Shocking Review

admin · Post by **admin** » Mon Nov 14, 2005 3:17 am

In my music room I have run into a situation in which, all of a sudden, I get my lips electrified should I touch them to the microphone inadvertently. Something has obviously changed but I cannot think of what that might be.

All of my AC receptacles are grounded and I have three prong plugs on my amplifiers. I have several effects pedals that I use as well. Further, the ground switches on the back of the amplifiers have all been tried in all positions and this shocking experience continues.

I am aware that microphone shocks may be caused by a faulty guitar amplifier that is leaking AC current onto its chassis. But why would this shocking situation suddenly happen over the course of perhaps a few days when it was not a problem before. So what is the likely culprit?

leftyguitars · Post by **leftyguitars** » Mon Nov 14, 2005 6:38 am

Is the shock a quick "zap" and then OK or is it a continuous shock? If it is the second one, does the shock throw you away from the mic. or hold you to it?

admin · Post by **admin** » Mon Nov 14, 2005 6:55 am

Peter it is a continuous shock. As to your second question, it seems to put you in quickly at the beginning but then the feeling is one of being thrown away.

ken_j · Post by **ken_j** » Mon Nov 14, 2005 9:31 am

I would check all outlets and equipment for an open ground or white wire. This could cause a back feed.
Also: Just call me anal, but I don't like different pieces of gear plugged into outlets that are wired to opposite legs in the circuit panel giving a 220V potential.

soundmasterg · Post by **soundmasterg** » Mon Nov 14, 2005 2:43 pm

I'm shocked that this is happening to you Peter!

Ken's got it right here. Something has changed in the last couple days and something has a faulty ground connection I would guess. Either one of the amps or the mic itself. Do you have any other mics or mic cables to try?

admin · Post by **admin** » Mon Nov 14, 2005 3:10 pm

Thanks for the current information guys. I thought for a moment it may have been a phase I was going through.

But the problem is more global as it is reproducible with different amplifiers and two different AC receptacles and several microphones. By the way, it is quite a zap.

I volt for an open ground problem but I cannot explain why that has happened over such a very short period. I'll try to stay neutral about it until I get a chance to explore it further.

winston · Post by **winston** » Mon Nov 14, 2005 3:17 pm

I guess you were kind of "shocked" to find out that you have a "ground" problem.

admin · Post by **admin** » Mon Nov 14, 2005 3:34 pm

Right your are Brian, I am afraid that I have been asleep at the switch. Watts up with that?

ozover50 · Post by **ozover50** » Mon Nov 14, 2005 4:53 pm

You weren't doing AC/DC's 'High Voltage' at the time, were you, Peter?

admin · Post by **admin** » Mon Nov 14, 2005 4:57 pm

No Howard but I did break into, "I'm a lineman for the county..."

ozover50 · Post by **ozover50** » Mon Nov 14, 2005 6:18 pm

Followed by Hall and Oates' "Your Sizzle's On My Lips"??

alanz · Post by **alanz** » Mon Nov 14, 2005 7:44 pm

Situations like this get me amped up, too.

leftyguitars · Post by **leftyguitars** » Tue Nov 15, 2005 12:34 pm

Peter, I'm not 100% sure of the wiring regulations in the USA but if it is anything like here in the UK you really need to test the house electrics first with a high voltage tester (a megga or similar which whacks 500 - 1000 volts through the relevant circuit and measures for leakage, shorts, open circuits or other problems). Do you have a "proper" earth (ground) in the house supplied by the incoming cable or do you have an earth rod hammered into the ground with an earth wire connected to it? If it is the second, check that it has a good connection.
Secondly you really need your equipment testing with a "portable appliance tester" (which checks earth leakage, insulation breakdown, etc). Needless to say, you need a suitably qualified person to do all this. I would offer my services but I'm a bit too far away!
Lastly, a common problem (but I think not yours) is static, common causes of this are man made materials in carpets, trainers, etc. but this would generally be a harmless (but painful) short whack at the contact area often with a good healthy spark.

admin · Post by **admin** » Tue Nov 15, 2005 2:00 pm

Thanks Peter. I appreciate your sound advice. This is serious current from my perspective. I suspect an open ground but I'll see what can be unearthed tomorrow and report the findings.

brammy · Post by **brammy** » Tue Nov 15, 2005 8:15 pm

hmmmm.... I'm all ears on this one. I guess this was one of the reasons they made those foam wind screens. I've always suspected they had at least as much to do with lip-zaps than with wind.

My only 2-cents is that I've occasionally encountered this when playing in new places and then it went away upon returning to the secret band batcave..... meaning that the fault was with the venue wiring, not my amp/guitar/mixer. Other than that, like Sgt Schultz, I know nuuuuthing.