefore, away from the signal's intended destination.

    That said, there is another theory espoused by marketers saying that the direction that a wire is drawn in, which would be opposite the direction that it GOES ON to the spool and the same as the direction is COMES OFF the spool is audibly superior. PS Audio is one large cable manufacturer that makes this claim. Most bulk cables have directional arrows as well. In a DIY situation; the user has a choice of which end to bond the shield, or both, or neither for that matter. Perhaps the arrow is just there as a suggestion or to promote consistency. To my thinking, all audio cables (except for umbilical from separate power supplies) carry alternating current. This is true whether you're talking about power cables, interconnects, or speaker cables. Any directionality would have to be seen as "Diodicity" or the tendency for a conductor to pass current in one direction while attenuating it in the opposite direction. This would be a fatal flaw for any audio cable.

  5. #5
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    Default Cable directionality and change in sound quality?

    Quote Originally Posted by Diminish View Post
    To my thinking, all audio cables (except for umbilical from separate power supplies) carry alternating current. This is true whether you're talking about power cables, interconnects, or speaker cables.
    Just to satisfy my curiosity - I thought that interconnects/speaker cables which carry signals as opposed to power have a low enough voltage/current for the current to be direct, and that only direct current would work to drive, for example, speakers. Or am I wrong (quite likely ), hence this post.

    About the directionality issue - the point of ground hum would be obvious to the ears if the volume was low enough? But other than ground loop caused noise which would be of a gross kind, would there be any other change in sound quality caused by directionality? The brand name product literature seems to claim that to be the case if one sees the installation directions. Is that just clever marketing?

  6. #6
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    Default Cable directionality ...

    I think all the talk about directionality is bull. . . IMHO just my 2 cents.

    Bought a Supra directional cable and the yellow Van Den Hull cable and found no difference in terms of advantage. From my experience, once you reach a certain build level or material quality, the price-performance ratio quickly drops off. I use the yellow D-102 III Hybrid mainly because it's the cheapest high-quality cable I could find that sounds nice and actually looks quite good.
    There is an audible difference if you compare the D-102 to the el cheapo generic cables, but once you reach the level of the VDH, for me it's really a personal choice.

  7. #7
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    Default Directional cables for AC signals?

    Kumar "I thought that interconnects/speaker cables which carry signals as opposed to power have a low enough voltage/current for the current to be direct, and that only direct current would work to drive, for example, speakers. Or am I wrong (quite likely ), hence this post."

    Interconnects and speakers cables both carry an alternating current. It is this alternating waveform that represents the music you hear through your Harbeths or any other loudspeaker. If you're not comfortable with this explanation or my qualifications in giving it, let me submit three indirect proofs: #1) watch your full range driver cone: it goes both IN and OUT does it not? #2) manufacturers often list spec.s for capacitance and inductance for their audio cables; DC is not effected by either of these electrical properties. #3) If your amplifier actually did output a substantial amount of DC, for any length of time, your speakers would be long gone! You'd be talking to the warranty department rather than the Forum.

    Again, the only cables in an audio system that do *not* carry AC are the umbilical cables that attach an outboard DC power supply to the component. (It is possible to have pulsing DC that constantly changes in amplitude, but never crosses the Zero Axis and never reverses direction.) An example of this would be "ripple" on a power supply; a decidedly bad thing for audio.

    Another thing that might confuse you is the fact that speaker binding posts are often marked (+) Positive and (-) Negative. Don't confuse this with a battery, these markings refer to the polarity of the alternating waveform produced by your amplifier. The designer has it figured out that a positive going pulse should produce a compression, rather than rarefaction, and cause the cone to push outwards. The speaker will still work with the leads reversed, but polarity will be inverted 180*. This is audible to some people. If you invert only one speaker, then it becomes very audible. To me it sounds like you're listening inside the tank of a milk truck.
    Now, with regard to your questions about directionality: I'm not sure if it was my response that you were seeking, perhaps not. In my first post to this thread I identified two different aspects of cable directionality. The first refers to the practice of bonding of the shield to the signal common in an RCA interconnect. The idea, here, is to prevent ground loops or an alternate path for current to flow to ground. Generally, you would connect the plug with the shield / common connection to the *source end*. This would channel any noise picked up by the shield away from the signal's destination. This is the same in shielded power cables (bonded on the line side). This is more of a termination strategy; quite different from the claims of actual conductor directionality made by some manufacturers. What they are saying is that; a "directionality" (or favored direction for current to flow) is imposed on the individual strands of copper as they are drawn out of the casting machine.

    I believe that this is specific to OCC, Ohno Continuous Cast, or "single crystal" copper. If you go to the PS Audio website, they state that directionality is easily established by listening tests, and that they listen to a sample of every spool that arrives at their warehouse. PS Audio is far from the only manufacturer to make such a claim. Personally, I am sceptical of this, as stated earlier. If a wire conducts current better in one direction than the other, it is acting as a diode. Since all audio cables carry alternating current, this would not be a good attribute for a conductor to display. In all fairness, I would like to point out that this type of directionality is specific to OCC copper. I don't claim to have any knowledge of what is happening on the atomic level.

  8. #8
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    Default The danger of DC to the speakers

    Quote Originally Posted by Diminish View Post
    let me submit three indirect proofs: #1) watch your full range driver cone: it goes both IN and OUT does it not? #2) manufacturers often list spec.s for capacitance and inductance for their audio cables; DC is not effected by either of these electrical properties. #3) If your amplifier actually did output a substantial amount of DC, for any length of time, your speakers would be long gone! You'd be talking to the warranty department rather than the Forum.
    This is digressing from the subject of this thread, but I am no engineer and electricity is an even bigger mystery to me than mechanical things that tend to be visible, just curious and with enough knowledge to be dangerous - another way of saying little :-))

    Would not the speaker moves be triggered by changes in the level of even DC current passing through the voice coil, thereby varying the levels of electro magnetism which is what moves the speaker cones?

    {Moderator's comment: god forbid that there is any DC current passing through the speaker. DC at the speaker's input would move the coil/cone away from the natural rest position to another *fixed* position either offset inwards or offset outwards from rest depending upon how much current. Music superimposed on that non-central offset point would then be asymmetrically reproduced i.e clipped when loud because the cone would be able to travel further in either the ingoing or outgoing direction following the music. DC current and loudspeakers are a disastrous combination. A DC signal will heat-up the voice coil and if sufficient, fry it.}

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