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Shielded Cable On-Line


Lammas Day

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My BFG is noisy, background messy.

 

I've not got TONNES of experience here, but from what research I've done on a BFG it's all about the inadequate shielding of it's innards.

 

I can pick up copper tape easy enough on eBay, but I'm having trouble finding some shielded wire to replace the unshielded wire currently connected to the killswitch.

 

What am I looking for? Do I just need shielded 2 core 2.5mm cable?

 

 

(before anyone says the obvious, I live in the middle of nowhere, driving to the nearest guitar shop would cost me about £10 in petrol)

 

can anyone send a link?

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Guest farnsbarns

My BFG is noisy, background messy.

 

I've not got TONNES of experience here, but from what research I've done on a BFG it's all about the inadequate shielding of it's innards.

 

I can pick up copper tape easy enough on eBay, but I'm having trouble finding some shielded wire to replace the unshielded wire currently connected to the killswitch.

 

What am I looking for? Do I just need shielded 2 core 2.5mm cable?

 

 

(before anyone says the obvious, I live in the middle of nowhere, driving to the nearest guitar shop would cost me about £10 in petrol)

 

can anyone send a link?

 

A DIY solution may be to strip a foot or 2 of coaxial tv arial cable, cut off a couple of feet of the outer braid and slide it onto the outside of the kill switch wire and solder it to an earth (ground) point.

 

Also, remember that copper tape sheilding will need to be earthed (grounded) as well.

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A DIY solution may be to strip a foot or 2 of coaxial tv arial cable, cut off a couple of feet of the outer braid and slide it onto the outside of the kill switch wire and solder it to an earth (ground) point.

 

Also, remember that copper tape sheilding will need to be earthed (grounded) as well.

 

Woh there... there was me thinking this was going to be simple, it probably will be, but can you help by explaining a little more?

 

So if I was to replace or cover the kill switch cable I'd need to cover the red and white wires here...

 

284278_241933392504119_100000623816335_821527_5976350_n.jpg

 

and regarding the earthing (ground) point, am I correct in thinking that this silver wire is a grounding point...

 

281533_241933309170794_100000623816335_821525_5951751_n.jpg

 

If not can you point me in the right direction for a grounding point?

 

So once all the cavities are nicely covered in copper foil, how would I go about grounding it - I thought (ignorantly so perhaps) that just the back of the pots touching the foil would be contact enough - is this not so?

 

----------------------

 

Currently there is a buzz to the guitar when ever there's any form of distortion, if I touch my finger to any metal point on the guitar it stops dead quiet. This is a REAL remedial question - but does the earth travel down the input lead to the amp?

 

THANKS

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Guest farnsbarns

Woh there... there was me thinking this was going to be simple, it probably will be, but can you help by explaining a little more?

 

So if I was to replace or cover the kill switch cable I'd need to cover the red and white wires here...

 

284278_241933392504119_100000623816335_821527_5976350_n.jpg

 

and regarding the earthing (ground) point, am I correct in thinking that this silver wire is a grounding point...

 

281533_241933309170794_100000623816335_821525_5951751_n.jpg

 

If not can you point me in the right direction for a grounding point?

 

So once all the cavities are nicely covered in copper foil, how would I go about grounding it - I thought (ignorantly so perhaps) that just the back of the pots touching the foil would be contact enough - is this not so?

 

----------------------

 

Currently there is a buzz to the guitar when ever there's any form of distortion, if I touch my finger to any metal point on the guitar it stops dead quiet. This is a REAL remedial question - but does the earth travel down the input lead to the amp?

 

THANKS

 

Hmm, not familiar with kill switches, I would start with the copper tape shielding, and yes, good contact with the pots will be a satisfactory earth.

 

The humm is almost certainly from an external source (mains humm) and I believe that would probably be enough. If not then I would shield all 3 of the wires from the kill switch since I cannot tell what is what.

