electric shock through mic.. then guitar,grounding or caps?

[Kapo_Polenton]

So I'm rockin out on my 74 YBA-1 that i just plexified and I decide to crack the mics out and catch a clip for you fine folks on rig-talk. I touch the mic and feel that numb tingling sensation against my fingers.. that's weird.. touch it again, and little zap, that's definitely there. Power down that amp, unplug the amp, plug in my lynchbox and I swear, I'm feeling some current on my pinky finger ( I cradle the bottom of the bridge pickup sometimes when i play). What would be the deal there? Was the initial shock what i was feeling on the second amp or was my guitar starting to use me to ground part of the signal? Did the guitar take on a charge of some type? I'm thinking one of two things.. maybe the ground lift on the Traynor (though it appears to not be engaged.. ) or maybe those old 74 filter caps are dying and not able to handle the load I am putting on them now that i am using the hotplate and driving the amp hard?

The good news, amp sounds pretty good ! bad news.. zap zap is no fun nor is my numb pinky picking hand finger..

 

[snakeman1986]

i had something like that happen to me as well. i'm the background singer/guitar in the band and i tend to sing close to the mic to the point where my lips touch the mic. the other night at practice i shocked myself when i touched my lips to the mic. hurt pretty freakin bad.

 

[skoora]

There's a ground differential somewhere. Where the mic is plugged in is probably receiving power from a different circuit than where the amp is plugged in. It could be outlets in the same room but they still may be on different circuits. If this is happening at home you may want to call an electrician. More likely to happen at a bar/club where the P.A. is on a different circuit than the stage gear.

If your getting a shock from the guitar when not near the mic a ground could be lifted or disconnected somewhere in the circuit that the amp is plugged into. Or you might want to check that the 117VAC is on the correct plug in the wall socket.

 

[sixstringking713]

DO NOT lift the ground on the amp, EVER. try to plug the amp into the same outlet or circuit as the power amps for the PA first (usually fixes the issue). If doesnt, try plugging into same circuit/outlet as mixer and lastly try lifting ground on mixer

 

[Motorpud]

A buddy of mine fired up a big Ampeg bass rig at GC a few years ago and got the shit shocked out of him right in front of one of the sales guys, the look on his face was priceless

The manager came out and actually offered him like $500 off the rig (same model but a non-broken one) and he bought it

 

[Kapo_Polenton]

There's a ground differential somewhere. Where the mic is plugged in is probably receiving power from a different circuit than where the amp is plugged in. It could be outlets in the same room but they still may be on different circuits. If this is happening at home you may want to call an electrician. More likely to happen at a bar/club where the P.A. is on a different circuit than the stage gear.

I suspect this because the outlet I run my PC on is on a different breaker than the amps. I remember this while doing my basement reno because i had diff outlets working at diff times depending on what I was doing.. I didn't wire it this way, it was done this way by the previous owner. The two outlets i run amps and pedals or rack gear from are on the same circuit. Perhaps I should move the power source for the mic pre and computer interface over to the outlet with the other gear. That would solve it would it not? As for rewiring.. not sure I want to spend the 1000$ on getting an electrician in right now as I am house broke after all the latest renos and other costs I had to incur. That does make sense though. I suspect that it numbed my finger for the next 20 min and that is why I thought I was feeling it after i had turned off the gear running off the offending circuit. Funny, because I've run amps off of it before without issue.. good to know though.

 

[Schaf]

More that likely a polarity issue on the outlet. Get one of those cheap testers and check it out. I know that sounds too simple, but when you get bit by the mike 90% of the time it's polarity.

 

[blackba]

More that likely a polarity issue on the outlet. Get one of those cheap testers and check it out. I know that sounds too simple, but when you get bit by the mike 90% of the time it's polarity.

+1, that or its a grounding issue.

I have gotten shocked on my lips twice, it hurts.

The first time was when I was playing bass, my ampeg bass amp was grounded, I was touching the strings. I stepped up to the mic and zap. The PA system was run off an extension cord and the extension cord had the ground pin removed. I was so angry with my friend who did that. Once the PA was grounded, we had no issue.

The 2nd time was when we had 2 mixing boards and an 8 channel main and a 6 channel submix. The 8channel mixer was grounded, the 6 channel only had a 2 prong cord and was not grounded. We run a couple of condensor mics on the 6 channel with phantom power and again when I stepped up to the vocal mic connected to the main mixer, zap. We switched to cardiod mics on the 6 channel and turned off the phantom power and didn't have the issue again.

 

[Kapo_Polenton]

Good idea, I'll pick one up at home depot and get sucked into buying something else that is "on sale" while I'm there.... isn't that always the way though.

 

[Burn]

I moved my amps last year and it turns out that for some reason the ground wasn't connected at the new outlet I plugged them into.

I got shocked pretty badly a couple of times before I got that fixed, and even now when I play I'll sometimes start hallucinating that I'm getting that "tingling in the fingers" thing. I think it's psychological. Your mind's developing an aversion to something that can hurt you...

 

[midnightlaundry]

IN the 80's, I took a jolt to the lips from a microphone. Fuck that shit...

 

[JamesPeters]

Is the amplifier properly grounded? Was a 3-prong plug installed properly (and the old "death cap" removed)? If not, do those things.

Oh, and electrolytic filter caps which are over 30 years old should definitely be replaced too.

 

[Kapo_Polenton]

Yes, the 3 prong power cord was installed... what is this death cap you speak of? Going to be putting an order in for new filter caps shortly, was just messing around with the amp to gauge the tone after a few simple mods..

 

[blackba]

Yes, the 3 prong power cord was installed... what is this death cap you speak of? Going to be putting an order in for new filter caps shortly, was just messing around with the amp to gauge the tone after a few simple mods..

Check out this link, particularly the pictures, they show the death cap and what the circuit looks like when its removed.

http://www.theguitarfiles.com/guitarfile644.html

 

[Kapo_Polenton]

Thanks for the suggestions and links folks.. most helpful