Quantcast
zapped on stage .touching guitar strings and mike.how come? - Gearspace.com
The No.1 Website for Pro Audio
zapped on stage .touching guitar strings and mike.how come?
Old 17th November 2009
  #1
Lives for gear
 
1 Review written
🎧 15 years
zapped on stage .touching guitar strings and mike.how come?

It didn`t happen to me, but why does this happens to people on stage? I read something about floating ground but it`s hard to grab. can someone explaine?

Is this also another good reason for using wireless guitars on stage?

thanks
Old 17th November 2009
  #2
Gear Maniac
 
🎧 10 years
There is NO good reason for using wireless guitars on stage.
Old 17th November 2009 | Show parent
  #3
Lives for gear
 
surflounge's Avatar
 
🎧 15 years
important to stand barefoot in the rain while you are zapped until you understand about GROUNDING
Old 17th November 2009 | Show parent
  #4
Lives for gear
 
Enginearing's Avatar
 
🎧 10 years
I've seen this happen with someone running backline off a powersupply without ground. basically the mic (and its grounded path via console etc) becomes the electric guitar's grounding potential (via the performer). It can happen if there is a too much difference in ground voltage between stage/monitors. (the zap is basically a small levelling current).

this alone is a very good reason to run off properly set up equipment.

oh and there IS a recent thread with info here...
Old 17th November 2009 | Show parent
  #5
Gear Guru
It happens because electric guitar manufacturers want you to die!

Why OSHA has never taken on the deadly string ground problem is truly strange. Why the EU CE hasn't is even weirder as those Eurocrats want to regulate your feces.

You can fix it yourself with a 5 cent capacitor.

Disconnect the string ground that connects the bridge to the internal ground of the guitar's electronics. Connect a .022 uf 250 volt cap in series with that string ground wire and the guitar's internal ground.

Problem solved, you will live to play another day!

Meanwhile, have a good laugh when the other guy gets zapped across the stage and ends up with a blister on his lip! I find that increasingly hilarious as I age.

Jim Williams
Audio Upgrades
Old 17th November 2009 | Show parent
  #6
Lives for gear
 
gremlin moon's Avatar
 
🎧 10 years
It happened to the Grateful Dead at Woodstock and it effected their playing so much that they took themselves out of the movie. Maybe we'll save that story for the "Do Drugs and Electricity Mix" thread . . .
Old 19th November 2009 | Show parent
  #7
Lives for gear
 
1 Review written
🎧 15 years
thanks

so this will only hapen if: either ground is disconnected from the guitar amp or from the PA system? If i test the mic and strings with a multimeter. what voltage will normally show if ther is a problem?

Will there be any problems if hot and neutral are reversed? I`ve been told that this will cause no harm.hmm...

great info
Old 19th November 2009 | Show parent
  #8
Lives for gear
 
rkopald's Avatar
 
2 Reviews written
🎧 10 years
Quote:
Originally Posted by Jim Williams ➑️
It happens because electric guitar manufacturers want you to die!

Why OSHA has never taken on the deadly string ground problem is truly strange. Why the EU CE hasn't is even weirder as those Eurocrats want to regulate your feces.

You can fix it yourself with a 5 cent capacitor.

Disconnect the string ground that connects the bridge to the internal ground of the guitar's electronics. Connect a .022 uf 250 volt cap in series with that string ground wire and the guitar's internal ground.

Problem solved, you will live to play another day!

Meanwhile, have a good laugh when the other guy gets zapped across the stage and ends up with a blister on his lip! I find that increasingly hilarious as I age.

Jim Williams
Audio Upgrades
That's a really good idea.
Old 20th November 2009 | Show parent
  #9
Here for the gear
 
🎧 10 years
Quote:
Originally Posted by musicmixer04 ➑️
thanks

so this will only hapen if: either ground is disconnected from the guitar amp or from the PA system? If i test the mic and strings with a multimeter. what voltage will normally show if ther is a problem?

