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getting shocked by mics, help!

3/21/2005 3:31 AM
giustd	getting shocked by mics, help! at the gig last saturday my bass player was getting zapped every time his lip hit the mic. we changed the mic, the cable, and most importantly the outlet that his amp was plugged into, switching instead to the same outlet as the PA, no change, he still kept getting goosed. He uses some newer SS fender amp with a 3 prong plug, so I can't see how it'd be the amp. This same problem happened to me once at a gig a few months ago, I spent an hour later that week with the PA, amps and a meter. I couldn't reproduce the zap. very strange. Ideas, boys? This must be stopped!HELP!!!

3/21/2005 3:31 AM

giustd

getting shocked by mics, help!

at the gig last saturday my bass player was getting zapped every time his lip hit the mic. we changed the mic, the cable, and most importantly the outlet that his amp was plugged into, switching instead to the same outlet as the PA, no change, he still kept getting goosed. He uses some newer SS fender amp with a 3 prong plug, so I can't see how it'd be the amp.
This same problem happened to me once at a gig a few months ago, I spent an hour later that week with the PA, amps and a meter. I couldn't reproduce the zap. very strange.
Ideas, boys? This must be stopped!HELP!!!

3/21/2005 6:42 AM
SpeedRacer	#1 FOAM WINDSCREEN FOR MIC! Seriously. you can't always work around the wiring in some clubs. Downtown NYC for ex used to be DC in the old days and the older buildings which have not been renovated (read: clubs) have abysmal wiring. #2 It means the ground is either flipped or miswired. Easy way to tell (usually) is if you have that "buzz" on your guitar, alhtough with new amps that may not happen (don't know.. don't own any new amps. Some well meaning person may have completely screwed the pooch when they wired the outlets since in electronics black is ground and in home wiring it's hot.. Get one of those $5.99 "outlet checker" thingies at radioshack to show you what's up before you plug in . If something evil is going on, try plugging the PA and the guitarists stuff into the same outlet - so they share the issue (rather than having a potentially "complementary" wiring job..) And use the windscreen. It's far from perfect, but it does help. You can also wrap the mic in electrical tape (body) but that does not stop you from touching the screen on the end. . early morning rambling here. hope something made sense! There is almost nothing worse that getting 120V on your lips.. I've done that too and man that can hurt!

3/21/2005 6:42 AM

SpeedRacer

#1 FOAM WINDSCREEN FOR MIC!

Seriously. you can't always work around the wiring in some clubs. Downtown NYC for ex used to be DC in the old days and the older buildings which have not been renovated (read: clubs) have abysmal wiring.

#2 It means the ground is either flipped or miswired. Easy way to tell (usually) is if you have that "buzz" on your guitar, alhtough with new amps that may not happen (don't know.. don't own any new amps.

Some well meaning person may have completely screwed the pooch when they wired the outlets since in electronics black is ground and in home wiring it's hot.. Get one of those $5.99 "outlet checker" thingies at radioshack to show you what's up before you plug in . If something evil is going on, try plugging the PA and the guitarists stuff into the same outlet - so they share the issue (rather than having a potentially "complementary" wiring job..)

And use the windscreen. It's far from perfect, but it does help. You can also wrap the mic in electrical tape (body) but that does not stop you from touching the screen on the end. .

early morning rambling here. hope something made sense!

There is almost nothing worse that getting 120V on your lips.. I've done that too and man that can hurt!

3/21/2005 7:26 AM
giustd	"#1 FOAM WINDSCREEN FOR MIC!" >>>yeah, good suggestion Speed, cheap, quick easy way to isolate especially when ya don't know what condition the ac is your'e plugging in to. " you can't always work around the wiring in some clubs." >>>true. It means the ground is either flipped or miswired. >>>which is a bit of a mystery cuz he's never had a problem before and its a (relatively) new amp with a 3 pronger. Get one of those $5.99 "outlet checker" thingies at radioshack to show you what's up before you plug in . >>>i have one ta home and I'm gonna start bringing it and checking the ac just for peice of mind. the question is what to do if its wrong!? put that windscreen on! If something evil is going on, try plugging the PA and the guitarists stuff into the same outlet - so they share the issue >>>did that, or more accurately plugged him into the second of the double outlet on the wll, with the rest of the band (including PA) plugged into the first. typically those 2 plug outlets are hard wired together. And use the windscreen. It's far from perfect, but it does help. >>I'm on that. There is almost nothing worse that getting 120V on your lips.. I've done that too and man that can hurt! >>>especially at a gig, makes you gun shy to really get up there and sing. I wanna make sure this doesn't ahppen again to anyone in the band, especially me!

