Grounding the bridge

[Tom Wolverton]

I've noticed with several lap steels I own, that running a ground wire to the metal bridge/tailpiece assembly helps reduce signal noise. Yet I find a lot of lap steels with no ground wire to the bridge. Why not? This seems like a "no-brainer" to me. Why would anyone not do this? Does it change tone or is it a safety issue?

[Fred]

If everything is grounded properly (guitar amp, pa equipment, anything else you might touch) there isn't any danger.

If things aren't grounded properly then you can get a shock when you touch both the guitar strings and a mic for example.

I've gotten zapped when I've touched a second amp. I have a lot of old amps. Modern equipment with three prong plugs shouldn't be a problem... if the wall sockets are wired properly.

[David Haddock]

I have guitars with humbuckers that are shielded with foil in the cavities and no ground to the bridge and they are very quiet (shielding is grounded). Single coil pickup guitars on the other hand may require a grounded bridge if played under certain stage lights no matter how well they are shielded...

[Bill Creller]

I agree with David. Shielding the wiring can isolate the bridge and strings from the cord ground in case of plugging amps into bad/mis-wired outlets.

[Tom Wolverton]

First let me say this: I hold no one liable for any advice given here. I do this at my own risk. I hold no poster or this forum liable for any electrical advice given to me.

Now, what exactly are you guys saying? Go ahead and run the ground wire to the bridge? It is a single coil pickup. There is usually less hum when I do this and I know (and have experienced) the ground jolt from time to time. I'm ok with that.

[Fred]

Now, what exactly are you guys saying? Go ahead and run the ground wire to the bridge?

Yes.

[Denny Turner]

If a guitar is noisy without strings grounded, ...and electronics cavities shielding won't solve the problem, then the strings should be grounded. Grounding the strings shouldn't be a danger if the Player and/or Band is wise:

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NO-ONE should be plugging an amp into wall sockets without having and using 2 safety devices:

(1) A small device about the size of an extension cord's male plug, available for under $10 at Radio Shack, that plugs into a wall socket and displays one of 3 patterns on 3 lights on the device, which will tell you if the wall socket is wired correctly. These little devices will also tell you what needs to be done to a bad house fuse / breaker box or wall wiring so the owner can get it fixed before it kills someone. You might even be successful in pointing out his extreme liability and thus talk him into installing ground fault circuit breakers in his fuse / breaker box, during which bad wiring must be corrected for the GF breakers to stay on / not trip.

(2) A dual socket outdoor-grade ground fault power strip good for 1875 watts (standard wall socket limit) should be part of every Player's assessories. 2 outlet strips are rather standard for ground fault strips; And more than 2 outlets risks "Murphy" overloading the strip. NOTHING in a band should be plugged into wall sockets without these devices, especially gig outlets, ....IMHO (after being shocked by band equipment pretty darn good several times over the last 50 years). If a band is so inclined to ignore such easy / simple / no-brainer safety, then a Player can use a ground fault strip for his / her equipment, which will trip / turn-off your equipment faster than you can even feel any electricity should a ground fault occur through your body parts. A ground fault power strip will also alert everyone involved that a ground fault exists. GROUND FAULTS ARE DEADLY under the right conditions.

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I acquired and religiously used the above devices after playing a biker party about 20 years ago. Band was set up on a large concrete patio, soaked and standing in beer, and hooked up by long extension cords (long / high resistance for the AC power). A biker walked up while I was playing, to pour a beer down my throat. Yea, this will look cool. The beer entering my mouth completed the ground fault between my playing hands and the wet ground he was standing on bare-footed. Even if the AC power had been wired correctly (it wasn't), the biker still provided a lot less resistance to the ground he was standing on than the long extension cords. The beer was fully loaded with 110 Volts. It was only my muscles going into lock-up convulsion that pulled me away from the beer and saved my life ....as the biker unsuccesfully chased my mouth until the beer can was empty.

[Rocky Hill]

Run the ground! You have absolutely NOTHING to lose by doing it.

