A1 Isolation transformer for Polk Audio SDA 2B

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VSAT88
VSAT88 Posts: 1,379
in Vintage Speakers
I have the SDA 2B's that are blade blade therefore one active conductor in the interconnect. In order to use an A1 / Dreadnought style isolation transformer I need connect a wire from the negative terminal binding post to the unused blade on the back of the blade terminal. Is that correct ? That is what I recall anyhow.
Not gonna do anything till I know though...Thanks.
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  • pitdogg2
    pitdogg2 Posts: 27,775
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    That is how pin/blades are inside speaker.

    So yes if yours are not true B/b you can do that
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  • VSAT88
    VSAT88 Posts: 1,379
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    Then another question. Do I even need to send the speakers negative connection thru the transformer at all. I know that would connect or make common a wire between both speakers but is it necessary ?
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  • pitdogg2
    pitdogg2 Posts: 27,775
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    VSAT88 wrote: »
    Then another question. Do I even need to send the speakers negative connection thru the transformer at all. I know that would connect or make common a wire between both speakers but is it necessary ?

    Very necessary if you have non common ground or mono's. I would do it.

    How is it hooked up inside now?
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  • VSAT88
    VSAT88 Posts: 1,379
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    Right now everything is stock. I hope I am answering your question correctly. It is wired exactly like this. (Image by Gimpod)c7iin9e90dwd.jpg
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  • VSAT88
    VSAT88 Posts: 1,379
    edited July 2020
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    Well not that it matters but I am using speakON Cable Connectors - Neutrik.

    The amplifier is common ground. McCormack DNA 1.
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  • pitdogg2
    pitdogg2 Posts: 27,775
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    OK just checking

    If it was me I'd hook up the blade(speakon) to the negative if I was going to be in there and be done.

    ;)
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  • VSAT88
    VSAT88 Posts: 1,379
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    Perhaps that is what this means ?? I am going in to do it as I have more work in there. I am trying out some oil filled capacitors in the 20uF and 40uF positions for the midwoofers. Thank you @pitdogg2

    rznow5eckj7c.jpg

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  • F1nut
    F1nut Posts: 52,305
    edited July 2020
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    No, that's nothing to do with it. That is for the TL mod, which requires the small faston on the negative lead to the tweeter be changed to a large faston.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."

    President of Club Polk

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  • VSAT88
    VSAT88 Posts: 1,379
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    Check that. I read that before and didn't understand it. I naturally changed the faston. I understand it perfectly now. The "HF harness" is referring to the speaker wire between the crossover and the new tweeter.
    How about this for internal speaker wire ?
    https://www.madisoundspeakerstore.com/speaker-wire/supra-rondo-2x2.5mm-speaker-wire-per-foot-13-awg/
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