Electric shock from microphone

Discussion in 'The Sound Hound Lounge' started by Gonkboy, Jun 27, 2018.

  1. Gonkboy

    Gonkboy Member

    Sep 3, 2009
    Hi folks,

    I'm going to be playing at a bar this weekend and a band that played there a couple of weeks ago has warned us that the mics give us electric shocks.
    In the hope of avoiding this I have come here to ask for advice.
    I have a cheap Donner Active DI Box. It has a ground lift feature. I don't know if that helps or not.

    I'm pretty ignorant when it comes to electronics so any help would be great.

  2. ant_riv

    ant_riv Supporting Member

    Nov 10, 2006
    A shock from the mic usually indicates it’s connected to a system that is not properly grounded, also usually with another source.
    For example, the PA power not being properly grounded with a guitar amp.

    Before three-prong plugs, we used to have to test for shocks, by touching guitar strings and mic at the same time.
    If we got a shock, we would turn around one plug in the outlet, and that would usually cure the problem. Guitar and bass amps all needed to be tested this way to make sure the polarity was all the same.

    If everything in this club has three-prong plugs, either the ground is faulty in a piece of equipment, or the ground in the outlet(s) are faulty.

    CAUTION: An electric shock from what you are describing could KILL you. If you aren’t sure what the root cause is, or how to identify how to correct it, I wouldn’t recommend taking a chance with your life.
    DC1, willyboy, jens5 and 1 other person like this.
  3. johnkoz

    johnkoz Member

    Jul 29, 2008
    The Highland's of Northwestern NJ, USA
    foam mic cover
    T Dizz likes this.
  4. T Dizz

    T Dizz Member

    Jan 20, 2015
    Erotic City MN
  5. VaughnC

    VaughnC Supporting Member

    Jan 4, 2002
    While I don't care for wireless guitar systems, if I had enough mic shock problems I might consider one. But, these days, mic shocks are seldom an issue as most places have modern wiring.

    Probably the best thing to try is to make sure your PA and your guitar amp are connected to the same outlet...that way, if the outlet ground pin is connected to the power panel, both the guitar amp & PA will have the same ground. But, if the house outlet wiring is bad, it's wireless or flip a coin with the outlets.

    And, if you have a vintage amp, make sure it has a good/functioning 3 prong cord and the death cap removed.

    Of course, you could also check between your mic & guitar with a voltmeter to see how much potential difference there is between the two items...but that sounds over your head at this point.
    Last edited: Jun 27, 2018
  6. gtr777

    gtr777 Member

    May 30, 2005
    Long Island NY
    If you are going to "test" it by touching your strings and mic at the same time, touch the mic with the back of your hand!!

    Wireless and foam Mic cover can certainly help you out in this situation.
    monty and Flyin' Brian like this.
  7. RupertB

    RupertB Member

    Dec 11, 2003
    Raleigh, NC
    You can get a ground checker for less than $10 at any electronics or home improvement store. Get one & use it any time you play a new venue.

    I've taken 120v to the mouth once & plan never to do it again. I don't run my stuff through improperly wired receptacles. In one case, I ran a 50' extension cord to the other side of a venue to get to properly grounded service.

    The foam screen will help but don't solve the problem. Over a night of singing, water vapor from your breath can saturate it just enough to let current though.
    A wireless system will protect you, but doesn't help your band mates or protect your gear from damage due to bad electrical wiring.
    DC1 and rstites like this.
  8. frankie5fingers

    frankie5fingers Member

    Jan 16, 2009
    While an electric shock can hurt and even be dangerous, it's sometimes better than the shock you get from the mic when some people are singing through it.
  9. Darth Weller

    Darth Weller Member

    May 27, 2017
    Northern Virginia
    Sounds like someone is using a ground lift? I have that on a cab, and never use it, Ive seen a guy knocked to his feet liping a mic and I also had to watch a friend get electricuted on a power line once. I don;t srew with electricity, it will kill you very dead and put you through Hell as it does it. ( It cooks you, but real fast!)
  10. uab9253

    uab9253 Member

    Jul 20, 2017
    Mid Atlantic
    We did a party gig in a garage in the 80's - out in the country with nothing but two pronged outlets and we just let the third prong ride the floor in order to get our juice. Big mistake. The mic shocked me so bad, it was like someone punched me in the mouth and I almost fell down.