Rocky

[David Haddock]

I didn't get into further, but there is a trick described in Dan Erlewine's book on guitar repair involving a resistor and capacitor soldered in parallel in between the bridge and ground. It is a little safety device that burns out if too much current goes through, saving your life or saving you from a shock... I can look it up if interested.

[Bill Creller]

The resistor and cap method sounds OK. It will be an effective grounding scheme without having a hard wire there, depending on the value of the resistor.

[Tom Wolverton]

Thanks to all of you for these answers. I'll rig up the ground wire to the bridge and get a GFI outlet box. That's a good idea, all around.

Now I can't leave my room, no TV, no video games...."Son! You're grounded!" : )

[Lynn Oliver]

...(1) A small device about the size of an extension cord's male plug, available for under $10 at Radio Shack, that plugs into a wall socket and displays one of 3 patterns on 3 lights on the device, which will tell you if the wall socket is wired correctly...

I just bought one of these at Home Depot for $3.97.

[David Haddock]

...(1) A small device about the size of an extension cord's male plug, available for under $10 at Radio Shack, that plugs into a wall socket and displays one of 3 patterns on 3 lights on the device, which will tell you if the wall socket is wired correctly...

I just bought one of these at Home Depot for $3.97.

I just got home to look up the safety measure and Erlewine's book also talks about the outlet tester...

To quote the resistor/cap method, "wire in parallel a 220k ohm resistor (colored bands are red, red and yellow, and silver or gold) and a .001 capacitor with a minimum voltage rating of 500 volts. Twist the wires together and solder them. This can be done out of sight in the cavity and it only lets 40 volts through to your strings if a shock is headed your way."

Warning, if you have metal knobs you can still get shocked, keep that in mind so if you want a completely safe system you'll have to insulate your pot shafts from the knobs and any switchs etc...

nuff said about this i guess.

[Tom Pettingill]

...
NO-ONE should be plugging an amp into wall sockets without having and using 2 safety devices:...

Good call Denny, its cheep and easy to play it safe. Bad / incorrect wiring is more common than most might think.
Here is a pic of one of the testers, I keep one at home and one for use out on the job.


Ground fault protector power strips are cheep insurance and even installing a GFI wall socket is worthwhile in higher risk areas.



Back to the subject of grounding the bridge / strings, I always do.

[Bill Creller]

The GFI receptacles are ideal in many situations. I even put some in my boat.
Problem is, if playing in a venue like a club or bar, the wiring scheme in an old building may be ready to zap the musicians. The tester mentioned above is used by many bands when they set up at a strange location.
Question is, what's the fix if the wiring isn't right? An isolation transformer set-up to carry along at gigs is what fome folks use.

[Rich Hlaves]

My vote is ground the bridge. I do on everything I build or service. Today, Fender still grounds vibrato spring claws and ultimately the stings on Strats. These are UL and CE certified appliances. The high end of their line uses "noiseless pickups", yeah right, and the guitars still have the bridge ground circuit.

All the advice about testing the house power before plugging in is right on. I played a private party 15 years ago or so and plugged in my Peavey CX800X power amp for the PA mains and flipped it on. Instant huge hum from the amps transformer, the whole rack vibrated. Turns out the homeowner wired that outlet on his patio himself using both hots and a common at the breaker box! 240 VAC at the receptical. No damage to the amp fortunately. I got it shut down quickly enough.

I will say however, I have never changed the cord on my favorite amp, a '67 Pro Reverb. Still has a two prong plug. I am very carefull when I set this amp up. There are rules I don't break: No bare feet. Use a circuit tester. Plug in a power conditioner with a volt meter first!

Be careful out there,

RH

[David Haddock]

if you don't have a circuit tester or just to make it a part of your setup routine when on stage, touch the microphone to the strings of a grounded-bridge guitar and see if you get an arc, don't touch the strings or metal parts when you do this...

[Alan Brookes]

Run the ground! You have absolutely NOTHING to lose by doing it.

This is exactly what I was going to say. You can get away without grounding, depending on the electrical circuit in the location where you're working and all the other equipment plugged in and in the proximity, but it's a hit-and-miss affair. Ground everything you can.