Grounding a lap steel

Steve Waltz · From: USA

I need to open my home made lap steel up to add a ground wire to the output jack. It's a single coil pickup. If I use a star ground system is there any downside to attaching an additional ground to the key head? I understand that the strings will ground to the bridge and key head anyway but is there any possibility that noise might choose the path of the key head ground rather than through the stings and over and maybe into the pickup?

I channel my neck so there is already an easy route from key head to output jack.

Thanks,
Steve

Paul Arntson · From: Washington, USA

I would say just try it and see. You can always pull it off again. There is a theoretical chance that the loop would add hum, but there might be a benefit in trying it. If nothing else, we'll learn something. Please let us know the results.
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Excel D10 8&4, Supro 8, Regal resonator, Peavey Powerslide, homemade lap 12(a work in progress)

Georg Sørtun · From: Mandal, Agder, Norway

You risk creating a ground-loop, which I advice against as it may actually increase noise-sensitivity.

Paul Arntson · From: Washington, USA

I agree in theory, George, but a ground loop's sensitivity in this case corresponds to the surface area enclosed by the loop, which is pretty small here. If it were me, I'd just try it to see what if any effect it has. There might be some other effect going on like reduced cnnection resistance which could be beneficial. Electrically, it wouldn't be much different from one of the strings, which are already loops, just steel instead of copper.
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Excel D10 8&4, Supro 8, Regal resonator, Peavey Powerslide, homemade lap 12(a work in progress)

Georg Sørtun · From: Mandal, Agder, Norway

Sure Paul, no energy involved so doesn't hurt testing. If the keyhead/nut is all metal the extra ground should have zero effect either way.

Paul Arntson · From: Washington, USA

Yes exactly. Different story if it were a power circuit.
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Excel D10 8&4, Supro 8, Regal resonator, Peavey Powerslide, homemade lap 12(a work in progress)

Jack Hanson · From: San Luis Valley, USA

I run a ground on all my rescue guitars from the jack to the underside of the bridge. Without exception, they're all quiet as a church mouse.

Steve Waltz · From: USA

Thanks for the input. I thought the star grounding system would avoid a ground loop. I think I'll give it a try and see how it goes.

Thanks

Georg Sørtun · From: Mandal, Agder, Norway

Steve Waltz · From: USA

Got it. Thanks,
Steve

Jim Sliff · From: Lawndale California, USA

If you are already grounded through the bridge adding a tuning peg ground "sort of" creates a ground loop, but only in name. The "path" to the guitar's ground connection is unchanged and there are no active circuits involved.

But what it does add is a very large antenna to pick up all sorts of interference.

It can help to add shielding in the control and/or pickup cavity as long as it's all connected to ground, but additional grounding at the tuning keys is counter-productive.
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No chops, but great tone
1930's/40's Rickenbacher/Rickenbacker 6&8 string lap steels
1921 Weissenborn Style 2; Hilo&Schireson hollownecks
Appalachian, Regal & Dobro squarenecks
1959 Fender 400 9+2 B6;1960's Fender 800 3+3+2; 1948 Fender Dual-8 Professional

Donny Hinson · From: Glen Burnie, Md. U.S.A.

Doesn't grounding the bridge automatically ground the tuning keys?

Georg Sørtun · From: Mandal, Agder, Norway

Steve Waltz · From: USA

I get how the normal grounding is done and I'll do that. My question was more about being curious of other options. Kind of like this question:
"But what it does add is a very large antenna to pick up all sorts of interference."

Since the keyhead is grounded by all of the strings now, how would adding one additional wire inside the neck now cause a very large antenna? Aren't the strings an antenna now?

I assume it because of grounding at both ends which now makes the strings an antenna where they weren't when they were only grounded at one end?

Just curious, not debating.

Thanks,
Steve

Georg Sørtun · From: Mandal, Agder, Norway

Grounding at both ends create a loop = a coil. Connect that with the PU coil = an RCL element with lots of unknown, a shielded cable = an RC element, and then to an amp-stage with lots of intended and unintended LF and HF characteristics…
… and you may may end up with anything from an instrument that picks up excessive amounts of low frequency hum and noise, to one that picks up radio-stations, or you may not notice anything special or wrong because the "gamble" of connecting various elements together doesn't cause any stray and troublesome effects in your particular set-up.

Your initial star-grounding is good practice, that in most cases works best when it comes to reducing noise pick up. Adding a ground-loop to it CAN lead to worse results.
In my 55 years of working and playing with audio and HF equipment, I have seen, heard, and fixed, all sorts of unwanted effects of created loops and other grounding and wiring practices. As I cannot put all that troubleshooting experience down in writing that would be of use to all that many others, I advice all who ask about these issues to keep it as simple as possible.

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