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  1. #1
    Les Paul Forum Member
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    Les Paul wiring issue

    I bought a Les Paul a few years ago and just noticed the black wire from the toggle switch is not soldered onto the terminal in the volume/tone pot cavity, its simply tied on.
    After comparing the wiring with online schematics I find mine is different.

    I made a schematic below to show how mine is wired, could anyone tell me if this looks ok?
    Thanks all

    https://www.photobox.co.uk/my/photo?...d=501947570899

  2. #2
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    Re: Les Paul wiring issue

    Photobox will not let me play. Which LP model do you have?

    No wires should be "tied on" in any way.

  3. #3
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    Re: Les Paul wiring issue

    Quote Originally Posted by rick c View Post
    Photobox will not let me play. Which LP model do you have?

    No wires should be "tied on" in any way.
    Ive soldered that wire now.
    Its a 2001 Gibson Les Paul Standard honeyburst and supposed to be completely stock. I will try another site does this work?

    https://imgur.com/PpJBmUZ

    https://pasteboard.co/IkFLHLV.jpg

    https://www.image-story.com/OiE6W

  4. #4
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    Re: Les Paul wiring issue

    If your wiring is exactly as shown, you are missing grounds. I think you've just missed the ground loop that connects all four pot backs to each other., usually a wire that loops around the cavity. The volume pot top connection points should also be grounded. Your guitar wouldn't work properly if this wasn't the case.

  5. #5
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    Re: Les Paul wiring issue

    Quote Originally Posted by rick c View Post
    If your wiring is exactly as shown, you are missing grounds. I think you've just missed the ground loop that connects all four pot backs to each other., usually a wire that loops around the cavity. The volume pot top connection points should also be grounded. Your guitar wouldn't work properly if this wasn't the case.
    I noticed the lack of ground wires too but isnt that because the pots are mounted on a metal plate and the plate acts as the grounding? Im only assuming this.

  6. #6
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    Re: Les Paul wiring issue

    Quote Originally Posted by Gadge View Post
    I noticed the lack of ground wires too but isnt that because the pots are mounted on a metal plate and the plate acts as the grounding? Im only assuming this.
    Yes, if the pots are on a metal plate they ground to that so no need for a ground wire, there should be a ground wire from the tailpiece which usually connects to a terminal tag in the middle of the plate. As pointed out the top tags on the volume pots and the bottom tags on the tone pots should be grounded by soldering to the back of the pots (I assume that is the case as if they were not neither the volume or tone pots would work correctly)

    In what way do you think it is different from other schematics? The way you have shown it is correct for "modern style" Gibson wiring, the other common method is "50's style wiring", with that method the only difference is that the capacitors connect to the middle lug of the volume controls instead of the outer ones.

  7. #7
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    Re: Les Paul wiring issue

    Quote Originally Posted by PaulD View Post
    Yes, if the pots are on a metal plate they ground to that so no need for a ground wire, there should be a ground wire from the tailpiece which usually connects to a terminal tag in the middle of the plate. As pointed out the top tags on the volume pots and the bottom tags on the tone pots should be grounded by soldering to the back of the pots (I assume that is the case as if they were not neither the volume or tone pots would work correctly)

    In what way do you think it is different from other schematics? The way you have shown it is correct for "modern style" Gibson wiring, the other common method is "50's style wiring", with that method the only difference is that the capacitors connect to the middle lug of the volume controls instead of the outer ones.
    Yea there is a wire on the plate leading to the tailpiece but its not soldered to the terminal in the middle its soldered to the top of the Neck volume pot.

    So basically this plate also helps to clean the wiring up, less ground wires needed.

    Thats my mistake I kept finding 50's wiring diagrams, it took me ages to find stock wiring and that one had more ground wires but I know why now, thanks for your help guys. Im actually about to convert the pickups from 2 to 4 conductor. Ive always left Les Pauls stock but im tired of not having those other tones I dont have that are very useable.

  8. #8
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    Re: Les Paul wiring issue

    Quote Originally Posted by Gadge View Post
    Yea there is a wire on the plate leading to the tailpiece but its not soldered to the terminal in the middle its soldered to the top of the Neck volume pot.
    That's fine, as long as it connects to ground it doesn't make any difference where.

