If a venue’s circuits are faulty or unbalanced, the amp isn’t in working order or you’re performing barefoot, you’re at risk for guitar-microphone electrocution
As an electrocution lawyer, I sometimes get asked about a particular scene in one of my favorite films, Cameron Crowe’s 2000 Oscar-winner “Almost Famous.” It’s the moment when Russell Hammond, the guitarist of the fictional ’70s rock band Stillwater, suffers what his bandmates believe is guitar-microphone electrocution during a concert, after touching the microphone stand.
This problem can stem from a few sources — or, more to the point, a few electricity feeds. And if you’re a guitarist, you’ll want to know about them to prevent guitar-microphone electrocution or other electrical injuries. (Here’s a video snippet of a guitarist who received burns on his hands after touching an ungrounded mic.)
Are you on the same circuit?
One way guitar-microphone electrocution can occur is if the guitar amplifier is plugged into an electrical outlet that’s on the stage, but the main sound console, to which the mic is grounded, is plugged into a different outlet in another part of the venue.
If these two power points are at vastly different ground voltages, a current can flow between the grounded mic’s housing and the grounded guitar strings. And if the guitar amp and the console are on different phases of the alternating current (AC) mains, things can get dangerous.
The solution? All of the instrument amps and audio gear should be running from the same AC distribution outlets. It means running a heavy extension cord from a stage outlet all the way to the mixing console (or vice versa). This is why you’ll often find a long, thick series of cables running from the stage to the sound mixing board at makeshift outdoor concerts (the kinds that aren’t in permanent amphitheaters).
Also, plugging all the power-cord ground pins into grounded outlets not only prevents shocks, it also reduces the humming sound often heard from amps. In addition, affixing a foam screen (also known as a windscreen) onto each vocal mic helps insulates guitarists from shocks.
How good is the venue’s power — or your amp’s wiring?
Another way guitar-microphone electrocution can happen is through faulty outlet wiring. Unbeknownst to a smalltime touring band, outlets at one venue could be on the same breaker but wired differently and not up to code.
It can be hard to tell how old wiring can be, or whether the venue owner even knows if a professional electrician installed it originally. An outlet might have 3-prong sockets, but that doesn’t mean it’s fully grounded.
My advice? Buy a circuit tester and bring it along to every venue. They range between $5 and $20 and can save a lot of hassle — and maybe even a musician’s life.
If you can’t find a circuit tester, or perhaps forgot to take it with you, there’s a simple way to test things out. Touch the mic stand with the neck of your plugged-in guitar so that the strings make contact with the stand. If a large blue arc is seen — like an arc welder had just fired up — don’t get anywhere near the mic.
The wiring on your amp also could be faulty, which prevents it from grounding correctly. If you’re getting little jolts and none of the above solutions work to stop them, take your amp to a professional amp repairman for an inspection. Never open up the amp casing to try and diagnose or fix it yourself.
Use common sense to avoid guitar-microphone electrocution
If you’re performing while barefoot or standing on a damp concrete floor, your risk for shock or electrocution is greatly increased. Also, if you’re playing outside on a metal stage and it starts raining, your shoes will get wet, making for an electricity conductor between your body and the stage. It’s a disaster waiting to happen.
One of rock ’n’ roll’s more infamous moments involving shock happened in December 1976, when KISS was performing in Lakeland, Florida. During the opening number, lead guitarist Ace Frehley touched an ungrounded metal staircase railing. The surge knocked him to the ground, rendering him unconscious.
Frehley recovered 30 minutes later and performed the rest of the concert, though he claimed to have lost feeling in his hand throughout it.
The incident also inspired him to write a song for the next KISS record. Its title?electric shock injuries, electrocution