Why is my microphone shocking me

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. 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.

I run it over all the mics prior to soundchecking. 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. B Money Member. Messages 6, TubeStack Silver Supporting Member. Messages 11, 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. RupertB said:. Don't take a chance. Follow the power cables to the outlets and make sure all plugs have three prongs.

Whenever you touch your face to the mic and your hand to the guitar strings, you are completing a circuit and the result is pretty rough. The solution? Ditch any two-prong cords and replace them with grounded three prong cables at every outlet. Not an option? Use a pop screen on the mic as a quick fix a coat-hanger and tights can do the trick in a pinch. Although you may feel safely isolated from the electrical components of your guitar amplifier or mixer, this is not the case.

Even while standing several feet away from these devices, you are still directly connected to them through the guitar or microphone in your hand. Just as the chassis of the amplifier and mixer are connected to ground, so are the hardware of your guitar and the grill of your microphone. The bridge of your guitar is connected to the sleeve, or shield, of your instrument cable.

The sleeve of your cable also connects to the amplifier chassis. Therefore anything that is metal and touching the bridge is connected, too. Your tremolo bar, tail piece, strings, and tuners are all directly wired to the chassis of your guitar amp. The grill of your microphone is connected to pin 1 ground of your XLR microphone cable. This is a direct connection to the chassis of your microphone preamp, or mixer.

There is no need to be concerned by these connections. When functioning properly, these connections are actually a safety measure, in place to allow voltage to find a pathway to ground. When your equipment is not properly grounded, however, these safety measures become a safety hazard.

The capacitance of the human body is relatively limited, maxing out around pf, or pico-farads. In the following equation, you can see that the maximum charge an object can store is limited by its capacitance. When you touch a guitar or microphone that is connected to an ungrounded system, the voltage on the chassis of that system will be transferred to you.

If you are not touching another conductive surface, the voltage will be stored to your body as electric charge. The situation becomes dangerous when you simultaneously touch both the ungrounded equipment and a grounded surface, creating a conductive pathway from the ungrounded equipment to ground. When you walk on a carpeted floor, your body can become charged. This can be somewhat painful, but is not life threatening.

The same thing is true for musical equipment. When you pick up an instrument connected to ungrounded equipment, any voltage on the chassis will be transferred to your skin. Voltages within the circuits of various amplifiers range widely, but typically range from a few millivolts to V. Due to the low capacitance of your body, charges from these devices are very low. If you set the instrument down and then touch a grounded surface, the charge on your body may be so small that you do not even feel the discharge.

The issue, then, is when you touch a microphone and the strings or any other conductive part of the guitar at the same time.

In this scenario, the stray voltage from the ungrounded guitar amp would flow through you into the microphone and then to the mixing console, AC mains, and ultimately a ground somewhere. To make things worse, your lips are typically the first point of contact with the microphone. Often we believe all our equipment is properly grounded, but the power mains have different ground potentials.

If any of the AC power outlets are wired with different ground potentials, there is a likelihood that there will be shock hazards with the audio equipment. In these situations, electricity will flow from higher potential to lower potential.

Therefore, if socket grounds have a difference in potential, electricity will flow to whichever ground is lower. In this case, if we were to touch the guitar strings and microphone simultaneously, we would create the electrical connection and the voltage would flow to the lower ground potential.

This may very well result in a shock, particularly if there is a significant difference between the socket ground potentials. I would always suggest that you test the power outlets of any new room you plug into. We can easily test our outlets with an inexpensive receptacle tester. If you have a discrepancy between power outlet ground potentials, a common strategy is to plug all equipment into one socket to ensure a common ground. Use a power bar if need be.

This dangerous situation requires fixing. Get your audio equipment inspected by a qualified technician and get a qualified electrician to fix the AC outlets. Electric shocks happen when a sufficient current at a high enough voltage travels through our bodies.

Notice that the electricity must travel through our bodies and not just be present in our bodies. This is why we can often avoid shocks in faulty systems up to the point where we touch a microphone and close a circuit, allowing electricity to travel through us.