Will there be any problems if hot and neutral are reversed? I`ve been told that this will cause no harm.hmm...

great info
It also can happen if one of the outlets is miswired.
If measured with a meter (on AC volts setting) a perfectly grounded system would read zero volts. That almost never is the case in the real world, but I would be suspect of anything more than a few volts. Usually if there's a problem you'll see 50-120vac.

If the amp on stage is ungrounded, you can usually flip the ground switch on the amp, but keep in mind this sometimes makes the problem worse. When I played regularly I ALWAYS carried a DMM with me to test the mic to string voltage before stepping up to the mic.
Old 20th November 2009 | Show parent
  #10
Gear Addict
 
Wilburguy's Avatar
 
🎧 15 years
This is due to a voltage potential between the grounds of the house pa and the power the guitar amp is plugged into. In a well designed club system the house PA and stage power must be run on a common ground.

While it is not safe to lift the ground on anything, lifting the ground on your amp would prevent this particular problem.
Old 20th November 2009 | Show parent
  #11
Gear Guru
Quote:
Originally Posted by Wilburguy ➑️
This is due to a voltage potential between the grounds of the house pa and the power the guitar amp is plugged into. In a well designed club system the house PA and stage power must be run on a common ground.

While it is not safe to lift the ground on anything, lifting the ground on your amp would prevent this particular problem.
Danger! Will Robinson! Don't do that. Many amps require "earthing" like Marshalls. They even have a warning on the back that reads "This device MUST be earthed". Lift it and YOU are the lethal discharge path to earth.

Don't bother with meters, things can change during a show. Just put the cap in, stay alive.

Got 5 cents?

Jim Williams
Audio Upgrades
Old 20th November 2009 | Show parent
  #12
Lives for gear
 
Lenzo's Avatar
 
6 Reviews written
🎧 10 years
I was zapped once and saw those little cartoon stars circling around my head...I thought that was only in cartoons, but not so.
L.
Old 20th November 2009 | Show parent
  #13
Gear Addict
 
🎧 10 years
one cool thing about an sm57 is that the grill does not seem to be in contact (electrically) with the body of the mic. in situations where i'm getting zapped, i find the sm57 to be preferrable to the foam windscreen things.

the body of the mic will still be hot so you'll need to be careful there...but if it's just a little annoying zap, it can help you get through a show.
Old 20th November 2009 | Show parent
  #14
Gear Guru
Quote:
Originally Posted by Lenzo ➑️
I was zapped once and saw those little cartoon stars circling around my head...I thought that was only in cartoons, but not so.
L.
Remember when you came too, that guy in the corner laughing his ass off?

That was ME!

Jim Williams
Audio Upgrades
Old 20th November 2009 | Show parent
  #15
Registered User
 
🎧 10 years
Quote:
Originally Posted by spandex man ➑️
There is NO good reason for using wireless guitars on stage.
spoken by someone who has multiple problems.

1. inexperience with quality wireless equipment

2. lack of understanding of wireless and its assistance with two key safety issues ie: grounding and trip hazards.

3. the inability to formulate a sentence which address the subject at hand and explains their reasoning behind their comments.


UTTER FAIL
Old 20th November 2009 | Show parent
  #16
Old 20th November 2009 | Show parent
  #17
Lives for gear
 
🎧 10 years
Didn't the beatles play in the rain and some guy out the back was told to pull the mains if he saw one of them getting shocked.
Old 3rd July 2012 | Show parent
  #18
Gear Addict
 
1 Review written
🎧 10 years
Quote:
Originally Posted by Wilburguy ➑️
This is due to a voltage potential between the grounds of the house pa and the power the guitar amp is plugged into. In a well designed club system the house PA and stage power must be run on a common ground.

While it is not safe to lift the ground on anything, lifting the ground on your amp would prevent this particular problem.
Boy oh boy, my Fender Deluxe must really be screwed up because it has no ground, only a line and a neutral on the power cable yet I still got shocked pretty badly once.