    He had no foam covers, and since the show must go on, we put condoms over the mics and did the gig. It was a bit odd with the nipples sticking up over the mic ball, but condoms were something everyone had an abundance of at an after prom party and so we went with it. People coming in thought it was deliberately part of our schtick.
  11. ned7flat5

    ned7flat5 Member

    Sep 21, 2014
    Melbourne Australia
    I carry one of these with me in my gig bag to check for stray AC voltage. When voltage is detected it flashes red and beeps. It’s also a torch. I run it over all the mics prior to soundchecking. About $20.

  12. jens5

    jens5 Silver Supporting Member

    Jan 7, 2017
    Still have a mark on my lip from lipping a mic and holding an electric guitar while on stage, years ago. About knocked me to my knee's. Bad ground or no ground. Don't mess with it. Check it out before hand.
  13. B Money

    B Money Member

    Jul 23, 2007
    Not a good solution. As already mentioned, the foam cover will quickly saturate with spit, restoring the conductive path from the mic to the singers lips.
    Using a wireless is a work around, although it really doesn't eliminate the problem it just avoids it.
  14. TubeStack

    TubeStack Supporting Member

    Jul 20, 2009
    Down At The Balinese
    This was happening at our rehearsal space, every time my mouth touched the mic. I became like a trained rat and learned how to sing without ever touching the mic, for years. :)

    However, eventually I Googled it and read something about making sure the guitar amp was plugged into the same outlet/wall as the PA system.

    It wasn’t (it was plugged into a different outlet/wall), so I did that, and haven’t had a problem since. I don’t know anything technical beyond that, though. :D
  15. jefesq

    jefesq Gold Supporting Member

    Sep 8, 2007
    the ocean state
    Keith Relf except guitar
    ant_riv and Angeln like this.
  16. rstites

    rstites Member

    Nov 27, 2016
    I always carry one of these in my gig bag, and check every outlet I'm going to be plugged into. Lots of bars were wired up by some dude who was paid with beer while he wired. I've played more than one place that had one circuit out of phase with the others. There's nothing so exciting as stepping up to the mic to find out that the PA is 180 degrees out of phase with your guitar amp - 120 V right through the mouth is more excitement than you really need! :)

    For more minor shocks, it's going to be due to poor grounding. In that case, all you can really do is put the wind screen on the mic and try not to slobber all over it too much.
  17. datguytim

    datguytim Supporting Member

    Feb 3, 2006
    Santa Monica, CA
    Don't take a chance. I got my bell RUNG - back in the '90s - once so hard I flew back into my amp & flat on my ass. Scary stuff, Italy's electrical wiring is notorious for this stuff, heads up to those who don't know.
  18. Saxon68

    Saxon68 Supporting Member

    Aug 30, 2017
    Using a wireless as workaround is ok till you have a band mate who thinks it’s cool to lay his head on you while singing backups as he’s playing bass. Man I got lit up so freaking bad and wasn’t expecting it as I’d been wireless for a couple years and was used to not getting hit anymore.
  19. explorer76

    explorer76 Member

    Jan 19, 2009
    Just make sure you are the SECOND band! :D :D
    MikeFM likes this.
  20. PBGas

    PBGas Supporting Member

    Jul 12, 2009
    Ontario, Canada
    Honestly, I didn't care for Wireless either....that is until I tried the Line6 G10. Fantastic unit and I can't tell a different if there is a cable or not. Trying the new Boss WL-50 system as well.

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