blubs

Hi All,

I need the bottomless pit of Scooby people knowledge here please!

Just started practising with a new band and I'm getting zapped through the mike when I touch it with my lips

We tried the process of elimination;
Different mike - zap!
Different mike lead - zap!
Change all leads on PA - zap.

It only happens to me, even if I use the guitarists mike. If the guitarist uses my mike he is ok. Then I thought could it be me through my amp via the guitar strings? Is this possible.

Anyway, if i touch the mike without playing i'm ok. If i start playing and singing then i get zapped - everytime. I changed the guitar leads to the amp, my amp power lead and even the mains power trip but its still happening.

Could it be an inherent fault in the amp or the guitar (which is brand new). Or is there some techy meter that could find the problem?

The amp is a Marshall VS220.
Guitar is Gibson SG standard.

Help!

Cheers

blubs

hedgehog

Is it a real zap or just static?

I assume that you feel it is a real zap carrying some current. If this is the case then you need to be really careful as, given the wrong circumstances it might be enough to kill you. With this in mind you really want to see where the problem lies.

Without being there and doing some testing it is impossible to be sure but it does sound like the earth in your amp might have mains on it. Have you lifted the earth on the plug of the amp to rid you of hum loops? If so get it back on asap before you kill yourself.

There are devices called PAT testers which can test gear for electrical safety and it might be that the company you work for may have one, worth asking the sparks if you employ any. Get someone who knows what they are doing to test your amp and see how it fares.

Not much info i know but it is hard to tell without getting hands on the gear. Whatever you do be very careful.

unclebuck

Lethal.. I saw someone almost die from exactly this. He fell and the live mike stand fell on top of him, electricuting him even more.

It was to do with dodgy earthing of the power generator they were using IIRC. Get a *proper* qualified electrician to sort it out.

ScoobyDoo555

yep - get a sparky to check it out. This type of thing can be a killer Not saying your situation is, but you don't want to tale the chance.

My guess is your amp or the PA - poor earthing ground somewhere.

Dan

Bubba po

As everyone else says, it's most likely an earth wire off somewhere. As the other guitarist isn't getting a belt when he touches both mike and guitar, It is unlikely to be an earth fault on the PA or of the practice venue. Musical gear is really prone to damage as leads are tripped over, plugs pulled in and out of sockets etc. It's also unlikely that you've got mains current coming through your earth connection, though not impossible. It's possible to get a fair shock off an earth circuit without it being mains-level current. Open your amp plug and check that all the wires are secure and that the cord grip is actually gripping the sheath. It's worth getting someone who really knows how to wire a plug properly to do it for you. Also do the same for every single extension lead that you use in your band set-up.

Then get yourself an RCD circuit breaker. Your life may depend on it if you play live regularly.

Chip Sengravy

Freak

Someone has lifted the earth from something probably to get rid of hum. As it only happens to you, then broad guess is your amp or somewhere in the vicinty.
May be something as simple as a dodgy/worn kettle lead you have plugged into your amp.
Happens a lot- and Ive seen someone get a major belter of a shock from it before, although thankfully not enough to kill them- although this has been known to happen!

I have a synth that came from the factory with an earth fault ( Cheetah MS6 for anyone that cares- no one told me it was a known fault ) and it F*CKING hurt when it gave me a mains shock a few weeks back, and made my hand swell up quite a bit. Lucky really.
Get it checked asap

ScoobyDoo555

aha cheetah ms6 In true fashion, it was a feature of the machine, not a fault!!

Had one and then a Matrix 1000

Dan

Freak

You open it up and look at the circuit board and on the slot labelled 'earth' on it is empty

I still have mine (bought from leeroy thornhill of prodigy/flightcrank fame no less ) - but Im scared to touch it

blubs

Phew, cheers guys!!

I'm not sure if it is real zap or static. Doesn't make a difference what footwear I've got on and it is enough to bring tears to my eyes (and thats before I start singing!!). Therefore I think it is zap.

We are using a RCD breaker and I have changed the mains lead from the amp for two brand new ones but the problem persists.