    Quote Originally Posted by Gadge View Post
    So basically this plate also helps to clean the wiring up, less ground wires needed
    Yes, and it simplifies the manufacturing process as the pots can be assembled to the plate and wired up before mounting to the guitar. Newer Gibson's have taken it a step further with everything being mounted to a printed circuit board and the pickups plug into the board with multi-pin connectors. No soldering during assembly presumably prevents any accidental soldering iron burns to the finish

  9. #9
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    Re: Les Paul wiring issue

    Quote Originally Posted by PaulD View Post
    That's fine, as long as it connects to ground it doesn't make any difference where.



    Yes, and it simplifies the manufacturing process as the pots can be assembled to the plate and wired up before mounting to the guitar. Newer Gibson's have taken it a step further with everything being mounted to a printed circuit board and the pickups plug into the board with multi-pin connectors. No soldering during assembly presumably prevents any accidental soldering iron burns to the finish
    Ive seen those, I was going to buy one with the push/pull pots but im considering using switches instead but its not the conventional way to go so theres not much wiring help out there. I was going to wing it but I dont want to electrocute myself. I deffo prefer switches the more I think, its cleaner, I already have 4 switches, easier to do, original pots remain, and takes advantage that im a pickguard man and leave them on so I can hide the switches.
    Last edited by Gadge; 06-29-19 at 10:43 AM.

  10. #10
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    Re: Les Paul wiring issue

    Well there is no danger of electrocuting yourself, the only voltage in a guitar is that generated by the pickups which is in the millivolt range. The worst that could happen if you wire something incorrectly is that it wont work, it's not going to cause any harm.

    There should be plenty of wiring diagrams around for using push-pull pots so if you want to use discrete switches instead it is just a case of running the wires that go to the switch on the back of the pot to your discrete switches instead.

  11. #11
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    Re: Les Paul wiring issue

    Quote Originally Posted by PaulD View Post
    Well there is no danger of electrocuting yourself, the only voltage in a guitar is that generated by the pickups which is in the millivolt range. The worst that could happen if you wire something incorrectly is that it wont work, it's not going to cause any harm.

    There should be plenty of wiring diagrams around for using push-pull pots so if you want to use discrete switches instead it is just a case of running the wires that go to the switch on the back of the pot to your discrete switches instead.
    I always knew that but then I heard Keith Relf asked a friend to fix his guitar wiring and when he got it back it electrocuted him to death.

    The problem is I want to do several mods so I dont know how to wire them all together, separate yes but I assume it will be different if I combine all of them, considering my wires are going to a switch instead of the pot its probably going to be very different. (phase, coil tap, series/parallel)

    Ok I just realised why pots are better because its less signal degradation. That explains why everyones using pots.
    Last edited by Gadge; 06-29-19 at 03:33 PM.

  12. #12
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    Re: Les Paul wiring issue

    Quote Originally Posted by Gadge View Post
    I always knew that but then I heard Keith Relf asked a friend to fix his guitar wiring and when he got it back it electrocuted him to death.
    I'm sure there are lots of stories about how he got electrocuted, some of them might even be close to the truth but not that one! The only way you can get a shock from a guitar is if it is plugged into a faulty amplifier where the chassis is live and you are touching both the guitar strings and some other metallic object that is earthed at the same time. You can rest assured that there is nothing you can do to your guitar wiring that could cause it to be a shock hazard

  13. #13
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    Re: Les Paul wiring issue


  14. #14
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    Re: Les Paul wiring issue

    Quote Originally Posted by PaulD View Post
    I'm sure there are lots of stories about how he got electrocuted, some of them might even be close to the truth but not that one! The only way you can get a shock from a guitar is if it is plugged into a faulty amplifier where the chassis is live and you are touching both the guitar strings and some other metallic object that is earthed at the same time. You can rest assured that there is nothing you can do to your guitar wiring that could cause it to be a shock hazard
    So how many volts pass throughout the guitar when live?

  15. #15
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    Re: Les Paul wiring issue

    Quote Originally Posted by rick c View Post
    Thanks. Looks like the push pot is the way to go then.

