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ground/shielding issues with a Les Paul


doc taz

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Hmph. It's been a while since my dad played his alpine white 1994 Gibson Les Paul Studio. Oddly enough... the thing buzzes when his hands are off the guitar. :( I knew that it was some kind of shielding issue... at least I think that's what it is. We haven't taken anything apart yet, and he may take it to a trusted repairman today or tomorrow. None of his other electrics seem to exhibit this background buzzing.

 

My Ibanez electric guitars (2 RG's) seem to have this problem, but it isn't as pronounced, so I can live with it. I'd still like to fix these up, though, at some point.

 

We've tried everything, from changing amps, staying away from tv's and monitors, to even going direct to my Zoom gfx-5 in bypass mode, using 4 AA batteries. The buzzing noise is still there when the hands are off the strings. It's enough of a problem that if I recorded it onto my cassette 4 track, even with its noise reduction... *buzz*.

 

I just wanted to see what any of you may have to say about it before the LP's taken in for repair.

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every passive electric guitar uses an attachment from the electroniucs cavity to the bridge or string tailpiece tot he strings to incorporate the human into the grounding scheme. There is likely nothing wrong with the guitar.

 

Bill

"I believe that entertainment can aspire to be art, and can become art, but if you set out to make art you're an idiot."

 

Steve Martin

 

Show business: we're all here because we're not all there.

 

 

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Originally posted by Bill@Welcome Home Studios:

every passive electric guitar uses an attachment from the electroniucs cavity to the bridge or string tailpiece tot he strings to incorporate the human into the grounding scheme. There is likely nothing wrong with the guitar.

 

Bill

Okay... but would extra shielding help reduce some of the buzzing, anyhow?

 

Here's an example from sevenstring.org: http://www.sevenstring.org/forum/showthread.php?t=15955&page=3

 

Look at the third response on that page, you can't miss it.

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Originally posted by Dr. Taz:

Okay... but would extra shielding help reduce some of the buzzing, anyhow?

 

The early Fenders came with complete copper shielding pans in each cavity and on the back of the pickguard. We've also done things like paint the cavities with conductive paint (did this backstage one day on Prince's guitar.... no help.) This is not going to solve your problem, as far as I can see.

 

The buzz that you describe goes away when the guitar is being played, because the player completes the ground. A lot of guys are nervous about this, but in the real world I have been confronted with two occasions of a grounding problem causing injury, and one had to do with a difference in potential between the guitar ground and a PA ground (which cased the death of the guitarist from Stone the Crows some 25 years ago or so) and the other was due to a miswired amplifer which put high voltage down the ground of the guitar, frying the player and knocking him out for a few minutes. Neither of these scenarios is nice but both could have been prevented had the guitarist or his tech used a wiggy or meter at soundscheck. But out of the thousands and thousands of guitarists and gigs of which I have been a part or have read about, these are the only two that I know about that have had any serious repercussions, over all these years since I started playing music back in the 1960s. Yes, we occsionally get a jolt when we are not careful, and need to reverse the amp polarity... again, preventable.

 

None of this relates to your buzz problem. My suggestion... don't let go of the guitar.

 

Could you come up with a better wiring system for a guitar? Probably. Star grounding in the space of a guitar cavity???? Hmmmm.... The theory of star grounding is well known and in use in many studios for mains power. I don't know how useful it would be with the distances and voltages involved, but there would be nothing wrong in employing star grounding in a guitar. Personally, I think that it owuld be a waste of time and effort, but 99% of my guitars are stock with the occasional replaced tuner or bridge piece or worn nut. I went through every tweaky mod possible int he 1970s and I found my best sounds still came from the stock instruments, and the sounds that I most wanted to get came from stock instruments.

 

My old studio was in a high RF area, and I had trouble with certain guitars and cheap keyboards. I don't know that there is a good answer for you if this really bothers you. Radical changes, like replacing the pickups, will change the sound. You probably don't want to go that route.

 

An 'out there' answer might involve creating a booth with a Faraday cage to protect against RF but again, a lot of work, when just hanging on to the strings is free.

 

Bill

"I believe that entertainment can aspire to be art, and can become art, but if you set out to make art you're an idiot."