Some good advice here and I'll give my sparky mate a ring.

Since I posted this another friend mentioned about swopping first the guitar, then the amp with the lead guitarist from the band to eliminate each one. He is confident it is one of those two. We haven't lifted the earth to my knowledge but that is worth double checking.

Cheers All - Happy Strumming!

hedgehog

I feel that I should point out that attempting to locate a potentially deadly fault by a process of elimination could be a less than clever move, though it may indeed result in some elimination.

In order to avoid eliminating yourself I would suggest that you get someone who is knowledgable about such things to look at the gear before you next turn it on or plug it into the mains.

blubs

Indeed - er, good point.

Or I could take up the recorder?

(Or perhaps just call myself a taxi)..........blubs! You are a taxi!............

Looks like my Sparky mate will be attending next practice then!

I need a drink......

hedgehog

Yeah, take up the recorder!! Why didn't Jimi Hendrix think of that? He would have been such a big star if he'd gone the recorder route.

Actually one critic said that Hendrix bent the mains electricity to make music and I guess you are sort of taking this to its extreme!

Bubba po

It's not a "process of elimination" it's checking for common faults, through advice given by experienced, knowledgeable people with, in my case, 25 years of live band experience.

Bubba po

Blubs, if you are using an rcd then I don't think it can be mains zap.

In any case, reputable venues should have completely RCD-protected mains supply. Do you have a good relationship with your local music shop? In my experience, they are very happy to help out with this kind of problem. After all, a dead customer can't go on spending.

NotoriousREV

I think Hedgehog was referring to this bit:

Defensive bugger

Bubba po

Oops...

hedgehog

There is a lot of sense in this as if he were taking mains you'd expect the RCD to feel the imbalance and trip.

However, we don't know the full setup and so can't be sure. If, for example, there was somehow a neutral/earth problem with the mic so that the mic was actually connected to neutral rather than earth and if his guitar had the live on the signal earth then there would be no live/neutral imbalance if the gear was all fed from one RCD. Because neutral is tied to earth ultimately other members of the band may not get any kick under these circumstances.

Now, I know the exact picture above is highly unlikely for loads of reasons but because it is possible and because it has the potential to kill someone it is best to assume the worst and check things out.

In the end the real truth is likely to be something much more simple that none of us has thought of but I suppose we need a working theory to start with.

I'm still keen on the recorder idea myself, a simple solution that fits in with my hippie side.

Adrian F

Sounds like a piece of equipment you use has a poor earth connection and is allowing a section of screened equipment to "float" at a voltage high enough to give you a tingle.

As to PAT testing it i think that is a waste of time unless the electrician is use to working on sound equipment as he wont understand about what tests are suitable, probably more use to use a multi meter to measure the voltage difference between the Mic and the Guitar you use and see if there is one and then try and trace back where this earth fault is. also if you have a sparks as a friend ask him to check the RCD with a proper RCD tester that measure response times with different test currents. Also if the problem has only shown up in one venue ask him to earth loop test the power outlet you have used there.

This is not an uncommon problem as the lips are moist and make a good conductive contact point and being sensitive it doesnt take a lot of current to make you tingle, as said above these types of faults are potentially dangerous. The biggest problem for you to solve it is that normal electricians dont really understand sound systems and have no appreciation of why Musicians lift Earths and really see it as them playing Russian Roulette . could be a poor earth from the manufacturor not unknown with audio equipment. If this problem has occured in more than one venue then i would suggest you return the equipment to the shop where you puchased it and see if they can recreate the fault could be a lead with a broken screen or a loose earth terminal could be some thing else.

blubs

Thanks again for all the input.

I've only been practising with this new band for a month or so and we have only used the one practice venue - no gigs yet.

We are trying for a more suitable practice place for next Sunday so it might be interesting to see if it happens then.

I thought that by using the RCD and process of elimination, I might narrow down the offending item and be safe from a big enough zap to kill me. I'm starting to seriously worry for my health this Sunday!!

BTW, have gigged using various guitars/mikes/PA's/amps for years and never had this problem before.

