Electrical shocks from the strings

Discussion in 'The Squawk Box' started by RayTorvalds, Aug 29, 2017.

  1. RayTorvalds

    RayTorvalds Senior Member

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    Hiya everyone,

    Not sure if this is in the right sub forum, but..
    I plugged in my guitar today and no sound was coming out of it. And I actually got some small electrical shocks from the strings. How on earth is that possible (earth/ground.. no pun) ?!
    It's working again, but I don't get how I would get shocks from my strings. They weren't powerful enough to hurt, but you could definitely describe it as uncomfortable.

    Is my amp breaking on me ? (currently playing on a Peavey Studio Pro 112 (solid state)). It is the only reason I can think of that would cause enough current to flow along my strings.
    I never had this before.

    Thank you in advance for any tips/explanations. :thumb:
     
  2. BluesRock

    BluesRock Senior Member

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    Sounds like a faulty ground on the amp.
    Do be careful. While it may only be a tingle when just touching the strings, if you touch a some well grounded metal while touching the strings the shock could be much more substantial (ask me how I know).
    Are you plugged into the wall using 3 prongs or 2?
     
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  3. RayTorvalds

    RayTorvalds Senior Member

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    I will surely be careful, thank you. The amp is plugged into a 2 prong socket, so no ground at all. (I'm in Europe by the way, so 220 VAC)
    It has never done that up till now.
    Regardless of it never having done it before. I should really make a 3 prong wall socket with a good ground ?
     
  4. DarrellV

    DarrellV Almost 1 Year old this month! Premium Member

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    Do you have an A/C Voltmeter, Ray?
    You could scare yourself really good touching one lead to a known good ground (like a radiator or sink drain) and the other lead to the strings.

    Remember even 90 volts can kill you, so you should get this checked.

    If this is the guitar you just re-wired, I would check to make sure your hot (signal) and ground (sleeve) aren't reversed on the guitar jack.

    Your wall jack could be wired reverse polarity. Your appliances won't notice, but you might. Like now.
     
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  5. DarrellV

    DarrellV Almost 1 Year old this month! Premium Member

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    Abso posi-lutly! Especially with guitars and mics!
    You have that ground wire running right to the strings inside that guitar.

    So if your amp is floating above earth potential at all, so are your strings!
     
  6. RayTorvalds

    RayTorvalds Senior Member

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    Yes I do have a multimeter. And yes, I do know 90 volts can kill you if the current (amperage) is high enough.
    It is indeed the guitar I just rewired. I will double check the jack connection (and the rest of the wiring again) tomorrow after work. But if those were reversed, wouldn't it do that every single time ? I played it plenty of times after rewiring it, but this is the first time it happened. Weird stuff.
    I will definitely make a 3 prong wall socket with a good ground.
    Thanks for the help Darrell and Bluesrocks:cheers2:
     
  7. DarrellV

    DarrellV Almost 1 Year old this month! Premium Member

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    That right there.:thumb:

    You may have done nothing different. It could be a differential in the mains voltage coming into your house, not caused by you directly.

    It could also be something has changed on your house grounding.
    This happened to a friend of mine a while back.
    His panel box ground wire for the entire house was installed wrong and his whole house ended up with a floating ground.

    Again, no one knew about it, but a couple people noticed things like dead frogs and a snake on the metal threshold of the outside door.

    One day his father in law stepped outside in bare feet and got a nasty shock.

    It was confirmed and an electrician brought in. He found the threshold plate and the whole house actually to be better than 90 to 100 volts above ground!

    Be careful!
     
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  8. RayTorvalds

    RayTorvalds Senior Member

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    Thanks brother, don't worry. I will be careful. A power company did indeed do some work on the power distribution box for our street.
    I will make a good ground as soon as I can. I will probably have to change some wiring as I'm pretty sure they are 2-conductor wires.
    I did just measure my output jack and everything is where it should be (ground and hot lead).
     
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  9. RayTorvalds

    RayTorvalds Senior Member

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    Actually, you got me curious now. How do you know ? What was the experience ?
     
  10. DarrellV

    DarrellV Almost 1 Year old this month! Premium Member

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    If that is the case you may want to notify them of what you found to be sure they haven't created a problem for you and others that they may not know about. 220 is no joke and very unforgiving.
    They should not charge you to check for problems especially in light of them possibly causing it.
     