However, reversing the phase of the input power did solve the problem this particular time.
Old 3rd July 2012
  #19
Lives for gear
 
Johnny Favorite's Avatar
 
🎧 10 years
I got shocked. Lots of times. I grab my guitar, put the pickups almost touching the mic. If I hear any crackling or see tiny sparks, I ain`t touching that mic untill I solve the problem. Sometimes it`s a bitch. Wireless saves precious time.
Old 3rd July 2012
  #20
Lives for gear
 
🎧 10 years
Before we played, I checked for voltage differences between the guitar and mic with a voltmeter. We wouldn't perform until it was corrected.

And NEVER lift the ground on an amplifier!
Old 9th July 2012 | Show parent
  #21
Gear Guru
Quote:
Originally Posted by pultech ➑️
Boy oh boy, my Fender Deluxe must really be screwed up because it has no ground, only a line and a neutral on the power cable yet I still got shocked pretty badly once.

However, reversing the phase of the input power did solve the problem this particular time.
Maybe you were lucky? Best to play it safe. Beats dying.

I installed a 3 conductor grounded power cable in my 1966 Deluxe Reverb amp. I grounded the ground wire to the chassis. Next, I removed the 2 way ground switch and installed a 3 way center-off power toggle switch. That way it's usually set to the center = off position. If I'm out in some 100 year old house with obsolete 2 conductor wiring, I can switch that ground both ways like the original.

I found dying is bad for repeat business.
Old 9th July 2012 | Show parent
  #22
Lives for gear
 
Boschen's Avatar
 
🎧 10 years
Quote:
Originally Posted by supercomet32 ➑️
spoken by someone who has multiple problems.

1. inexperience with quality wireless equipment

2. lack of understanding of wireless and its assistance with two key safety issues ie: grounding and trip hazards.

3. the inability to formulate a sentence which address the subject at hand and explains their reasoning behind their comments.


UTTER FAIL
Pretty much my thought too, but don't sugar coat it; give it to him straight.

I carry a simple LED plug checker. Problem is, you have to check the feed to the stage and to the PA. If it's house PA, this can be an issue of access.
I've found all kinds of odd AC wiring issues in venues; it's unfortunately quite common in smaller places; but that's not to say that that big boys never get safety issues dead wrong either.... stage collapse, anyone?

Protect yourself; install the cap Jim mentions. In fact, there should be a sticky thread on that very subject, with detailed how-to and photos. Maybe next time I open up one of my beater axes...
Old 9th July 2012 | Show parent
  #23
Gear Addict
 
1 Review written
🎧 10 years
Quote:
Originally Posted by Jim Williams ➑️
Maybe you were lucky? Best to play it safe. Beats dying.

I installed a 3 conductor grounded power cable in my 1966 Deluxe Reverb amp. I grounded the ground wire to the chassis. Next, I removed the 2 way ground switch and installed a 3 way center-off power toggle switch. That way it's usually set to the center = off position. If I'm out in some 100 year old house with obsolete 2 conductor wiring, I can switch that ground both ways like the original.

I found dying is bad for repeat business.
Shucks Jim,
Where's your sense of adventure?

I hang little neon bulbs in my hair and if I am building a decent charge, they light up warning me that I am already in pain

Does the cap on the instrument ground cause anymreduction in hum cancellation?

Thanks,

John Chase
Old 9th July 2012 | Show parent
  #24
Lives for gear
 
🎧 10 years
Quote:
Originally Posted by Jim Williams ➑️
Maybe you were lucky? Best to play it safe. Beats dying.

I installed a 3 conductor grounded power cable in my 1966 Deluxe Reverb amp. I grounded the ground wire to the chassis. Next, I removed the 2 way ground switch and installed a 3 way center-off power toggle switch. That way it's usually set to the center = off position. If I'm out in some 100 year old house with obsolete 2 conductor wiring, I can switch that ground both ways like the original.

