Trouble Posted July 31, 2011 Posted July 31, 2011 I played my little VibroChamp at a gig last night. I plugged it into a power strip that the PA was plugged into, the power strip was plugged into an extension chord. Every thing that was electric that I touched while touching my guitar strings shocked the shit out of me. The PA, mics, cable ends the only thing that didn;t shock me was the metal pop screen on the mic(thank god) although the body of the mic would light me up. My champ has a 3 prong power cable, and I've never had this happen before last night any ideas what was going on?
Trouble Posted July 31, 2011 Author Posted July 31, 2011 By the way, guitar+ tuner+ small tube amp= sweetest natural overdrive and sustain ever!
GuitArtMan Posted July 31, 2011 Posted July 31, 2011 Does your amp have a ground switch? If so, you need to flip it the other direction. Or if the PA amp has a ground switch, flip it. If your amps(s) don't have a ground switch one of them is wired wrong. I'm not really up on power electronics and/or electrical, remember with your basic 3 prong wiring theres not, neutral and ground. One of your pieces of equipment has something switched (I think it's normally the hot/neutral but I'm not positive). The ground switch on amps was used to correct for this, and is a carry over from the days of two pronged wiring. Maybe and electrician or someone who is up on power electronics will jump in here.
111518 Posted July 31, 2011 Posted July 31, 2011 Polarity had to be reversed somewhere ...was there a ground lift on the PA, or on the extension chord? Or, perhaps the rec. that you started from might have been wired backwards. Usually, as you obviously know since you mentioned the power strip, having everything on one circuit (power strip) is a good way to prevent this, (the leader of the band I play in is an electrical engineer, and he insists everything comes out of one outlet, and he carries a rec. tester to make sure that rec. is wired correctly) but, if anything in the system gets plugged in such that the neutral/ground side is picking up power and that power is not going to ground, then that power is going to want to go though you from your grounded guitar strings to the ground offered by the grounded metal case of other equipment. The advantage of polarized or three pronged plugs is that they should keep everything consistent, but it only takes one device on the circuit that is not properly polarized to create a problem. Be careful! Just read GuitarArtMan's post ... same logic --switching the polarity on your guitar amp should line it up with the device causing the problem.
Genericmusic Posted July 31, 2011 Posted July 31, 2011 Does your amp have a ground switch? If so, you need to flip it the other direction. Or if the PA amp has a ground switch, flip it. If your amps(s) don't have a ground switch one of them is wired wrong. I'm not really up on power electronics and/or electrical, remember with your basic 3 prong wiring theres not, neutral and ground. One of your pieces of equipment has something switched (I think it's normally the hot/neutral but I'm not positive). The ground switch on amps was used to correct for this, and is a carry over from the days of two pronged wiring. Maybe and electrician or someone who is up on power electronics will jump in here. Polarity had to be reversed somewhere ...was there a ground lift on the PA, or on the extension chord? Or, perhaps the rec. that you started from might have been wired backwards. Usually, as you obviously know since you mentioned the power strip, having everything on one circuit (power strip) is a good way to prevent this, (the leader of the band I play in is an electrical engineer, and he insists everything comes out of one outlet, and he carries a rec. tester to make sure that rec. is wired correctly) but, if anything in the system gets plugged in such that the neutral/ground side is picking up power and that power is not going to ground, then that power is going to want to go though you from your grounded guitar strings to the ground offered by the grounded metal case of other equipment. The advantage of polarized or three pronged plugs is that they should keep everything consistent, but it only takes one device on the circuit that is not properly polarized to create a problem. Be careful! Just read GuitarArtMan's post ... same logic --switching the polarity on your guitar amp should line it up with the device causing the problem. +1 for both the above answers. You were out-of-phase somewhere along the line. Flipping a polarity switch would correct the problem. This was a big problem in the '60's and actually killed a few musicians. The lead guitarist for Stone the Crows come to mind.
Trouble Posted July 31, 2011 Author Posted July 31, 2011 I was thinking the same thing, the little champ doesn't have a ground switch, not sure about the PA but I couldn't find one on it. I wouldn't be surprised if the receptacle was wired backwards since the house was all good ol' boy work. I bet I checked the pop filter on the mic with my hand 10 times before I would sing into it! it must be insulated from the rest of the mic. I really didn't get to check everything over I just showed up and plugged in pretty much. Thanks guys.
