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Post new topic Single coil hum on a Gibson BR-9 With Plastic Bridge Cover
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Author Topic:  Single coil hum on a Gibson BR-9 With Plastic Bridge Cover
Douglas Schuch


From:
Valencia, Philippines
Post  Posted 11 Jul 2021 4:45 am    
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OK, I bought a basic Gibson BR-9 to fool around with a while back, and it's got the standard hum until you touch the strings - then it's pretty quiet. But here's the problem - that plastic bridge cover!!! I can't ground that and let my hand rest on it to keep it quiet! My technique (or lack there-of) just does not allow me to always have a finger on a string - so the hum comes and goes.

So my question is how have people solved this? I thought maybe a bit of copper wire brought up over the bridge cover (and tucked under the bridge, of course) stuck down with double-sided tape - or maybe some grounding foil brought up over the top? But I bet someone has come up with a cooler, cleaner solution. Ideas?

BTW, this is a rather ugly version of what is perhaps one of the ugliest guitars ever made - so I can't really hurt the looks with a little copper foil....
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Carl Gallagher

 

From:
New York, USA
Post  Posted 11 Jul 2021 5:30 am    
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If you put foil or wire around the bridge cover you will just cause more hum until you touch it.I've never done it to a lap steel but in Fender Teles and Strats I do a complete internal sheilding and connect all grounds to one point inside, called "star grounding".It makes it as quiet as having humbuckers.
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Noah Miller


From:
Rocky Hill, CT
Post  Posted 11 Jul 2021 7:58 am    
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Bad grounding hum and single-coil hum are two different things. You can improve the ground one way or another, but that pickup will always be prone to picking up noise.
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Carl Gallagher

 

From:
New York, USA
Post  Posted 11 Jul 2021 8:49 am    
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I wasnt talking about any "bad grounding" hum, I'm talking single coil hum.Most guitars are not shielded properly from the factory.Most modern Fenders have the back of the pickguard shielded, problem is that shielding isnt grounded at all so it becomes an antenna for outside interference which is then picked up by the single coil pickup.When I shield a guitar the main point is to line the cavity and pickguard with copper foil which creates a kind of faraday cage which is all grounded,important that the pick guard foil is connected to the cavity which is all grounded and deflects any interference to ground and not to the pickup.I started doing this to guitars back around 1995 when my son was playing a weekly open mike gig.His brand new strat was particularly noisy in that environment.The next time he played there everyone wanted to know if I put humbuckers in that strat.When I explained what I did I had about a dozen requests to do their Strats and TelesFor the next year it seemed all I did was shielding jobs.It works.And it has nothing to do with "bad grounds".
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Douglas Schuch


From:
Valencia, Philippines
Post  Posted 11 Jul 2021 2:42 pm    
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Carl, I'd been thinking I'd get the local repair guy to shield the cavity, but suspect it will still hum without contact with the strings. His Tele w/ single coils does, anyway. If so, then i need to find a way to maintain contact with the strings. I think i will try a scrap piece of wire to where I rest the palm of my hand on the plastic bridge cover.

I am still curious how others who play these old Gibsons deal with it.
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Carl Gallagher

 

From:
New York, USA
Post  Posted 11 Jul 2021 3:01 pm    
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Be sure if you have the cavity shielded that they also line the back of the pickup mounting plate and any cover that is on the back,if it has one, is also shielded and that shielding makes contact with the rest of the shielding.The star grounding works to eliminate ground loop hums.When I do a Tele, which has the pots mounted on a metal plate, I insulate the pots with a plastic washer so they dont make contact with the mounting plate then ground the back of the pots individually to the star ground point.
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John Haspert

 

From:
Illinois, USA
Post  Posted 11 Jul 2021 4:34 pm     Gibson BR9
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As for the looks of styling….to each his or her own. I have 2 of them and I have a friend that has one and his brother also has one. Of the 4, we never seem to have any hum issues. We tend to play them in somewhat open spaces and not near fluorescent lights. I play one of mine in a church setting and never have an issue. The only problem I have had is disintegrating plastic tuning keys. I changed both to nickel buttons about 15 years ago…..problem solved.
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John Haspert

 

From:
Illinois, USA
Post  Posted 11 Jul 2021 4:39 pm    
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Duplicate deleted
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Last edited by John Haspert on 11 Jul 2021 8:43 pm; edited 1 time in total
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Jack Hanson


From:
San Luis Valley, USA
Post  Posted 11 Jul 2021 5:35 pm    
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Sounds like there's a strong possibility the bridge ground is broken or missing. Normally, the ground wire is run under the bridge, and is compressed into making good contact once the bridge is torqued down tight.

I have two old BR-9s; one has a factory P-90, and the other has a Sentell P-90 (as shown below). Both are normally as quiet as a church mouse peeing on a cottonball. I can't abide working my picking hand around the stock Gibson fingerrest, so I fabricated new control plates for both of 'em.

When they were opened up, I applied three coats of conductive shielding paint in all the cavities, and installed copper shielding tape to the inside of the new plate and the jackplate. Like night and day.
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Douglas Schuch


From:
Valencia, Philippines
Post  Posted 20 Jul 2021 3:37 am    
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I checked the wiring, and it all looked ok to me - the ground to the bridge is fine - I checked for continuity to a cable plugged into the guitar. A lot of the problem is just the noisy electric and environment here in the Philippines - lots of people have problems with it with single coils. I will try a different approach - going wireless. I use a wireless sytem for my harmonica mics and it works great - just the cheapo ones, about $40. I had to solder that one onto the XLR as the inline female jacks I could get locally were so poor the contact would fail with any movement. So I've got a new one coming in in a few days and will see if disconnecting the guitar from the amp fixes it - I gather it often does.
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Jack Hanson


From:
San Luis Valley, USA
Post  Posted 20 Jul 2021 4:21 am    
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If you have nasty electricity, one of these may help:

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