Shock From Microphone

gubble

Morning All

Wondering if you could help.

Played a gig on Friday at a new venue night and as per the norm we ran 3 vocal mics through the PA. We normally don't run anything else through it and this is was no exception.

Each of us were getting a small electric shock if our lips touched the mics. Having done literally hundreds of gigs with this PA this is something I've never had before.

What could be going on here? I'm assuming it's some kind of grounding issue . With this never happening before is it possible it's an issue with the venue's electrics rather than something up with our equipment?

Sporky

PA plugged into the same socket as your backline/effects?

gubble

Twin Socket on the wall:

Left Hand Socket - Fender Hot Rod Deluxe

Right Hand Socket - 4 Way Adapater with PA Powered Mixer, Pedalboard, IEM Transmitter, A Single Light

All other equipement (bass rig and lighting rig) were in another twin socket on the other side of the room

Quite often run the HRD and the PA off the same 4 way and have never experienced this before.

Jalapeno

Sounds like some dodgy wiring - we got this once when we practiced at a cricket club (in winter) - there was a 4 way extension that had Negative wired to Earth !

paul_c2

It could be you're building up static electricity on your body, then discharging it to ground when you touch the mic.

ESBlonde

This indicates the earth circuit is incorrect somewhere and the stray voltage is running from one system to the other via your wet lips.
Buy and always use and RCD with all devices. Buy and use a mains socket tester. Both of these are less than £10 from DIY shops or cheaper online and could/will save your life. Could it be the extension lead you have has gone suspect?
Open it up and look in the plug and sockets. Also look in the plug of the PA amplifier/mixer.

Sporky

I would think that a small shock - at a guess a hefty tingle? - is probably down to different ground potential at each socket, rather than cross wiring which'd give you a full-on belt.

Moe_Zambeek

The rehearsal place we use has one particular mic cable that does this to me. Could your mic cable be on the fritz?

gubble

Happened on all 3 Microphones.

& yes only a tingle - bit like someone pulling at your moutstache hair.

maltingsaudio

ESBlonde said:

This indicates the earth circuit is incorrect somewhere and the stray voltage is running from one system to the other via your wet lips.
Buy and always use and RCD with all devices. Buy and use a mains socket tester. Both of these are less than £10 from DIY shops or cheaper online and could/will save your life. Could it be the extension lead you have has gone suspect?
Open it up and look in the plug and sockets. Also look in the plug of the PA amplifier/mixer.

What he said ! worthwhile spending an afternoon opening all your plugs and checking and tightening all terminals, you will be amazed at how many have worn loose.