hags2k Posted July 2, 2003 Share Posted July 2, 2003 Well, an interesting thing happened to me earlier today during rehearsal. I was practicing with the guys in my garage earlier, and we'd just rearranged things and cleaned things up a bit, including checking the wiring in the garage and making sure we didn't overload the circuits in it (it's quite an old garage that was wired by a two year old, it seems). We always plug into surge protectors that are very nice and insured, as a precaution, and we've blown the breakers in our surge protectors before. So, we got everything situated, but today I encountered something I'd never encountered before. While playing, I got up on my mic and my lips made contact with it. When that happened, I noticed a sharp pain. I thought it was my imagination, but then it happened again, and I realized that the pain was something like when you touch your lips or tongue to a battery: a mild electric shock. I was concerned, but when I had a friend try the mic, he didn't notice any problem, so I was about ready to dismiss it again (novice mistakes here, I know). Then my amp started to go a little crazy. My volume dropped to nothing and then got loud enough to clip the preamp, and then dropped again. It leveled off and was fine, though, right before I disconnected it and everything attached to it. After going back and rechecking all our electrical connections, I realized that someone had plugged one of the surge protectors into an extension cord using a 3-prong to 2-prong adapter, thus negating the ground connection. I am pretty sure that this is what was causing this phenomenon. I've not encountered a serious electrical issue before, however, so I was wondering if any of you experienced types out there could, based on my description, confirm my hypothesis. Also, if any of you thing there might be permanent damage to any of my equipment, I would appreciate that, as well. Everything seems to be working fine, though, and even if the ungrounded connection to the outlet was not the cause, it was still a problem. So, any thoughts? unkownroadband.com - step into the unkown :-) Link to comment Share on other sites More sharing options...
fantasticsound Posted July 2, 2003 Share Posted July 2, 2003 Yes, that's the result of a floating ground. When you made contact with the mic (and I'm guessing, the strings of your bass, simultaneously) you became the path to ground! Very Bad. Most of us have been shocked that way, if you play an electric instrument and sing, but I wouldn't recommend it. I had a loose wire in a quad box get shaken from it's connection, when the acoustic guitar player's amp, leaning against the drum riser, vibrated until it fell against said quad box. Everyone after that quad received a 117 volt shock when they went to sing. The lead guitarist was hit worst. Knocked him down. The front man, a fiddle player, was using a wireless pickup on his fiddle. But he has a habit of wrapping his pinky around the base of the volume pot mounted on the instrument, and he burned the finger a bit. Somehow, none of this destroyed anything on the keyboard player's rig. (Whew!) I was mixing.... imagine my surprise when, in a ballroom filled with several thousand people, the band just stopped, mid-song. Stopped the show for 20 minutes while Opryland Hotel's engineering dept. inspected the situation, to discover exactly what I already knew to be true. The moral... don't play unless you're properly grounded. If you must plug into a two prong outlet, use a 3 prong to 2 prong adapter and tie the ground wire to ground!! It's easiest to find me on Facebook. Neil Bergman Soundclick fntstcsnd Link to comment Share on other sites More sharing options...
PhilMan99 Posted July 2, 2003 Share Posted July 2, 2003 Ground-loop. Try this: http://www.ebtechaudio.com/he-2des.htm Although specifically designed for "line-level" signals to eliminate buzz/hum, it works fine with the output of the average stomp-box or rack-mount effects. Definately signal-loss (volume reduction) plugging bass (or guitar) directly into it, though. Alternatively "live with it". Link to comment Share on other sites More sharing options...
