Conductivity calculation for Duelund Silver interconnect (vs DGA20GA)

Discussion in 'Audio Hardware' started by Kasper Bergholt, Aug 19, 2021.

  1. Kasper Bergholt

    Kasper Bergholt Active Member Thread Starter

    Hi all,

    I've used Duelund wires for speaker cables for years. A couple of months agso, I had a set of unshielded interconnects made.

    These are based on DCA20GA wire terminated with Switchcraft RCA plugs known from Jeff's Place & The Audio Beatnik (amongst others). I can see both speaker wires & interconnects are popular on this forum too.

    Next, I'd like to experiment with both a shielded version of the DCA20GA, perhaps with RCA connectors from Audio Note ord KLE Innovations - and a set of interconnects based on Duelund Silver wire.

    There are three different types: 1.0, 2.0 and 3.0. I'm trying to figure out what the three types of wire correspond to in the GA system (i.e. same conductivity & capacitance as the DCA20GA).

    The DCA20GA is 1.8mm with and internal diameter of 0.95mm - this wire is made from tinned copper.

    Data on the three types of silver wire:

    Silver 1.0
    Internal foils measures - 2.5mm width by 0.25mm height; External measurements - 3.9mm width by 2mm height

    Silver 2.0
    Internal foils measures - 4.5mm width by 0.25mm height; External measurements - 5.65mm width by 2mm height

    Silver 3.0
    Internal foils measures - 4.5mm width by 0.25mm height; External measurements - 5.65mm width by 2mm height

    So my question boil down to this: Which of the silver wires corresponds mostly closely to the DCA20GA.

    In addition, I'd be very happy for any feedback, experiences og tips.

    Thanks in advance,

    Ingenieur likes this.
  2. Kasper Bergholt

    Kasper Bergholt Active Member Thread Starter

    Ingenieur likes this.
  3. Davey

    Davey NP: Luke Howard ~ All of Us (2022)

    SF Bay Area, USA
    20ga copper has cross sectional area of 0.52mm squared, but diameter of 0.81mm, so sounds like yours is 19ga if diameter is 0.95mm, which has area of 0.65mm squared, and the silver 1 has area of 2.5 x 0.25 = 0.625mm squared, so similar in size. Hookup wire on its own doesn't have a capacitance unless it is paired with another wire. Both wires use cotton and oil for the insulation, so should have similar capacitance when paired with another wire spaced at an equal distance, but the actual capacitance value would depend on the spacing between the wires.

    Shielding introduces another variable, and another capacitance value.
    Last edited: Dec 5, 2021
    jonwoody and Ingenieur like this.
  4. Ingenieur

    Ingenieur Forum Resident

    The best way to determine this is to get a few feet of each and measure the parameters.

    here's a chart

  5. Kasper Bergholt

    Kasper Bergholt Active Member Thread Starter

    Thank you! :)
  6. Kasper Bergholt

    Kasper Bergholt Active Member Thread Starter

    Thank you - but this does not take the difference between tinned copper and pure silver into account?
  7. harby

    harby Forum Resident

    Portland, OR, USA
    The relation between gauge, diameter, and area is the same whether we are discussing silver, gold, staples, or chicken wire.

    The 0.625 cross-sectional area of 2.5mm x 0.25mm is 0.625, under 19ga. However, that dimension is specious in this wire, not describing the area of solid billet silver but of the dimensions the folded foil occupies.

    What doesn't change with metal is inductance (except to the degree that construction dimensions can be altered), being the amount of flux around a current or between two current-carrying conductors and in a dielectric material.

    What also doesn't change is capacitance, except on a very minute level, because that is the accumulation of charge and energy in an electric field and dielectric.

    Why on a miniscule level? Because at high frequencies (much higher than you'd be hearing), different conductors have a different skin-effect depth, with silver exhibiting more skin effect than copper, putting more charge at the surface.

    The only change is indeed conductivity/resistivity, silver being a better conductor by 5.7%. This degrades as the silver tarnishes (not oxidation, but sulfidation), the poor conduction observed by Faraday nearly 200 years ago, and denied by cable makers, especially those who maximize surface area.

    Conductivity benefit is usually more than negated by "audiophile" silver cables being made of tiny conductors to maximize profits off those who like precious metal bling, obfuscated by non-standard descriptions of the amount of material actually used (and letting dealers instead make the "18 gauge equivalent" Silver 1.0 claim just short of fraud). And poetic fiction: "this means the cable does not see any static charges, creating a completely undisturbed sonic image, completely devoid of plastic artifacts."

    There is no reason to make an intentionally unshielded wire for RCA, especially when driven by unmatched impedances and where the cabinets of equipment touching would provide a better path than the wire - unless you like the musicality of receiving radio transmissions in your gear.
  8. Kasper Bergholt

    Kasper Bergholt Active Member Thread Starter

    Those are _very_ good points! Thank you :)

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