 

Don't forget to add shielding to the inside of the cavity cover.

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So..if the hum STOPS when you touch the bridge or strings, and HUMS when you lift your hands off the guitar, it is properly grounded.

 

Also, does this guitar have the humbucker in the bridge and the p-90 in the neck? Check the amount of hum you get comparing the 2 pups. If the hum is primarily coming from the p-90 neck, it may be impossible to eliminate that.

 

Check these things first, as you may not actually have a problem. And also, knowing where the source is will help to know what to do that might actually make a difference.

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Guest farnsbarns

So..if the hum STOPS when you touch the bridge or strings, and HUMS when you lift your hands off the guitar, it is properly grounded.

 

Also, does this guitar have the humbucker in the bridge and the p-90 in the neck? Check the amount of hum you get comparing the 2 pups. If the hum is primarily coming from the p-90 neck, it may be impossible to eliminate that.

 

Check these things first, as you may not actually have a problem. And also, knowing where the source is will help to know what to do that might actually make a difference.

 

Good point, I was assuming from the op that this was a known issue with this model. My p90 equied LP humms a little, if I turn away from my amp it is masively improved.

 

I have been thinking about winding 2 coils onto the single bobin of a p90 but it would essencially not be a p90 any more.

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Good point, I was assuming from the op that this was a known issue with this model. My p90 equied LP humms a little, if I turn away from my amp it is masively improved.

 

I have been thinking about winding 2 coils onto the single bobin of a p90 but it would essencially not be a p90 any more.

Yup...P-90's hum a lot. About twice as much as a strat of tele pup.

 

Thats a good idea, if I was a pickup winder man, I might try it. SEARCY give a good comment about balenced coils vs unbalenced in a thread I don't know how to link, but essentially, the coils must be MATCHED in output in order to eliminate hum. The further away from matched they are, the more hum.

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Yup...P-90's hum a lot. About twice as much as a strat of tele pup.

 

Thats a good idea, if I was a pickup winder man, I might try it. SEARCY give a good comment about balenced coils vs unbalenced in a thread I don't know how to link, but essentially, the coils must be MATCHED in output in order to eliminate hum. The further away from matched they are, the more hum.

 

...dang i find my thread packing up and drifting off over my head.

 

SOOO back to me sticking my finger in a hole to make a bad noise stop :) yeah, it's the original set up, so poi'haps it could be the P90... hmm hum...bucking, yeah, didn't put 2 & 2 together there.

 

There was some talk about the distressed finish on the metal work not allowing good connections, so grinding/filing it off where the tailstops connect to the body stops it, I did this, and it did help. But like I said, the moment there's distortion/overdrive/GAIN on the guitar it's all over the shop.

 

right cheers, I'll give all the above a go

 

tar

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...dang i find my thread packing up and drifting off over my head.

 

SOOO back to me sticking my finger in a hole to make a bad noise stop :) yeah, it's the original set up, so poi'haps it could be the P90... hmm hum...bucking, yeah, didn't put 2 & 2 together there.

 

There was some talk about the distressed finish on the metal work not allowing good connections, so grinding/filing it off where the tailstops connect to the body stops it, I did this, and it did help. But like I said, the moment there's distortion/overdrive/GAIN on the guitar it's all over the shop.

 

right cheers, I'll give all the above a go

 

tar

 

Yeah, sorry, these things often get derailed.

 

Start by using copper tape in the cavities, make sure, if you are using more than one piece, that each piece makes good contact with the next...

 

Fold the edge of the top piece over so that it contacts the top of the piece below it. In other words, the glue wont make good contact (or any contact probably) so every piece of tape needs it's top side to be in contact with the top side of another piece.

 

Put tape on the bottom of the plastic covers too.

 

If you do that first and report back.

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Yeah, sorry, these things often get derailed.

 

Start by using copper tape in the cavities, make sure, if you are using more than one piece, that each piece makes good contact with the next...

