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So I've been trying to setup a studio in my new two story house. My upstairs is a large one room, loft like area that I want to use as my control room. There is a small door upstairs that leads to a uninsulated attic like storage space. In that space I drilled a doorknob sized hole in the floor. Directly below that hole is a closet to a bedroom downstairs. That bedroom is the room I want to use as my recording room. I ran my 8 channel snake and a 1/4 inch extension cord (from my interface) through the hole in the floor to the bedroom downstairs. But whenever I try to plugin anything downstairs (headphones, microphone) I just get electrocuted by anything metal (microphone, metal end of headphones). Any idea why this is happening? Is there a solution?


OBrien Tue, 10/20/2015 - 20:36

Pretty convoluted you get what you play for.

It's like you have a puzzle you present that has nothing to do with the saying "I have a piece of string in my long is it?"

Recreate the issue. If it is happening in one place it will continue to happen until you narrow it down. If it is happening everywhere then you need local help not mine.

Btw...any McKnuckleHead that would use an upstairs uninsulated room in the onset of winter to house sensitive equipment is asking for trouble to begin with. Think of the heat exchange and the potential condensation coupled with the heat of the day.

Chris Perra Tue, 10/20/2015 - 22:55

It's some kind of grounding issue. I'd call an electrician.

Check to see if you're ok in one room everything plugged into the same breaker/outlet. Then check the other if they are both ok by themselves but don't play nice together. The you know it's a difference of the 2 of them. If you have shocks everywhere it has something to do with your gear or both rooms have a grounding problem.

Unless it's a piece of gear that you can troubleshoot call an electrician.

paulears Wed, 10/21/2015 - 00:35

For goodness sake. There are two main types of electric shock. Static shock where charge builds up, often through leaky capacitors and insulated metalwork on case etc, where when you are grounded, the charge leaks away through you. Usually very low current so it hurts but isn't dangerous. It can wreck sensitive equipment. The other type is much more dangerous and occurs when one of your items or a chain of them is carrying your full mains input voltage, 110 or 220v. If the path between this and ground is through you, then you can die. Incidentally you are dead if you have been electrocuted. If you are alive, you got a shock! Do not use your hand or body to test the problem, use a meter. Current through your heart will kill you. Using the back of your hand just means the thinner skin is a more sensitive to low current, high voltage surfaces, and if the current is high it will burn there rather than conduct through your body. If you suspect your equipment and are unskilled, do NOT touch it, get somebody in who knows! If you are competent, then stick a meter on it and measure.

As I understand it in America it is common for homes to have electricity supply from multiple phases to give 220v on certain outlets. If you have fed your kit from 110v on one floor, and other kit is supplied from somewhere else, then you have double the voltage available, and faults can be much more serious.

Ground loops, often spoken about are quite different. Very small voltage differences in the ground potential inducing hums. If something gives you a shock, then that is more serious. The safety ground may have been lost somewhere, and a different fault condition has occurred, that the lack of grounding is not able to protect you from. If you can't identify it yourself, then you MUST get somebody in. This is not something to fiddle with or get advice on a forum.

It could be a stray wire in one bit of kit, connecting live to ground, and a failed ground not tripping a breaker. It could be a safer problem. Tube equipment in fault conditions often put half the supply voltage on the chassis when things go wrong, centre tapped transformers sometimes being the culprit. So many causes, we can't guess at a distance.

The only advice is consult an expert.

If you know what you are doing, you could disconnect everything, spend a small amount on a meter and add kit, bit by bit checking the cases for voltage, one by one as you connect them. That, however, is stupid unless you can do it safely.

pcrecord Wed, 10/21/2015 - 02:54

Brien Holcombe, post: 433211, member: 48996 wrote: Polarity doesn't matter with AC goes in and it comes out.

Maybe polarity is not the right word.. remember I'm a french guy ;)
If I put the live wire to the outlet's ground pin and the ground wire to the positive or negative pin of the outlet. I think it mathers because you are sending live current to everything that is grounded..
Anyway, that's the idea why I suggested the tester. But even if that's not the problem, the tester cost is lower than 10$, everyone should have one ! If you get faulty results, you have an idea someone made a mistake in the wires and then you have something to say to the electrician... If every outlets of your home are OK.. I doubt an electician can help but hey... like other say, no chances to take !

paulears Wed, 10/21/2015 - 04:29

In AC circuits it is Live and neutral - the neutral nowadays is often exactly the same potential as ground where the cable comes into the building. You just can't say polarity, because it changes every 50/60th of a second.

Sticking a meter between say, the case of a microphone, and something grounded - like a water pipe (on the AC range) should give you zero volts. If you get a couple of volts, this can be quite normal, but be the reason you might get the odd hum. Anything over half mains voltage is worrying. In most cases of this, there is very little current - but still makes your lip or cheek tingle if your guitar is properly grounded and the recording equipment or mixer isn't! In the event of a proper fault, where the casing is connected direct to the mains live feed somewhere, then instead of a tingle, you will at best be on the floor, and worst - electrocuted and very dead.

A meter takes a short time to master, and at the very least, will warn you something is wrong. It won't help you fix it - but a reading of 110, or worse, 220 is enough to make sure you really do find somebody who can sort it for you. With the US mains voltage less than ours, the old electricians trick of a fleeting wipe of a suspicious wire is not quite so bad, and a few old timers here still do the same thing - but it's wrong and is a stupid risk to take. If you get a shock, touching it again is plain daft.