TalismanRich Posted August 1, 2011 Posted August 1, 2011 I remember that happening to me in the 70's. Our old Kustom 100 PA had a switch that went to either side, reversing polarity. Center was off. My Guild Thunderbird had a polarity switch as well as a hum pot on the back. We had to make sure we didn't flip the PA once everyone was synced up. I've had a few "sparks off the lip" moments back in the day! A lot of old amps have a "death cap". It's a capacitor that goes off the power leads. If the capacitor fails it can feed 120v through to the chassis. Not a good thing to happen.
Trouble Posted August 1, 2011 Author Posted August 1, 2011 I can't imagine what 120v to the lips would feel like but I'm pretty sure that I would never sing into a mic again.
Guest HRB853370 Posted August 1, 2011 Posted August 1, 2011 My 1963 Ampeg G15 would light the crap out of me if my polarity switch wasn't flipped the right away. Of course, you would know if it wasn't because the hum you would get through the speaker. I remember standing barefoot on my parents basement concrete floor and it was electrifying!
bobmeyrick Posted August 1, 2011 Posted August 1, 2011 +1 for both the above answers. You were out-of-phase somewhere along the line. Flipping a polarity switch would correct the problem. This was a big problem in the '60's and actually killed a few musicians. The lead guitarist for Stone the Crows come to mind. Ah, Stone the Crows! One of my favourites from when I was a lad. Les Harvey was a great guitarist and younger brother of Alex Harvey (of Sensational Alex Harvey Band fame), and Maggie Bell was one hell of a singer, sort of a Scottish Janis Joplin. Well worth checking out if you're a fan of late '60s/early '70s British Blues Rock.
DetroitBlues Posted August 1, 2011 Posted August 1, 2011 I'm very lucky with the KBP810 amp, it has a switch on the back to reverse the polarity. Never thought much of it until I read this thread!
kbp810 Posted August 1, 2011 Posted August 1, 2011 I'm very lucky with the KBP810 amp, it has a switch on the back to reverse the polarity. Never thought much of it until I read this thread! Nah, it's just there for looks now Three prong plugs have made them obsolete
H Posted August 1, 2011 Posted August 1, 2011 Nah, it's just there for looks now Three prong plugs have made them obsolete The Limey has a Ground switch too. I felt a bit stupid after asking Tube Amp Doctor, the kit supplier, which way the switch should go and being told "It doesn't do anything, sir"
DetroitBlues Posted August 1, 2011 Posted August 1, 2011 Nah, it's just there for looks now Three prong plugs have made them obsolete If that's the case, it should be a high gain toggle switch!!!! YEA!!!!!
Genericmusic Posted August 2, 2011 Posted August 2, 2011 I can't imagine what 120v to the lips would feel like but I'm pretty sure that I would never sing into a mic again. Try taking one on a tooth. It's like electroshock therapy. I'm still twitching and that was 40 years ago.
DetroitBlues Posted August 2, 2011 Posted August 2, 2011 Try taking one on a tooth. It's like electroshock therapy. I'm still twitching and that was 40 years ago. Did it rework your fillings?
Trouble Posted August 3, 2011 Author Posted August 3, 2011 I have worked around electricity enough to know I don't like getting shocked, and the other night I could tell I wasn't going to die from the jolt I was getting it was just very uncomfortable. I still don't know exactly what was going on, I was plugged in with a 3 prong plug to a power strip that the PA was plugged into(with a 3 prong plug). The stuff plugged into the PA is what was shocking me, and I should have had the same Polarity. I'm starting to think that someone must have unplugged me or the PA after I set up and plugged into a different outlet. In any case, hoping it doesn't happen again, getting shocked sucks.
Genericmusic Posted August 3, 2011 Posted August 3, 2011 Ah, Stone the Crows! One of my favourites from when I was a lad. Les Harvey was a great guitarist and younger brother of Alex Harvey (of Sensational Alex Harvey Band fame), and Maggie Bell was one hell of a singer, sort of a Scottish Janis Joplin. Well worth checking out if you're a fan of late '60s/early '70s British Blues Rock.
DetroitBlues Posted August 4, 2011 Posted August 4, 2011 I have worked around electricity enough to know I don't like getting shocked, and the other night I could tell I wasn't going to die from the jolt I was getting it was just very uncomfortable. I still don't know exactly what was going on, I was plugged in with a 3 prong plug to a power strip that the PA was plugged into(with a 3 prong plug). The stuff plugged into the PA is what was shocking me, and I should have had the same Polarity. I'm starting to think that someone must have unplugged me or the PA after I set up and plugged into a different outlet. In any case, hoping it doesn't happen again, getting shocked sucks. Now I know why a lot of people recommend power conditioners for their amps.
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