 

Fold the edge of the top piece over so that it contacts the top of the piece below it. In other words, the glue wont make good contact (or any contact probably) so every piece of tape needs it's top side to be in contact with the top side of another piece.

 

Put tape on the bottom of the plastic covers too.

 

If you do that first and report back.

Have you tried that on your R6? I have a special that I did some shielding to, and it actually got worse.

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Have you tried that on your R6? I have a special that I did some shielding to, and it actually got worse.

 

No, but that's because it's as you'd expect with p90s, I may have made it sound like it's quite bad, it's very live-able. I have a 60W Marshall stack in a 10 foot by 8 foot studio with ancient wiring and slightly damp walls. The electricity supply comes via my land ladies house and she has a swimming pool with a huge filter pump motor and we have only one ring main in the house for all the outlets so the heating, the fridge, the freezer, the washing machine, the dishwasher and the tumble drier all generate noise in my electricity too. If I go somewhere with modern wiring and use a smaller amp, not at guitar hight and position the amp just right the hum is really barely noticeable. Further more I quite like the rough and ready sound and honesty of my set up anyway.

 

I would say if it got worse it may be down to a bad earth (ground) in your special because the shielding basically catches electrons in the air (radio/RF signals) and sends them to earth (ground) before they get into the signal. If it got worse my logic would say that maybe the earth (ground) is leaking into the signal?

 

I don't know your level of expertise which may be far greater than mine so please don't take this the wrong way, just where my logic takes me.

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No, but that's because it's as you'd expect with p90s, I may have made it sound like it's quite bad, it's very live-able. I have a 60W Marshall stack in a 10 foot by 8 foot studio with ancient wiring and slightly damp walls. The electricity supply comes via my land ladies house and she has a swimming pool with a huge filter pump motor and we have only one ring main in the house for all the outlets so the heating, the fridge, the freezer, the washing machine, the dishwasher and the tumble drier all generate noise in my electricity too. If I go somewhere with modern wiring and use a smaller amp, not at guitar hight and position the amp just right the hum is really barely noticeable. Further more I quite like the rough and ready sound and honesty of my set up anyway.

I see..Always on the lookout for stuff I may not know.

 

Having nearly always used strats, I have always had hum. Thing is, I take it for granted and I am used to it. Sometimes, others will notice when I don't, so what is a problem for some or annoying to some might not even be an issue for others. And, also, what is perceived as loud hum by some could easily be not loud to another, depending on the circumstances or who it is.

 

I am TOTALLY with you on the "rough and ready" thing. To me, nothing says "here it comes" like when the amps are humming in preparation for the next tune. I mean, to me, the sound of amps humming is the sound that the tune is about to kick off.

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FARNS;

 

No offence. I am actually quite skilled at grounding from my stereo/turntable days, and I have applied that to guitars at times.

 

There definitely is an art to it. And you are correct in that adding a bunch of random shielding is a recipee for more hum. I have found that when the source is FROM the pickups, shielding the rest of the guitar makes it worse. All you do there is transfer the potential to make the source of the noise more than what it was.

 

For example, if you take a strat pup and add a ribbon of shielding around the coils (that do not touch the coils or anything else) and connect that to the output jack or the back of the pot, you get less noise. (I think the tone suffers a bit though.) But shield the control cavity with shielding paint, and there will be MORE hum.

 

I haven't tried to much with the p-90, but the one I did try and shield the pup is louder humming than the one without. Also, with the different grounding that happens using braided wire as opposed to the shielded harnsess (as in the difference between a vintage wired and a modern one) I haven't gone much beyond sound quality.

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BFG,

Greetings, I have been staring at your wiring for a while and am wondering if it has been rewired incorrectly. Maybe I am missing something from the pictures but From what I am seeing the 3 way pickup selector switch is wired to ground twice. Once from the ground lug (currently Red Wire) and the middle lug (Between the two brown wires) that should act as the "main out" for the switch (currently Yellow Wire). If I am seeing this correctly I think your main issue is that the guitar signal is being fed back into the output across the ground path.... I'm kinda surprised it works at all.