DonnyThompson Wed, 10/21/2015 - 07:19

Well, there's one thing for sure... getting shocked is not a "normal" occurrence, it points to a definite problem, and it's not something anyone should have to just "deal" with.

On top of the very real potential dangers of actual physical harm, you don't want really any of your gear seeing any voltage that it's not supposed to, either.

I'm not sure why the OP decided to post here - because there's no real way any of us can accurately diagnose the cause without actually being there ... and even then - personally speaking - my first contact would have been to a certified electrician...
And by "certified", I'm not referring to a neighbor, or a cousin, friend, or uncle who just so happens to own a voltmeter, or who has successfully managed to wire a light fixture in the past without burning their house down.

There are times when a "DIY" approach can work, but there are those occasions when you should just bite the bullet and call in an expert.
IMO, these "call an expert" occasions would include things like laying the foundation of a house, asbestos removal, messing around with gas or electricity...

It's not something I'd ever want to "guess" at... or in any way screw around with.
I'm not ready to die yet, so I have no desire to experiment with being a human grounding rod, and, I have way too much money invested in my gear to take a stab at solving a serious electrical issue on my own.
And I'd put "getting shocked" into the "serious" category.

But, that's just me. ;)

Bonemeister Fri, 01/27/2017 - 08:48

Electric Shocks in studio, practice room or live venue

If you are encountering a shock in your studio, practice room or at a live venue, the likely problem is that the electrical connection at the AC outlet has not been properly wired. What happens is that when you touch your guitar (connected to your amp) and a microphone (connected to your mixer or preamp) - you are in fact becoming a conduit for electrical current. If the polarity is reversed in one of the AC outlets, and the U ground connecting your guitar amp to the AC has been either removed or your amp is a vintage one without a 3rd prong, you become a short circuit and experience a shock.

The electrical system used in homes and offices in North American employs AC a series of 110V (15 amp) outlets that are distributed around the home and office. [In Europe - 220v or 240V outlets are employed that typically feature a lover current (7 amp)]. Wiring from the main electric panel comes into the house at 220V and then is split with 110v on each side of the panel. There are 3 wires connecting from the panel to each outlet. Black is power, white is the return path and copper is the safety ground. Today, the AC outlet itself is color coded with gold for power, silver for return and green for ground. Think of black-gold (oil) as a simple reminder. If - when the house was wired, the black wire and the white wire were mistakenly reversed, the AC outlet will still work. This is the nature of AC as it is bi-directional. However, when two electrical outlets are combined via secondary connection (ie audio) this is where you get into trouble.

The easiest solution is to buy a simple AC tester from your local hardware store. This is typically equipped with a series of LEDs to tell you if the outlet is properly wired. If it is not, you can easily fix the problem by turning off the breaker (test with a light) and then rewiring to follow code. If you are not technically comfortable or competent, simply have an electrician do the fix for you.

One other point: if your electrical system is wired properly and you are experiencing noise (hum and buzz) when connecting two audio devices together such as two guitar amps, never - and I mean never - remove the U ground by cutting it off or using a cheater to lift the ground. This is sometimes done to reverse the amps polarity and eliminate noise. This can kill you for the reasons mentioned above and if a fire breaks out, can void your fire insurance as it is illegal. A better solution is to connect both devices to a power bar that shares the same electrical outlet. Another solution is to insert an isolation transformer into the audio path. Radial makes these for both balanced and unbalanced systems.

Peter Janis - Radial Engineering

paulears Fri, 01/27/2017 - 12:36

The advice to get in somebody to check is a really sensible solid one if you don't have the knowledge. As in the UK we have a much higher mains voltage (240V again, once we do the Brexit thing) and the standard UK outlet can supply up to 13A - this means that here tangling with electricity is pretty dangerous. The US system of having 2 separate mains delivery phases to give users a choice of 110 or 220 doesn't happen in the UK in most homes. Just one single phase - but, for the sake of the record, our delivery system has the capability for 3 phases, and in some homes where there is extra need (like me where I work from home in an extension to the property, I have two phases of the three that pass by in the street. The voltage between phases is (or soon will be) 415V - serious amounts of electricity. We have a saying here - the Volts jolts, but mils kills. It's fairly common, despite all the modern concern with safety, to find grounds that are either not very good, or unconnected. On top of this, lots of equipment that has tubes inside, especially older guitar amps seem to leak current to ground, and when the ground is divorced from the 'real' ground then guitar strings and microphones can have voltage on them. The amor design means that this is usually half the mains voltage - so 60V in the US, but 120V here! Playing your grounded guitar and then touching your lips to the mic hurts like hell. However, there is hardly any current, so thankfully rarely terminal. It does of course mean that the system is prone to fatal results if the amp or other device removes the current limiting, or has maybe been repaired poorly. The back of the hand is also very sensitive, and I too tend to use this part of my body to check things. You could of course connect a good ground to the bad ground and that low current source would be dumped to ground. If there is a real fault, doing this puts the maximum current through cables not meant for it - those cheap short guitar pedal links are often made with very thin screening, and they can actually go bang, acting like a fuse!

One thing is for certain - any piece of equipment that produces a tingle, or a painful jolt should not be used. Worse still, the item that gave the shock, may not be the culprit - it could be elsewhere. Another good reason to get the kit checked.