SDA 2.3's Pin/Blade cable....revisited

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avguytx
avguytx Posts: 1,628
edited October 2007 in Vintage Speakers
I'm down to the final stages of the rebuild of these SDA 2.3's for my buddy's birthday next week and I have a question for the pros on the Pin/Blade IC. In the Compendium, it says that the Pin only carries a connection and the blade is there for "support". If so, I was just going to add a binding post to replace that connection for the single "Pin" connection. But, looking at the back of the terminal cup (see pic), you can see that the blue lead (Pin) goes to the molex plug which has it's location on the crossover board. Well, the white lead (Blade) is paralleled in on the bottom binding post, wires to the molex, and "appears" to be active (so to speak) on the crossover board.

So, long story short. Even though it doesn't look like it, is it only the Pin that carries a signal? I hate to put only one binding post on to find out that it needs both! These didn't come with the Pin/Blade cable....thus the need for making something.
Richard? Who's your favorite Little Rascal? Alfalfa? Or is it........................Spanky?.................................Sinner.
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  • Ricardo
    Ricardo Posts: 10,636
    edited October 2007
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    I think that the blade in the socket is connected to ground (negative post) just for the use of the A1 interconnect. If you don't plan to use one, then one binding post is enough. Many of us did it like this.
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  • george daniel
    george daniel Posts: 12,096
    edited October 2007
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    I replaced mine with a single binding post(in place of the pin)
    JC approves....he told me so. (F-1 nut)
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  • avguytx
    avguytx Posts: 1,628
    edited October 2007
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    That works for me. I just wanted to confirm with the pros and make sure it wasn't some in-between model of some sort! Thanks, guys...
    Richard? Who's your favorite Little Rascal? Alfalfa? Or is it........................Spanky?.................................Sinner.
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  • heiney9
    heiney9 Posts: 25,092
    edited October 2007
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    HTrookie wrote: »
    I think that the blade in the socket is connected to ground (negative post) just for the use of the A1 interconnect. If you don't plan to use one, then one binding post is enough. Many of us did it like this.

    I think that's correct.

    I would caution that perhaps leave the original pin/blade receptical in tact and put the modified socket above it. This way if someone in the future has a need for an AI-1 cable it can be used. My 1C's were modified with a female plug for a bananna connector and now I would like to use the AI-1 cable but can't unless I modify it back to the orignal pin/blade connector. I'm sure there is another work around but it seems to be a lot of trouble.

    Just my .02c

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
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  • Ricardo
    Ricardo Posts: 10,636
    edited October 2007
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    Yes, if you have the original AI-1 it can be a pain, but if you build one, like many do, you can just connect the "pin" wire to the corresponding binding post, and the "blade" wire to the lows negative post.
    _________________________________________________
    ***\\\\\........................... My Audio Journey ............................./////***

    2008 & 2010 Football Pool WINNER
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    Thank God for different opinions. Imagine the world if we all wanted the same woman
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  • heiney9
    heiney9 Posts: 25,092
    edited October 2007
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    HTrookie wrote: »
    Yes, if you have the original AI-1 it can be a pain, but if you build one, like many do, you can just connect the "pin" wire to the corresponding binding post, and the "blade" wire to the lows negative post.

    I see, so since my 1C's aren't bi-wireable I could still connect the corresponding "blade" wire to the negative speaker post.

    That helps a lot and I'm much more inclined to possibly build my own, then I can get what ever amps I want. Part of the frustration is trying to determine if a particular amp is or is not common ground and as I've found out "common ground" means differerent things to different people. I'd just like to fix the situation once and for all by making my own AI-1 cable.

    Thanks Ricardo :)

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
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  • DarqueKnight
    DarqueKnight Posts: 6,765
    edited October 2007
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    The blade socket of a pin/blade jack does not accept an audio signal since both wires of a pin/blade cable are attached to the pin.

    The blade socket has a wire attached to it because it is used for testing purposes and it is needed for the AI-1.

    I added a single binding post for the SDA cable on all my SDA's and left the stock jack intact.
    Proud and loyal citizen of the Digital Domain and Solid State Country!
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  • heiney9
    heiney9 Posts: 25,092
    edited October 2007
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    One related question can the AI-1 interphase be used with a common ground amp w/o issues. Issues such as damage or severe sound quality issues?

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
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  • DarqueKnight
    DarqueKnight Posts: 6,765
    edited October 2007
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    The AI-1 is only specified for use with non-common ground amps. Why would you want to use it with a common ground amp?

    I don't know of any issues with using the AI-1 with a common ground amp, but I do not have any personal experiece with the AI-1.
    Proud and loyal citizen of the Digital Domain and Solid State Country!
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  • heiney9
    heiney9 Posts: 25,092
    edited October 2007
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    DarqueKnight wrote: »
    The AI-1 is only specified for use with non-common ground amps. Why would you want to use it with a common ground amp?

    I don't know of any issues with using the AI-1 with a common ground amp, but I do not have any personal experiece with the AI-1.

    Just in case I end up using it with a common ground amp. Seriously, it's hard when you are trying to buy an amp to determine short of having the seller use VOM meter at the speaker terminals.

    My big question is if Monarchy SM70's when run in stereo are common ground. I know when run in single ended balanced mono they aren't. I posed the question of common ground to Nelson Pass and he gave me a cryptic answer. So in the event that I can't conclusively determine if an amp is common ground to be safe I would run it with the AI-1 cable.

    Sounds pretty lame

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
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  • DarqueKnight
    DarqueKnight Posts: 6,765
    edited October 2007
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    I would advise sending your question to Ken Swauger in Polk Customer Service and ask him to pass it to their engineering department.
    Proud and loyal citizen of the Digital Domain and Solid State Country!
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  • heiney9
    heiney9 Posts: 25,092
    edited October 2007
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    DarqueKnight wrote: »
    I would advise sending your question to Ken Swauger in Polk Customer Service and ask him to pass it to their engineering department.

    Thanks Raife, just doing some thinking outloud. :)
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
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  • avguytx
    avguytx Posts: 1,628
    edited October 2007
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    DarqueKnight wrote: »
    The blade socket of a pin/blade jack does not accept an audio signal since both wires of a pin/blade cable are attached to the pin.

    The blade socket has a wire attached to it because it is used for testing purposes and it is needed for the AI-1.

    I added a single binding post for the SDA cable on all my SDA's and left the stock jack intact.

    Interesting. I guess it confused me when I traced it back to the crossover board and it looked like it was in the signal path. If not, then I'll add a single binding post and be done. I know I won't have to worry about my buddy running various amps. Once he gets the amp on them, he'll pretty much be done. (or so I think) But at least if he does, I know he'll ask me first! :D
    Richard? Who's your favorite Little Rascal? Alfalfa? Or is it........................Spanky?.................................Sinner.
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