 

Steve Martin

 

Show business: we're all here because we're not all there.

 

 

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I wonder why he is having enough humm to make him worry about it? Out of all the guitars I own and the multitude of different pickup styles and antique wiring on some of them I can't say any of them have enough humm to really worry about? This humm problem must be something really bad to make him worry. The kind of humm I think he is experiencing is like what I have run into playing different clubs with questionable electrical grounding or the humm you can get off overhead lighting systems or polarity problems at the amp? or bad cables?
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Eh... if the LP were mine, I could live with the offhanded buzz. Now, the trick is to convince my dad that throwing money at the problem may not be necessary. I'll have him read this thread, perhaps printed out.

 

Xplorer, the guitar is 99.9% stock. Dunlop straplocks were added to make it more stable when strapped on, that's about it.

 

Ellwood, he hasn't played a stage in a couple of years, so overhead lighting systems can't be a problem... yet. :) The amps are plugged in with the ground prong in use.

 

Thanks for the link, Geoff.

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Originally posted by Dr. Taz:

Eh... if the LP were mine, I could live with the offhanded buzz. Now, the trick is to convince my dad that throwing money at the problem may not be necessary. I'll have him read this thread, perhaps printed out.

 

Xplorer, the guitar is 99.9% stock. Dunlop straplocks were added to make it more stable when strapped on, that's about it.

 

Ellwood, he hasn't played a stage in a couple of years, so overhead lighting systems can't be a problem... yet. :) The amps are plugged in with the ground prong in use.

 

Thanks for the link, Geoff.

Right but the point here is it didn't used to buzz..so that is what's pissing off dad!! and I don't blame him if that is the case!
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Originally posted by Scott Fraser:

Hmm, how early? My 56 Strat was unshielded inside until I had the interior painted & foil shielded sometime in the 70s. I had the impression interior shielding was a pretty new thing in the 70s.

 

Scott Fraser

My 60s model Fenders had them. (All of them? Not sure. Certainly all three of the JazzMasters had them. I think that the Jaguar had them. At least one of the Fender XIIs did, and I never tore apart the other XII, the V, or the VI. I can't remember if the DuoSonic had them or not. I don't remember what the 68 Strat had, or tyhe 66. I don't own them anymore.) I've never owned a 1950s Strat, so I can't speak to them.

 

Bill

"I believe that entertainment can aspire to be art, and can become art, but if you set out to make art you're an idiot."

 

Steve Martin

 

Show business: we're all here because we're not all there.

 

 

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Originally posted by ellwood:

I wonder why he is having enough humm to make him worry about it? Out of all the guitars I own and the multitude of different pickup styles and antique wiring on some of them I can't say any of them have enough humm to really worry about? ...

Yeah, I'm assuming it is the area rather than the instrument. Like I said, my last studio was in a high RF area, and I had some real problems with some gear. Made me appreciate the quality build of some of the more expensive mic pres and effects, I can tell you that.

 

I was doing a Presidential gig (political, not governmental) and the console that showed up on the job was not what I speced. The contractor tried to save a buck. One of the Secret Service guys keyed his radio near the sound platform and the pop through the system made everyone scramble. The Major asked me what it was, I told him, and the next thing I knew the Colnel was reaming the contractor, and the board that I speced showed up within the hour. He also threatened to put a 45 slug through the less well sheilded console for me, so that it could not appear on any other gigs. Nice guy. I tried to take him up on it, but they tend to frown on small arms fire in the vicinity of the President.

 

Anyway, the wiring in a passive guitar acts like an antenna, picking up RF that needs to be shunted to ground prior to amplification. The amount of RF being picked up by a stock rig would be dependent upon the amount and strength of the RF, more than the wiring of the guitar.

 

By the way, certan cell phone carriers, like Nextel, can cause problems in the studio or at club consoles. Even the Motorola Razr recieves some sort of signal from 'home' periodically, which I have heard coming over some cheap PA amps or amp/speaker combos.... it is almost a galloping beep, most often heard just before the phone rings but sometimes at random.

 

Bill

"I believe that entertainment can aspire to be art, and can become art, but if you set out to make art you're an idiot."

 

Steve Martin

 

Show business: we're all here because we're not all there.