I have since tried my daughters recorder and have managed to produce some high squeaks and a sound rather like an elephant being hit by a bazooka. (My children cried and the dog was sick too ).

ALi-B

iTrader: (1)

It is possible that the power supply in one of the amps or PA system used has a centre tapped transformer to create a "virtual earth" So no earthing on the mains is used. If there is a fault such as shorting coil or something as simple as a dry solder joint, it could well create such a problem. But as mentioned above, it needs someone who knows what they are looking at to trace the fault.

ru'

The first thing I'd check is the 3 pin mains plug - make sure some joker (I don't want to get into an earth loop discussion here) hasn't removed the earth lead connection at the plug end...

hedgehog

Hey, the man is now above earth loop discussions, he has moved on to the land of recorder where real rock and roll is taken to its limits by the big boys of the music business.

Play that funky recorder baby!

Vegescoob

Ah, my long ago live sound engineering days.
Anyway, the critical insight of children and animals must never be underestimated.

blubs

Even better than the recorder...I've discovered the hollow tom-tom!

You can go to any plug n play session and annoy the t1ts off the performing talents by slapping away offbeat to everything they play!

I've taken it to my recent pub crawl and had endless minutes of popularity mimicking Adam And The Ants tunes whilst nodding indulgently to the rest of the patrons and saying "Yeah?"

On the way home I simply turned it upside down and asked my friendly local kebab emporium person to fill it full of doner meat and chips!

Verily, a versatile instrument, come popularity increaser, come mobile plate.

I even put my beer soaked lips to the edge of it last night and no zap!!

BTW, my amp is being currently checked by an amp building techy friend. I'll let u know the outcome!

hedgehog

Why didn't I think of tom-toms! Where does this leave the recorder phase though? I was just getting into it and now you go moving to tom-toms. Call me confused but I'm not dealing well with this.

One other thing, check to make sure that there is no phantom power going to the mic (assuming it is a dynamic like a 58 or similar) as it is possible in strange circumstances to get a tingle off that though it will do you no real harm, best to eliminate the sources of real harm first.

It is good you are staying with the acoustic theme, now that I've thought about it, Bob Dylan had a nasty experience when he decided to go electric and it did him no favours.

blubs

Aha, you see - if you hold the recorder between your teeth you can blow as well as slap the Tom-Tom!

Did an accoustic gig last night near Oswestry with guys from work.

Twas great fun, three part harmonies, packed pub (100 or so and it's not big), and everyone really got into it.

No zapping this time through a different PA. Got practice on Sunday with the main band in a different location so hoping for a result.

Good fun doing the accoustic stuff again, much more relaxed and intimate. We have loads of little noise makers. tambourines, egg shakers, rasps and we pass them round the audience and get people to do mini 'solos'. It really seems to get people laughing.

Good times

hedgehog

I did an acoustic(ish) "show" back in the late 80s with a bunch of nutters. Some of the instruments were home made and little attention was paid to the persuit of musical excellence. One chap played a builders hod that we had strung up somehow so it made a sort of noise, though on reflection I don't remember it being a great noise. Anyhow during his "hod solo" he got the lighter fluid out and set it on fire in a scene similar to that seen at Jimi Hendrix gigs. I can only assume that Hendrix met with less draconian fire regulations in his day :-) It wasn't an altogether positive reception from some.

We also had a Buckfast bottle player who went on to drink the contents of his, errr, instruments and spend some time in hospital with alcohol poisoning.

In view of these experiences I am still keen you stick with the recorder, no good comes of a lot of other stuff.

NotoriousREV

I'm having difficulty with the middle 8 in "Pease Pudding Hot"

blubs

Hey! Acoustic is exactly what is says!

No-one mentioned aything about conventional instruments

The ultimate entertainer - the guy who can 'get up there' and ENTERTAIN - not show everyone that he can fast-fret for 3 hours and pose like a **** buddy!

We should form a band - bring your own DIY or trade device and 'play' it.

Like those guys who play the oil drums and stamp their feet, but much, much crapper (but more entertaining).