3/21/2005 7:26 AM

giustd

"#1 FOAM WINDSCREEN FOR MIC!"
>>>yeah, good suggestion Speed, cheap, quick easy way to isolate especially when ya don't know what condition the ac is your'e plugging in to.

" you can't always work around the wiring in some clubs."
>>>true.

It means the ground is either flipped or miswired.
>>>which is a bit of a mystery cuz he's never had a problem before and its a (relatively) new amp with a 3 pronger.

Get one of those $5.99 "outlet checker" thingies at radioshack to show you what's up before you plug in .
>>>i have one ta home and I'm gonna start bringing it and checking the ac just for peice of mind. the question is what to do if its wrong!? put that windscreen on!

If something evil is going on, try plugging the PA and the guitarists stuff into the same outlet - so they share the issue
>>>did that, or more accurately plugged him into the second of the double outlet on the wll, with the rest of the band (including PA) plugged into the first. typically those 2 plug outlets are hard wired together.

And use the windscreen. It's far from perfect, but it does help.
>>I'm on that.

There is almost nothing worse that getting 120V on your lips.. I've done that too and man that can hurt!
>>>especially at a gig, makes you gun shy to really get up there and sing. I wanna make sure this doesn't ahppen again to anyone in the band, especially me!

3/21/2005 10:19 AM
John Fisher	I don't know what the Radio shack thing is but a good thing to have is a little tester screw driver. I don't know what they are called in English but it is basically a tranparent screwdriver with a neon light and a resistor in it. If anything you touch has more then about 50 volts in it, it will light up. Living in South America for years this is a common problem when doing shows out in public and nothing is wired correctly. If you have 3 things plugged in and just one of them is not right, you will have that problem since they are all hooked to the same ground or chasis. I would test each piece of equipment one by one plugging them in seperatly and using the tester screwdriver to make sure nothing lets the light go on when touching the chasis. If one thing would light the screwdriver up I would switch the plug around on that thing. You can use your digital multitester also for this by holding one test lead in your hand or to anything thats a ground like a water pipe or whatever and touch the chasis with the other prong. If you get a voltage reading then you have to switch the plug around. Don't get shocked!!!! John Fisher

3/21/2005 10:19 AM

John Fisher

I don't know what the Radio shack thing is but a good thing to have is a little tester screw driver. I don't know what they are called in English but it is basically a tranparent screwdriver with a neon light and a resistor in it. If anything you touch has more then about 50 volts in it, it will light up.
Living in South America for years this is a common problem when doing shows out in public and nothing is wired correctly.
If you have 3 things plugged in and just one of them is not right, you will have that problem since they are all hooked to the same ground or chasis.
I would test each piece of equipment one by one plugging them in seperatly and using the tester screwdriver to make sure nothing lets the light go on when touching the chasis. If one thing would light the screwdriver up I would switch the plug around on that thing.
You can use your digital multitester also for this by holding one test lead in your hand or to anything thats a ground like a water pipe or whatever and touch the chasis with the other prong. If you get a voltage reading then you have to switch the plug around.
Don't get shocked!!!!
John Fisher

3/21/2005 12:01 PM

jaysg

quote:
"I don't know what the Radio shack thing is"

S/b available at any hardware store - molded plug for whatever country, three LEDs that light up in a number of patterns indicating whether the socket is good or which line is not - for instance missing ground or reversed Hot/Cold, etc. I also have an older two prong device which is pretty much just a neon bulb with pointy crampons. You can shove it into a socket to make sure cold is cold & hot is hot, or hold it between your guitar strings and the mike you're going to use.

3/21/2005 1:18 PM
bob p	i did a quick google for "outlet tester" and found no shortage of hits. here's a picture of a typical device for a USA-spec outlet: http://dlsus.chainreactionweb.com/catalog/product_info.php?products_id=474 you can accomplish the same test with a wiggie. if you get volts between the neutral and ground wires you know that you've got a polarity reversal problem. granted, the wiggie approach is harder to use after a few beers. in that situation, a pocket tester is just the ticket. fwiw, i would refuse to play at any club that has unsafe wiring. does anyone bother to haul a line isolation transformer to their gigs?

3/21/2005 1:18 PM

bob p

i did a quick google for "outlet tester" and found no shortage of hits. here's a picture of a typical device for a USA-spec outlet:

http://dlsus.chainreactionweb.com/catalog/product_info.php?products_id=474

you can accomplish the same test with a wiggie. if you get volts between the neutral and ground wires you know that you've got a polarity reversal problem. granted, the wiggie approach is harder to use after a few beers. in that situation, a pocket tester is just the ticket.

fwiw, i would refuse to play at any club that has unsafe wiring.

does anyone bother to haul a line isolation transformer to their gigs?

3/21/2005 1:26 PM
bob p	http://www.aemc.com/products/pdf/2121.03.pdf

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