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  11. RayTorvalds

    RayTorvalds Senior Member

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    Good call ! Especially for the "others". 220V is no joke indeed, and it hurts when you get to a "real" ground (instead of the guitar strings). I know that from experience.
    I tried to make a prank and scare my employer one day. When he was away from the company, I put this air-horn in a place where I'd think he wouldn't see it with a door bell switch to activate it.
    When he got back he noticed it instantly and made one of the wires (we have AC) ever so slightly sticking out so you would touch it when pressing the switch (I didn't notice it.. it was just like this really small hair of wire).
    Needless to say, I did feel it when pressing the switch trying to scare him. The joke was on me LOL... f*cker.. good one. We still laugh about that one every now and then.
     
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  12. DarrellV

    DarrellV Almost 1 Year old this month! Premium Member

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    LOL! That IS a good turn-about.
    My experience to remember was installing an industrial metal chop saw years ago that ran on 220 3 phase.

    The plastic cover was broke on the wall outlet and it was up about chest height on the wall.

    It must have been a hundred degrees (F) in there that day and I was drenched in sweat, including my arms.

    Well in the midst of tightening things down I somehow slid my wet forearm over the metal table of the saw and put my elbow right against the exposed contacts in the wall plug.

    Yeah, I saw lightning that day and my arm was numb and fuzzy for hours. Twitched for several days. Actually made my bones ache! Never felt that before!
     
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  13. BluesRock

    BluesRock Senior Member

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    I bought an old 1950 Fender Deluxe last year. I knew it needed some work but wanted to play it a bit in its "natural" state before I started replacing parts and wiring a 3 prong chord to it. I started to notice that I was getting a small tingle from the strings like you mentioned. After a few minutes I felt that it was time to turn the amp off, but before I did that, I decided to flip on my Mesa, which as it turns out has a well grounded metal power switch. I got a nasty shock that made my whole arm numb and tingly for several minutes and my finger that flipped the switch stung for a while longer. I was definitely lucky.
     
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  14. DarrellV

    DarrellV Almost 1 Year old this month! Premium Member

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    Nice! My favorite way by far has to be touching the mic while singing and playing and having the lightning shoot through my face and light up the backs of my eyeballs!
    In the old days I have been known to throw things after that!
    Worse than a slap in the face! At least you can see that coming!
     
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  15. RayTorvalds

    RayTorvalds Senior Member

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    Oh man, yeah I know what you mean by that. When I was starting as a car mechanic I once got a shock from one of those really high voltage transistor ignitions one time. My elbow joint hurt for 2 days. Mine was less worse than yours though. Glad you're still with us ! :thumb: 3 phase 220 (which is basically split up 380, if you use the 0 with every phase of the 380 separately, right ?) with a high enough amperage fuse can certainly kill you ! I once got a shock from a defect light bulb socket at 220vac, that kind of hurt too.. but not as much by far.
    Ouch !!

    -> Edit. Oh, and yeah ! That was certainly a good turn around. Well done by my employer.
     
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  16. RayTorvalds

    RayTorvalds Senior Member

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    Wow damn Bluesrock. Yeah especially with a tube amp ! Glad to still have you with us :thumb:
     
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  17. judson

    judson Senior Member

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    you guys are gonna make me switch to playing acoustics only.......

    can i be sure that 9 out of 10 times it will be the amp that is at fault? i do rewire things on my guitars and figured worse case i would not hear anything if i screwed something up there...

    i am not messing with anything inside my amps
     
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  18. DarrellV

    DarrellV Almost 1 Year old this month! Premium Member

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    Not completely true...... That's the darndest part about wiring electric guitars.

    You can wire the jack backward and you will still get sound. Its AC current anyway from the pickups so it doesn't care.

    But the only ground and safety you have is provided by the amp through the shield wire in the guitar cable.

    Reverse wire the guitar jack and your grounding apparatus in the guitar (including the strings) gets lifted to the signal side of the amp, and the ground gets fed into the pickups and pots.

    Oh yeah, you will likely get a nasty hum too, as the strings and other parts act as antennas to pick up and amplify the noise.
     
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  19. RayTorvalds

    RayTorvalds Senior Member

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    Yeah what Darell said and don't worry. Just don't ground yourself to a solid ground if you feel your pinky tinkeling when you touch your high E string :laugh2:
    From what I've learned so far and this thread is that it's either the amp or the socket it's connected to having ground issues (or no ground at all, like my socket).

    And yeah, if you are not 100% sure what you're doing. Stay away from the inside of amps for sure. Especially tube amps !
     
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  20. RayTorvalds

    RayTorvalds Senior Member

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    Oh and yes, tinkeling is a word.. It just became one :naughty:
     
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