 

I would try twisting the red and white wire together so they look like a braid and will act as its own shield and then reverse the connections where the yellow wire and the red wire are connected on the 3 way pickup selector switch. I bet this solves the majority of your issue.

 

I'm also wondering about how the output is is going to the the tone control but need to stare at it a bit longer...

 

Good luck....

 

 

Andy

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BFG,

Greetings, I have been staring at your wiring for a while and am wondering if it has been rewired incorrectly. Maybe I am missing something from the pictures but From what I am seeing the 3 way pickup selector switch is wired to ground twice. Once from the ground lug (currently Red Wire) and the middle lug (Between the two brown wires) that should act as the "main out" for the switch (currently Yellow Wire). If I am seeing this correctly I think your main issue is that the guitar signal is being fed back into the output across the ground path.... I'm kinda surprised it works at all.

 

I would try twisting the red and white wire together so they look like a braid and will act as its own shield and then reverse the connections where the yellow wire and the red wire are connected on the 3 way pickup selector switch. I bet this solves the majority of your issue.

 

I'm also wondering about how the output is is going to the the tone control but need to stare at it a bit longer...

 

Good luck....

 

 

Andy

I think you may be right, but we MUST be not seeing something about how the switch is wired, because I don't see how it would work.

 

What it appears, the tone control being a master, is first. Then, it runs to the 3 way, and the kill switch is just a shorting switch.

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Guest farnsbarns

BFG,

Greetings, I have been staring at your wiring for a while and am wondering if it has been rewired incorrectly. Maybe I am missing something from the pictures but From what I am seeing the 3 way pickup selector switch is wired to ground twice. Once from the ground lug (currently Red Wire) and the middle lug (Between the two brown wires) that should act as the "main out" for the switch (currently Yellow Wire). If I am seeing this correctly I think your main issue is that the guitar signal is being fed back into the output across the ground path.... I'm kinda surprised it works at all.

 

I would try twisting the red and white wire together so they look like a braid and will act as its own shield and then reverse the connections where the yellow wire and the red wire are connected on the 3 way pickup selector switch. I bet this solves the majority of your issue.

 

I'm also wondering about how the output is is going to the the tone control but need to stare at it a bit longer...

 

Good luck....

 

 

Andy

 

 

I think you may be right, but we MUST be not seeing something about how the switch is wired, because I don't see how it would work.

 

What it appears, the tone control being a master, is first. Then, it runs to the 3 way, and the kill switch is just a shorting switch.

I think I know what you've missed, that's a kill switch, not a 3 way pup selector. In a way it is supposed to "not work". I looked at it and concluded that it bleeds all of the signal to ground when it is engaged, not how I would implement a kill switch.

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I think I know what you've missed, that's a kill switch, not a 3 way pup selector. In a way it is supposed to "not work". I looked at it and concluded that it bleeds all of the signal to ground when it is engaged, not how I would implement a kill switch.

 

Farns,

I understand it is a kill switch ( and how they work) but I believe the way it is wired back to the 3 way switch is incorrect. Almost guarantee it.....

 

The KillSwitch has to have a signal in, a signal out, and a ground. The 3 way switch has to have an input from each pick-up ( the brown wires from the switch to the pots) and a main out put ( the middle 2 connectors on the 3 way switch that are connected together ( currently this is the yellow wire going to ground which is incorrect) What he has now is essentially the Kill switch outputting directly to the output of the jack via the white wire on the tone control which is tied to the jack output ( which is fine) but the input to the killswitch ( the red wire is being grounded and it shouldn't be)

 

Think output to input path.....

 

Pickups output to the input leg on the volume controls.

