Hi guys,

I have written about this on this forum before. My wife sometimes interrupts my guitar practice by tapping my arm. She swears she can feel an electric 'pulsing' through my skin. I thought she was exaggerating or something. However, last night she touched the guitar strings and I touched her face. I could definitely feel a pulsing through her skin, like something trying to get out. It was not subtle or gentle it was unmissable and stopped as soon as she let go of the strings. My guitar was plugged in to my amp but the amp was switched OFF.

I unplugged my Strat and plugged in my Jazz bass and we repeated the experiments. The amp was still off. The pulsing was there on both of us.

As I said the amp was OFF but it was plugged in to the mains. I unplugged the amp from the mains and we repeated the experiment. This time there was no pulsing.

In the past in talking to Ryan on this forum (a fellow expat in Korea) we have found that it is likely that my apartment electricity supply has no earth. My guitar and amp are very noisy with in my room. This does not happen elsewhere. However in this case the amp was connected to the mains but it was not turned on. I wonder if these are connected..

Any ideas? Am I in danger?

Cheers,

Tony

Quote BigElectricCat:

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Any ideas? Am I in danger?

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Hi Tony,

As you say, we've had quite a few discussions with yourself and Ryan about your local power in Korea. And while there are some very knowledgeable and qualified electricians here who are very helpful, trying to solve mains power supply issues remotely by forum Q&A's is far from ideal.

And in safety terms I would suggest that trying to resolve these problems on a web forum, even one as good as this, is inherently dangerous. Why? Because all it does is delay what you should be doing, which is finding a local, reputable, qualified electrician who can check the house wiring for safety and explain to your satisfaction what is causing this issue. It may be nothing of any consequence, but it could be the only warning you get that you are unprotected if something else goes wrong with the domestic power supply.

Andy

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When the going gets weird, the Weird turn Pro.

Yes, you could well be.

Keep well away from earthed metal objects when playing guitar!

You really need to get a good electrician in there.

Dave.

Quote ef37a:

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Yes, you could well be.

Keep well away from earthed metal objects when playing guitar!

You really need to get a good electrician in there.

Dave.

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Thanks for your replies guys.

I fully intend to get a local electrician to come and check out my electricity supply in the near future. However, I am confused as to what is or could be happening.

I am no electrician. What could explain these effects? Especially considering the amplifier (which was serviced last summer)was switched off.

My rudimentary understanding of the physics of an electric guitar is that the metal string vibrates in front of a magnet creating a tiny electrical current. Is this correct?

The amplifier shouldn't be passing any current to the guitar, right? The pickups and the strings are not 'live' and since two separate guitars exhibit the same problem faulty wiring in the instrument seems unlikely although not impossible.

I'm really curious to know what could be causing these effects? I'd especially like to have some ideas before I'm in the situation where I am dealing with a Korean electrician.

Cheers,

Tony.

Quote BigElectricCat:

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I fully intend to get a local electrician to come and check out my electricity supply in the near future.

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No. Do it today. Good intentions aren't much good if you or a loved one get electrocuted!

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However, I am confused as to what is or could be happening.

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Without being there and able to test the system it's difficult to give a precise answer, but as Andy and Dave have suggested, it has all the hallmarks of either having a mains system in the building in which the safety earth terminal is not being earthed properly, or the supply has been miswired in the wall outlets and the live terminal is wired to the ground outlet etc.

However, from your description I would hazard a guess that the safety earth connection in the wall socket is missing. If that is the case, then all manner of equipment plugged into the supply in your house and possibly your neighbours too -- and including your own amp -- is likely to have mains inlet filters that will cause the safety earth (and thus the earthed parts of your amp and the guitars you plug in to it) to rise up to around half-mains supply voltage.

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Especially considering the amplifier (which was serviced last summer)was switched off.

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If the building's mains supply earth is not bonded properly it won't matter whether the amp is switched on or not. The guitar strings are connected to the amp ground, and if the amp ground is connected to a supply in which the ground is floating around at a high voltage, or if the supply has been miswired to the wall sockets, you'll feel that pulsing throb because your feet will be more or less grounded to true earth potential.

THIS IS A VERY DANGEROUS SITUATION

Something is very seriously amiss here. It sounds very much like your mains supply wiring is defective and is undoubtedly potentially lethal. GET IT FIXED TODAY.

Hugh

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Technical Editor, Sound On Sound

Quote Hugh Robjohns:

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Quote BigElectricCat:

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I fully intend to get a local electrician to come and check out my electricity supply in the near future.

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No. Do it today. Good intentions aren't much good if you or a loved one get electrocuted!

Quote:

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However, I am confused as to what is or could be happening.

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Without being there and able to test the system it's difficult to give a precise answer, but as Andy and Dave have suggested, it has all the hallmarks of either having a mains system in the building in which the safety earth terminal is not being earthed properly, or the supply has been miswired in the wall outlets and the live terminal is wired to the ground outlet etc.

However, from your description I would hazard a guess that the safety earth connection in the wall socket is missing. If that is the case, then all manner of equipment plugged into the supply in your house and possibly your neighbours too -- and including your own amp -- is likely to have mains inlet filters that will cause the safety earth (and thus the earthed parts of your amp and the guitars you plug in to it) to rise up to around half-mains supply voltage.

Quote:

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Especially considering the amplifier (which was serviced last summer)was switched off.

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If the building's mains supply earth is not bonded properly it won't matter whether the amp is switched on or not. The guitar strings are connected to the amp ground, and if the amp ground is connected to a supply in which the ground is floating around at a high voltage, or if the supply has been miswired to the wall sockets, you'll feel that pulsing throb because your feet will be more or less grounded to true earth potential.

THIS IS A VERY DANGEROUS SITUATION

Something is very seriously amiss here. It sounds very much like your mains supply wiring is defective and is undoubtedly potentially lethal. GET IT FIXED TODAY.

Hugh

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Thanks Hugh, I appreciate your answer.