BenLoy Posted July 2, 2003 Share Posted July 2, 2003 Your amp's ground being defeated is exactly what caused you to get shocked by the microphone. Every time you get close to the microphone, you'll ground yourself through your mouth! Not good. Never EVER play through an amp that isn't grounded. You can get some really scary shocks that way, even if you're not using a microphone. If you HAVE to plug into a non-grounded outlet, bring one of those grounding pin defeaters you mentioned, but USE THE METAL GROUNDING TAB ON IT! Tie a piece of bare wire to that little tab and then find a piece of metal that's going into the ground and attach the wire to it. Too many people use that device as a way to defeat grounded plugs without realizing what they've been designe for in the first place. ALWAYS GROUND YOURSELF! Link to comment Share on other sites More sharing options...
davebrownbass Posted July 2, 2003 Share Posted July 2, 2003 If I'm not mistaken, people have died this way. Well, at least in the movies. And the problem is worse with tube amps, I believe...all that current surging through those copper veins. By the way, a lot of tube amps have 2 way on switches to reverse ground. A lot of Peavey amps have that too. So, here's my grounding story. One year, at the college where I now teach bass, I brought an old Peavey tube guitar combo, 4 tubes and an open back 6x8 speaker config. Tweed covering. Very cool. So I had my bass plugged into this beast and a young student came in, really proud of his guitar, which was plugged into a Fender Twin. And he wanted me to check it out...nice American Strat...a bit vintage. So he said here, and handed it to me. While I was holding my arm against my bass strings. I took the guitar and the current surged through my veins. I screamed in horror and... SPIKED HIS GUITAR TO THE FLOOR. Just like Michael Irvin. He screamed "My guitar" just like Neil at Woodstock. And he picked it up and inspected it. It was okay. By this time, I had taken my bass off, and looked it over. Then, I picked up my bass. No harm done. He said, "Okay, look at it now." And he handed me his guitar while I handed him my bass (old Aria Pro II I used to have) And...I spiked BOTH instruments. Still no harm done...but I learned forever. Do not mess with amp grounding. "Let's raise the level of this conversation" -- Jeremy Cohen, in the Picasso Thread. Still spendin' that political capital far faster than I can earn it...stretched way out on a limb here and looking for a better interest rate. Link to comment Share on other sites More sharing options...
jeremy c Posted July 2, 2003 Share Posted July 2, 2003 The bass player for an Irish band called Stone the Crows died on stage of electrocution. Keith Richard was knocked unconscious at a show in San Francisco in the '60s. If I ever see someone break off the third prong on a three prong plug, I'm going to break off one of their fingers. Check the ground before playing! Free download of my cd!. Link to comment Share on other sites More sharing options...
PhilMan99 Posted July 2, 2003 Share Posted July 2, 2003 I carry one of those $5 circuit testers in my case, the kind with 3 LEDs to tell condition of each of hot/neutral/ground. Available at respectable hardware/electronics stores everywhere. Not an original idea, but a good one... Link to comment Share on other sites More sharing options...
fantasticsound Posted July 3, 2003 Share Posted July 3, 2003 Another handy electrical diagnosis tool to have is a small multi-meter. I have an old, $19.95 Radio Shack multi-meter I use to check for voltage between ground and the - side. This is fairly common, what with all the floating ground gear plugged in within a building. The voltage you see displayed on the meter can easily become nasty noise through your amp. It's easiest to find me on Facebook. Neil Bergman Soundclick fntstcsnd Link to comment Share on other sites More sharing options...
hags2k Posted July 3, 2003 Author Share Posted July 3, 2003 Thanks for the information, guys. I always knew that these issues were important, but I don't think I ever thought that one false step could KILL me or at least hurt me very badly. I went ahead and manually grounded my connections, and those of my bandmates' gear in my garage. I will be getting a nice grounding rod but until then I used an extension cord and a large pipe about 9 feet long buried in the ground. According to my cheap little tester, the connection is grounded. I think that ought to do the trick. unkownroadband.com - step into the unkown :-) Link to comment Share on other sites More sharing options...
... Posted July 4, 2003 Share Posted July 4, 2003 I hate you for only having this happen to you just now... The mighty grounding problem. It hurts like a somunumbeeyatch, don't it? I swear, half the time I sing at a club there is a ground problem when I initially test the mic. I'm sort of getting used to this huge jacob's ladder arcing between my lips. Link to comment Share on other sites More sharing options...