 

The output travels through the middle lug of each volume control to one side or the other ( the inputs) of the 3 way pickup selector switch ( the brown wires) the middle lug connector becomes the main output which in this case should be sent to the input of the kill switch ( the red wire)

 

The white wire is the output of the kill switch and is tied to the output jack on the tone control.

 

The tone control is an "open" Variable resistor since it doesn't have a leg shorted to ground. The capacitor is on the middle output of the tone control to filter off high end.

 

The Heavy white wire from the kill switch that is being grounded on the back of the volume pot is going to ground so when it is engaged thus shorting out what would be the signal in and out ( red and white) by sending those signals directly to ground.

 

Trust me this isn't wired right....

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BFG (TAR)?

 

How is it going? I hope all this technical stuff isn't overwhelming you or scaring you off.

 

We here to help if you need it. I have to leave for work soon, but me and the guys on this thread have a history of sticking around to help "fix" stuff when it needs fixing.

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All I can say is listen to Andy. He knows his stuff and clearly sees something I don't. I'll stand down. Andy is your man.

Andy is the man, but that does not mean you have to "stand down". Not only can we learn something, but we can still contribute (as you have).

 

You just might catch something we miss.

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I wouldn't freak out and do anything to the wiring just yet...it may be fine.

 

I have wrapped my head around it, and from the photos I see, the switch APPEARS to be wired wrong (confirming what ANDY has said), but, if it is wired that way, it would not work at all. The pups would be shorted, and there would be no sound.

 

I am pretty sure what we THINK we are seeing the way the switch is wired is not what we are seeing.

 

Getting a little deeper, the overall way of doing this is not how I would do it (or most) and it looks goofy and overdone, especially at the kill switch. From my experience, this is typical of Gibson special editions with different wiring schemes. They often aren't very well thought out, and chances are they do NOT have a diagram for it.

 

I think if it works, you might leave it as it is. If it doesn't, it can be solved, but if you feel you want to "improve" whatever weak points it may have, I think you will have to rewire it differently, but I couldn't say how much you would notice if you did or how much it would improve.

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I wouldn't freak out and do anything to the wiring just yet...it may be fine.

 

I have wrapped my head around it, and from the photos I see, the switch APPEARS to be wired wrong (confirming what ANDY has said), but, if it is wired that way, it would not work at all. The pups would be shorted, and there would be no sound.

 

I am pretty sure what we THINK we are seeing the way the switch is wired is not what we are seeing.

 

Getting a little deeper, the overall way of doing this is not how I would do it (or most) and it looks goofy and overdone, especially at the kill switch. From my experience, this is typical of Gibson special editions with different wiring schemes. They often aren't very well thought out, and chances are they do NOT have a diagram for it.

 

I think if it works, you might leave it as it is. If it doesn't, it can be solved, but if you feel you want to "improve" whatever weak points it may have, I think you will have to rewire it differently, but I couldn't say how much you would notice if you did or how much it would improve.

 

Did you wrap your mind around the fact that the tone control has no short to ground??? msp_biggrin.gifmsp_flapper.gif I believe this would allow the signal to bleed back through the ground circuit eusa_think.gif

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Yes, "stand down" was a bad choice of words. It was a tounge in cheek "old chap, what Ho, tally Ho and all that" turn of phrase.

 

 

Sorry if I came across wrong. Was in a hurry and just trying to make a clear point.... You da man!

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Did you wrap your mind around the fact that the tone control has no short to ground??? msp_biggrin.gifmsp_flapper.gif I believe this would allow the signal to bleed back through the ground circuit eusa_think.gif

The jack is wired to the tone pot, with the (ground, neutral, whatever) to the back of it.

 

ALL the pots are wired together on the back (yellow) and the neutral from the pups as well. that means if the switch is wired to from the center (as it APPEARS?) in the photo to the back of the pots (yellow) that would mean the hot and neutral of the pups would be a short.

 

I (we?) are missing something or not seeing the way the switch is wired. It should NOT work.

 

I love a good mystery.

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