 

 

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Originally posted by Scott Fraser:

...My 56 Strat was unshielded inside until I had the interior painted & foil shielded ....

 

Scott Fraser

That -can- be an answer but it is not a slam dunk, so I don't like to recommend it. As often as not, it does not solve anything...as we found out with Prince's guitar about an hour before showtime. I felt bad for his guitar tech, but it was the best shot that he had.

 

Bill

"I believe that entertainment can aspire to be art, and can become art, but if you set out to make art you're an idiot."

 

Steve Martin

 

Show business: we're all here because we're not all there.

 

 

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The ground loop video's pretty helpful, thanks.

 

Noise reduction is something I'm well versed in, as I frequently use high gain sounds. Like I said before, my dad's other electrics don't exhibit any problems. Nevertheless, the ground loop tips might help. Thanks for the video links, I'll have to show these to daddy.

 

And, of course, the extended writeups by Bill... but everyone else, too. :)

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Originally posted by Xplorer:

*AHEM*

 

...ground loops.

If the problem was a loop, why would the buzz go away when you touch the strings? Logically, that would provide yet ANOTHER path to ground making yet another loop.

 

The buzz occurs because there is no path to ground. The buzz goes away when a path to ground is provided. That does not sound like a loop to me.

Bill

"I believe that entertainment can aspire to be art, and can become art, but if you set out to make art you're an idiot."

 

Steve Martin

 

Show business: we're all here because we're not all there.

 

 

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Originally posted by Bill@Welcome Home Studios:

Originally posted by Xplorer:

*AHEM*

 

...ground loops.

If the problem was a loop, why would the buzz go away when you touch the strings? Logically, that would provide yet ANOTHER path to ground making yet another loop.

 

The buzz occurs because there is no path to ground. The buzz goes away when a path to ground is provided. That does not sound like a loop to me.

Bill

I hear what you are saying about the extra path to ground, but I don't think that's the case with a guitar related grounding issue. I've ran into this before, I just wanted to make sure you wern't dismissing it as a potential problem.

 

The buzz may not be occuring because of a lack of ground path. Just wanted to stir the pot. Take it or leave it!

What a horrible night to have a curse.
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<>

 

And for balance, a good news story about interior painting & foil: when I toured with The Residents in the 80s they were using an oddly tuned Gibson Melody Maker, which had some pretty wank single coils in it. We were prepping for their first ever major tour with serious management support. Everybody agreed the Melody Maker was way too noisy, so I went out a purchased a Starz Guitarz shielding kit, installed it, plugged it in & it was SO quiet we were all astounded. For once The Residents were speechless. They just said "Thank you", then the rehearsals proceeded.

Too bad about Prince. You'd think he could afford a noise free guitar. Was it one of his custom bodied ones?

 

Scott Fraser

Scott Fraser
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Originally posted by Scott Fraser:

.. Was it one of his custom bodied ones?

 

Scott Fraser

Yes, with EMGs. (??!! buzz?????)

 

I love my 1960 Melodymaker.

 

Bill

"I believe that entertainment can aspire to be art, and can become art, but if you set out to make art you're an idiot."

 

Steve Martin

 

Show business: we're all here because we're not all there.

 

 

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<>

 

That's weird. The EMGs on one of my Steinberger copies are DEAD quiet.

 

<>

 

Does it have that funny tremolo which sort of bends the tailpiece & the arm which never stays tight?

I was in a band for a couple years in the 60s with a guy who had a Melody Maker, but I gotta say I have absolutely no recollection of how it sounded. My sense was it was the Mustang of the Gibson line.

 

Scott Fraser

Scott Fraser
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Originally posted by Xplorer:

The buzz may not be occuring because of a lack of ground path. Just wanted to stir the pot. Take it or leave it!

You are correct, sir. :)

 

Ground or no ground, the problem still occurs with the LP in question. Ground or no ground, every other electric I have access to still buzzes very little or not at all. (Notwithstanding the single coils, of course, but I hardly mind hearing the 60 Hz hum anyway.)

 

Scott Fraser's solution looks interesting... but for now, I think we'll leave the guitar as it is. Unless dad and I do any recording with it soon, it'll remain untouched. I'll see if I can play with it later through my Zoom GFX-5, and nothing else.

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