MattC Posted July 4, 2003 Share Posted July 4, 2003 That's a good reason to carry a foam windscreen in your bag. Actually, I'd carry 2 sizes: one to fit each of a SM57 and SM58. This way you can slip it on the mic and not be a part of the electrical ground connection. What makes mic shocks even worse is that your lips are wet, as opposed to your arms or fingers (unless you're quite sweaty). Wet skin, especially if you are very sweaty, substanially drops your skin's resistance, allowing it to carry more current. Current, not voltage, is what kills. ...think funky thoughts... Link to comment Share on other sites More sharing options...
hags2k Posted July 4, 2003 Author Share Posted July 4, 2003 Originally posted by Bumpcity: I hate you for only having this happen to you just now... The mighty grounding problem. It hurts like a somunumbeeyatch, don't it? I swear, half the time I sing at a club there is a ground problem when I initially test the mic. I'm sort of getting used to this huge jacob's ladder arcing between my lips.I suppose I got lucky on this one, depending on how you look at it... Anyway, it certainly does smart. That idea for a windscreen probably wouldn't hurt, either, in case of venues with questionable wiring. For some reason, this appears to be a substantial number, judging from others' testimony. If I spend too much more time pondering this, I'm liable to become paranoid. I suppose paranoid people rarely die from what they are paranoid about, though, so perhaps it's worth it! unkownroadband.com - step into the unkown :-) Link to comment Share on other sites More sharing options...
SaBer Posted July 4, 2003 Share Posted July 4, 2003 You can prevent getting lethal shocks from your bass by wireing a 1 nF/400V capacitor and a 220 kOhm ½ W resistor in parallel between the ground wire that goes to the bridge and the rest of your electronics. Also if you have whole metal knobs you might want to replace them with ones with plastic inside, or re-do their grounding also... Link to comment Share on other sites More sharing options...
Hanshananigan Posted July 8, 2003 Share Posted July 8, 2003 Originally posted by SaBer: You can prevent getting lethal shocks from your bass by wireing a 1 nF/400V capacitor and a 220 kOhm ½ W resistor in parallel between the ground wire that goes to the bridge and the rest of your electronics. Also if you have whole metal knobs you might want to replace them with ones with plastic inside, or re-do their grounding also...good advice, thanks! I also had a, well, shocking shock of the same sort. I wasn't sure if I should have gone to the hospital or beat the crap out of my bandmate who set the plug! Any ideas (other than sweaty bodies, or is that the answer?) why some have gotten killed and the rest of us get a scary jolt? Link to comment Share on other sites More sharing options...
Hanshananigan Posted July 8, 2003 Share Posted July 8, 2003 Originally posted by hags2k: Thanks for the information, guys. I always knew that these issues were important, but I don't think I ever thought that one false step could KILL me or at least hurt me very badly. I went ahead and manually grounded my connections, and those of my bandmates' gear in my garage. I will be getting a nice grounding rod but until then I used an extension cord and a large pipe about 9 feet long buried in the ground. According to my cheap little tester, the connection is grounded. I think that ought to do the trick.I'd have to ask confirmation from more talented folks in this forum, but one consideration when using the 9ft pipe is that if it's touching a root of a tree or something else that gets hit by lightning , your gear could become toast. Does that sound accurate? Link to comment Share on other sites More sharing options...
rumpelstiltskin. Posted July 8, 2003 Share Posted July 8, 2003 no, it isn't accurate, and more importantly, it's so unlikely that i wouldn't be concerned about it at all. robb. because i like people. Link to comment Share on other sites More sharing options...
