Shocking

[grinder]

While recording talk box, I get a little zap when my lips get too close to the mic.I assume it is a ground problem, but as far as I know my guitar set up is well grounded.I don't get any hum or noises from it and my cords are in good shape.My guitar amp and recording equiptment are on the same circut, but differant outlets.How do I find the problem and remedy it?
Thanks, Grinder

 

[Clive Hugh]

I hope you have some kind of protection device between your wall and gear, it could be serious.
I lived in a house once that had a bad wiring problem and if my inside arm touched the guitar strings I got a buzz, I got an electrician in and he found it was an earth problem, this was 240 volts, but i guess the same applies in 115 too, although you might have slightly different regulations.
Also some people are more susceptable to small power leakages.

 

[64Firebird]

If your amp has a working ground switch, switch it. Some of the fender reissue amps have a ground switch, but they aren't even hooked up and don't do anything. You could also just unplug from the wall, flip the plug over and plug it back in.

 

[Dakota]

Or the problem could be the mic. Does the mic have 48 volts phantom power? The 48 VDC could be shorted to the mic case...

 

[grinder]

The house wiring is fairly new, not to say there isn't a wiring problem, but I doubt it.My amp doesn't have a polarity switch and has a three prong plug.Should I try using a two prong adapter and flip the plug over. The mic I'm using is a dynamic, Shure 58.Did I post this in the right forum?Seemed as good as any to me. Thanks, Grinder

 

[Dakota]

No!!! Don't try the 3 prong to 2 prong adapter!

The ground plug is a safety device. If you use the adapter, your amp will no longer be grounded, and if any wires short out and put, say, 110 Volts into your guitar, you could be killed!

 

[Dakota]

The way grounding is designed, both your guitar, thru your amp and the mic, thru the mixer or PA should be grounded to 0 Volts. Somewhere, you lost a ground.

If you have a volt meter, measure between a known ground, say a copper water pipe, and the guitar strings. Anything more than about 5 volts AC, and you'll know the guitar has lost a ground. Do the same with the mic.

Also check the mic for 48 volts DC, phantom power.

Don't take chances if you're not sure. Find someone who has some electrical experience.

 

[Major Tom]

Watch out for the same circuit but different outlet thing - its not uncommon for a do-it-yourselfer to replace an outlet and connect the wires backwards - stuff will still work when plugged in, but a shock potential in conjunction with another outlet.

 

[Jblount]

Uhhhmmm, check the receptacle. It may have a ground hole, but no ground wire connected to it, yes I have seen this, especially in remodle jobs. If you have a meter, check between ground and the hot, it should be 110 volts. You are missing a ground somewhere, maybe in the amp, a piece of pa, something.

 

[Paj]

Grinder:

(1) You can probably check out that same-circuit-different-outlet thing by plugging a power strip into one of the outlets and plugging everything that was in the second outlet into the power strip. Then, everything will be in one outlet.

(2) If you're getting a shock, DON'T USE A 3->2-PRONG ADAPTOR.

(3) You may have a worn/defective grounding socket on the outlet. Contractors, oddly enough, use "contractor grade" materials made for "standard duty", especially for items that are not obvious or easily accessible.

(4) Portable GFID are available for less than $35 US, and wall-installs are less than that. I don't think the grounding problem is as common as in the past (I remember Stone The Crows) but having a portable GFID for gigs makes sense.

(5) REALLY IMPORTANT QUESTIONS: Exactly what kind of talk box do you use? Did you have to wire into your amp/speaker for your talk box? Do you use a tube amp with your talk box? Do you get shocked when the talk box is completely removed/disconnected from your effects chain? Talk-boxes are such a cool tool but there are reasons why they are not ubiquitous . . .


Paj
8^?

 

[ZoSo58LP]

I hope you have some kind of protection device between your wall and gear, it could be serious.
I lived in a house once that had a bad wiring problem and if my inside arm touched the guitar strings I got a buzz, I got an electrician in and he found it was an earth problem, this was 240 volts, but i guess the same applies in 115 too, although you might have slightly different regulations.
Also some people are more susceptable to small power leakages.

no freakin way! i used to constnatly get shocked by my strat on my inner arm when they touched the strings too! same wiht my p-bass...wow thats weird, but it hasn't done it in years and we didn't change anyhting.....whoa, weird eh

 

[grinder]

Thanks for the replies.I'll check the recepticle for ground problems.I'm using a Carvin tube head and an unmodified Heil talk box connected directly to the speaker output without any extension cab.I haven't been shocked using just the mic, but don't usually sing too close to the mic.

 

[Paj]

Heil---I was afraid you'd say that! The standard, but watch out!

Try completely disconnecting/removing the Heil from your setup before you call in the electrician. Do you still get shocked?

By the way, I hope that you're not using a standard guitar cable between your amp and the talkbox or your talkbox and the speaker. Are you?


Paj
8^?

 

[grinder]

No, I'm not using a guitar cable, it's a speaker cable.Are there specific problems with Heil talk boxes and do you think that could be causing the shock?The only part the talk box I'm touching is the tube, which is non conductive.I will try the mic/guitar with out the talk box and see if there is still a problem.I'm going to check the outlet grounds tomorrow.Thanks, Grinder