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This Little Amp Is Trying to Kill Me and My Girlfriend

Discussion in 'Shock Brother's DIY Amps' started by ArcticWhite, May 22, 2020.

  1. Jay Jernigan

    Jay Jernigan Tele-Afflicted

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    I read every post on every page, looked at every picture, digested the information, posted what I considered a thoughtful and non inflammatory reply to what has become a flaming shoot-out over nothing.
    You plugged your little semi-homemade seven watt amp into an improperly grounded socket in your garage and got bit.
    Get over yourself.

    (Would someone please close this thread?)
     
  2. bloomz

    bloomz Tele-Holic

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    I remember well in my 60's band being shocked many times by lips touching a mike. IIRC we would flip the power plug upside down to fix it? I don't believe power plugs had one big side like they do now.

    And, wasn't it the Silvertone (my first2 amps, the guitar case one and a 1484) that was/is famous for the death cap?

    Guess we're lucky to be alive.

    Come to think of it - I *think* that Silvertone 1484 is still in my attic. Eek!
     
    Last edited: Jun 3, 2020
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  3. awasson

    awasson Poster Extraordinaire Silver Supporter

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    Good idea. I think most of us who have played guitar and had junk store amplifiers have had some experience with this. I keep one of those circuit testers in my gig bag now too (not that I've been out playing for a few years but just in case).

    Yep, This guy gets it.

    There was nothing quite like being plugged in, hand over your strings to dampen the guitar and grabbing the mic stand or grabbing your buddies guitar to pass it to him. Zaaaapppp! :confused:
     
    Last edited: Jun 3, 2020
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  4. koolaide

    koolaide Tele-Afflicted

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    I could be wrong, but I think the OP gets the how, but not the why. I can relate to that. I am not an EE, I am a self taught well read/studied hack. If I am correct he wanted to understand why his point to point- moded amp shocked him and his GF, and when it was explained that it was the ungrounded receptacle, he got it. But then wanted more understanding in how in the land before grounded receptacles the two prong receptacle worked.

    I believe the answer he was/is looking for is polarity. Essentially of the two wires, one (white neutral) was/is the return- grounded conductor and one(black hot) the ungrounded-line conductor (120-VOLTS in US). the prongs were the same size and one could and did put the wrong prong in the wrong hole. If this occurred the plugged in device works, but parts of the device that were not meant to, could become hot for various reasons- poor design, failed(leaking capacitors) components..... the list goes on. As evidenced by the numerous replies it was common knowledge at the time. Not so much now. Still there were many people killed before(and after) 3 prong (grounded), polarized (differing size prongs for neutral and hot) plugs/recepticals.

    The above is my 3rd grade graduate understanding. I am aware the subject is much deeper, and I acknowledge that I lack a complete understanding of electricity and the physics behind it. Accept this information at your on risk. This is simply my understanding. YMMV
     
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  5. Asmith

    Asmith Friend of Leo's

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    I think you're right about the OP wanting to know why but your explanation isn't quite right.

    I'd assume the amp was built nearly from the ground up, modding a P2P amp without a layout guide would be a ridiculous task.

    This amp was never a widow maker it had/has a power transformer so the plug polarity was never an issue but the transformer was part of the issue.

    The transformer as well as stepping up/down voltage also removes it's DC voltage like a capacitor. An output transformer is almost always at 250 to 500VDC on the primary side in guitar amps but is at 0VDC on the secondary where the speaker is.

    Since his ground connection on the secondary side of the power transformer was disconnected it didn't have any VDC reference and we call that a floating ground. The floating ground can drift of by enough volts to give someone a shock. It won't be enough to do any harm providing the amp is healthy otherwise but in the event of a fault you could get zapped by deadly voltage with enough current to back it up.
     
  6. koolaide

    koolaide Tele-Afflicted

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    Missed it by... that much:D.
    Thanks for the education.
     
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  7. ArcticWhite

    ArcticWhite Tele-Afflicted

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    Thanks. This is it, exactly.
     
  8. SAguitar

    SAguitar Tele-Meister

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    My Guitar Wants To Kill Your Mama

     
  9. tele_savales

    tele_savales Tele-Holic Platinum Supporter

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    But we got electrocuted regularly.
     
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