Hanshananigan Posted July 8, 2003 Share Posted July 8, 2003 Originally posted by robb.: no, it isn't accurate, and more importantly, it's so unlikely that i wouldn't be concerned about it at all. robb.Thanks, robb, for the correction. Could you post a bit more info on why the rumor ain't true? Link to comment Share on other sites More sharing options...
Brendan Orr Posted July 8, 2003 Share Posted July 8, 2003 My guess to as why your gear wouldn't get fried is because the lightening already reached the ground which carries the opposite charge of the sky, the charge differences (I think) negate at the ground and all is well...I think. groove, v. Inflected Form(s): grooved; groov·ing transitive senses:1a.to make a groove in;1b.to join by a groove;2.to perfect by repeated practice;3.to throw (a pitch) in the groove intransitive senses:1.to become joined or fitted by a groove;2.to form a groove;3.to enjoy oneself intensely;4.to interact harmoniously - groov·er noun Link to comment Share on other sites More sharing options...
Tom Capasso Posted July 8, 2003 Share Posted July 8, 2003 I hope the answer is that you wouldn't be so unintelligent as to be plugged in anywhere near a tree in a thunderstorm.... Tom www.stoneflyrocks.com Acoustic Color Be practical as well as generous in your ideals. Keep your eyes on the stars and keep your feet on the ground. - Theodore Roosevelt Link to comment Share on other sites More sharing options...
hags2k Posted July 9, 2003 Author Share Posted July 9, 2003 Well, electricity travels through the path of least resistance and highest potential. The potential between the sky and ground would be greater than between the sky and the amp. Also, I've been told that electricity tends to jump UPWARD from the ground to the sky and not downward, and the grounding point shouldn't have the correct charge to INDUCE a bolt, and should be fairly impervious. The whole idea of grounding, in fact, came as a way of diverting lightening from towers to protect from fires many moons ago, and they are quite effective at diverting lightening from other potential targets. unkownroadband.com - step into the unkown :-) Link to comment Share on other sites More sharing options...
Hanshananigan Posted July 16, 2003 Share Posted July 16, 2003 fig posted this a couple of months ago on a thread called "Hotspots to check for a bad ground on my bass?" http://www.guitarnuts.com/safety/clubshock.html It's an excellent explanation about grounding problems that could be fatal. Link to comment Share on other sites More sharing options...
... Posted July 16, 2003 Share Posted July 16, 2003 Originally posted by hags2k: Well, electricity travels through the path of least resistance and highest potential. The potential between the sky and ground would be greater than between the sky and the amp. Also, I've been told that electricity tends to jump UPWARD from the ground to the sky and not downward, and the grounding point shouldn't have the correct charge to INDUCE a bolt, and should be fairly impervious. The whole idea of grounding, in fact, came as a way of diverting lightening from towers to protect from fires many moons ago, and they are quite effective at diverting lightening from other potential targets.Argh!! Please! Don't make me remember to horrors of second quarter physics. That one kicked my ass after I got a 4.0 in mechanics. Me and electromagnetic fields don't get along too well. I swear, I'm much more able to talk about plasma states than field charges between two points. Quantum position discussions anyone? Bueller? Bueller? Link to comment Share on other sites More sharing options...
hags2k Posted July 16, 2003 Author Share Posted July 16, 2003 Originally posted by Bumpcity: Argh!! Please! Don't make me remember to horrors of second quarter physics. That one kicked my ass after I got a 4.0 in mechanics. Me and electromagnetic fields don't get along too well. I swear, I'm much more able to talk about plasma states than field charges between two points. Quantum position discussions anyone? Bueller? Bueller?[/QB]HA! Thanks for the words fear. I'm taking EM this fall, along with my third semester of Calc and my first semester of diff-eq. I think I'll be getting MY ass kicked, as well. Come to think of it, I think there's another physics class in there, too. I suppose I deserve it, though, for being silly and picking physics as a major. God help me! BTW, can I ask you for help on my homework? unkownroadband.com - step into the unkown :-) Link to comment Share on other sites More sharing options...
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