I found dying is bad for repeat business.
Very true.

Have an amp tech replace your ungrounded power cable with a real 3-prong cable. Have them disconnect the ground switch and "death cap" and wire it like you would in this decade.

While the tech is at it, have them replace your filter capacitors -- they're way past due if they've never been changed. While the filter caps may not shock you, if they go, you're not going to like what happens downstream of them...
Old 9th July 2012 | Show parent
  #25
Gear Guru
Quote:
Originally Posted by pultech ➑️
Shucks Jim,
Where's your sense of adventure?
I lost that back in 1979 when I touched the center tap on a Musicman HD130 amp. 750 volts can either cure or kill you.
Old 9th July 2012 | Show parent
  #26
Gear Addict
 
1 Review written
🎧 10 years
Quote:
Originally Posted by Jim Williams ➑️
I lost that back in 1979 when I touched the center tap on a Musicman HD130 amp. 750 volts can either cure or kill you.
That explains the long nose and curly hair...
I just thought you were a fellow Jew, lol.
Old 10th July 2012
  #27
Lives for gear
 
🎧 10 years
Back in the day of barefoot in the carport, we would leave the guitars or mics unplugged but with the cable plugged in. Turn them up fairly loud and flip the power switch with a drumstick. Once the amp warmed up and started humming, we'd use the drumstick to flip the ground back and forth to see which way had less hum. At that point it was safe to hit the standby, plug things in and start playing. We were basically setting everyone's amps so that the neutral was on the chassis side, or the ground of the guitar.

Another thing is the brush the mic with the back of your hand before kissing it (and having it kiss you back!). That at if you do get a shock, your hand will jerk away from the mic instead of your fingers trying to close around it.

You can get a tingle if the is leakage on the neutral and poor ground connections. The ground is supposed to be there as a way to drain away any faults such as a poor or failed neutral connection. Never break the AC ground connection. Lift a signal ground if you have to but keep that safety ground there.
Old 10th July 2012 | Show parent
  #28
Lives for gear
 
🎧 10 years
Quote:
Originally Posted by Jim Williams ➑️
I lost that back in 1979 when I touched the center tap on a Musicman HD130 amp. 750 volts can either cure or kill you.
<humour>

There's an easy remedy for that. Simply reverse the phase, touch it again, and you're back to your old self.

</humour>

You think that's bad - try touching the yoke on the picture tube of a scope or TV. There's 20,000-40,000 volts there. I know one guy who did that - he walked away cursing like a munchkin.
Old 10th July 2012 | Show parent
  #29
Gear Nut
 
hosehead's Avatar
 
🎧 5 years
I was playing a Travis Bean bass at the Boot & Saddle in Philadelphia, plugged into a back. During a sound check I came close to the mic and completed the circuit. I remember getting close, then I remember seeing the ceiling, a good 5-feet from where I was standing.

I carry a ground-tester in the gig-bag since then, and I have caused a ruckus when I have found dodgy wiring at venues. I hate the be the pain in the ass, but I am a fan of breathing.
Old 10th July 2012
  #30
Gear Addict
 
Yann Leon's Avatar
 
🎧 5 years
Happened to me too. My mouth had been zapped. Not fun...

I can't explain why, but everytime it happens there are some conditions :

1) It is a rainy day,
2) Seems that the are no working ground on the power bar ,
3) it is a crapy place which smells bad.. "neonified" and buzzing.
4) Too many things plugged in the power bar: amps, 14 pedals, bass amp, pals's amps and 14 more pedals.
5) The beer isn't free
πŸ“ Reply

Similar Threads

Thread / Thread Starter Replies / Views Last Post
replies: 1178 views: 265250
Avatar for bill5
bill5 2 weeks ago
replies: 60 views: 8157
Avatar for bonnybilly
bonnybilly 11th July 2009
Post Reply

Welcome to the Gearspace Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…

Forum Jump
Forum Jump