  16. #16
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    Re: Les Paul wiring issue

    Quote Originally Posted by Gadge View Post
    So how many volts pass throughout the guitar when live?
    If you mean what voltage is present in an electric guitar then under normal circumstances the answer is none (other than a few millivolts of signal voltage when a string is plucked). If the guitar was plugged in to a faulty amplifier which had no safety earth connection and also had a fault that made the chassis live then the guitar strings would be at the same voltage as the chassis, what voltage that would be would depend upon the nature of the fault but in a worst case scenario it could be mains voltage or it could be the HT voltage that the amplifier operates on (typically around 350v for a valve amplifier). On it's own this would not give you an electric shock, you would also need to be in contact with something else that is conductive and provides a path to earth for current to flow and give you a shock.

    Strictly speaking voltage does not "pass through" anything, voltage is the difference in potential between two points, if two points of different potential are connected together by a conductive path then an electric current will flow (measured in amps or milliamps). Hence the reason why a bird can land on a high voltage power line and not get electrocuted, there is no conductive path to earth so no current flows.

  17. #17
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    Re: Les Paul wiring issue

    Quote Originally Posted by PaulD View Post
    If you mean what voltage is present in an electric guitar then under normal circumstances the answer is none (other than a few millivolts of signal voltage when a string is plucked). If the guitar was plugged in to a faulty amplifier which had no safety earth connection and also had a fault that made the chassis live then the guitar strings would be at the same voltage as the chassis, what voltage that would be would depend upon the nature of the fault but in a worst case scenario it could be mains voltage or it could be the HT voltage that the amplifier operates on (typically around 350v for a valve amplifier). On it's own this would not give you an electric shock, you would also need to be in contact with something else that is conductive and provides a path to earth for current to flow and give you a shock.

    Strictly speaking voltage does not "pass through" anything, voltage is the difference in potential between two points, if two points of different potential are connected together by a conductive path then an electric current will flow (measured in amps or milliamps). Hence the reason why a bird can land on a high voltage power line and not get electrocuted, there is no conductive path to earth so no current flows.

    Thanks for that but as always I cant get my head around current, volts, amps and all those symbols on multimeters, im getting there slowly and I kind of get it but never fully understand what im doing, im just following guides.
    If you knew how many videos ive watched on how electricity works and still cant grasp it you would call me an idiot.

  18. #18
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    Re: Les Paul wiring issue

    Don't feel bad Gadge: Very simply, a regular, non-active (no batteries!) guitar generates a tiny current when the strings vibrate over the pickup magnet and coil. This tiny current goes to your amplifier where the it is amplified and modulated and then a powerful signal is sent to the speakers. Even an active guitar, with batteries, only boosts and/or modulates the signal leaving the guitar; still just a tiny signal in terms of voltage/amps leaving the guitar. As stated earlier, the only way to get a shock from a guitar is for the amp to have a very serious fault that has not been isolated via good grounding; a live, high voltage source is directed the wrong way to the guitar and is looking for a ground. There's nothing you can do to guitar wiring that makes it more dangerous to the player.

  19. #19
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    Re: Les Paul wiring issue

    Quote Originally Posted by rick c View Post
    Don't feel bad Gadge: Very simply, a regular, non-active (no batteries!) guitar generates a tiny current when the strings vibrate over the pickup magnet and coil. This tiny current goes to your amplifier where the it is amplified and modulated and then a powerful signal is sent to the speakers. Even an active guitar, with batteries, only boosts and/or modulates the signal leaving the guitar; still just a tiny signal in terms of voltage/amps leaving the guitar. As stated earlier, the only way to get a shock from a guitar is for the amp to have a very serious fault that has not been isolated via good grounding; a live, high voltage source is directed the wrong way to the guitar and is looking for a ground. There's nothing you can do to guitar wiring that makes it more dangerous to the player.
    Its cool to work on the guitar now with no worries but I still dont get electricity, like why doesnt a laptop electrocute me when they are not grounded. Im currently making an earth wire (from the wall sockets earth to the USB socket) to stop it humming when I plug any audio gear into it but there is a risk the laptop or audio equipment could be damaged but without the earth wire its unusable.

    Whats REALLY weird is I swapped the USB lead for a different one and the hum was gone, but later it came back, so how the hell does laptop temporarily ground itself with absolutely no ground anywhere?
    Last edited by Gadge; 07-18-19 at 11:19 AM.

  20. #20
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    Re: Les Paul wiring issue

    The reason your laptop (or any other electrical device for that matter) doesn't electrocute you is that the manufacturers have a vested interest in designing them not to do so, mainly so that they can avoid lawsuits but also so they can continue to sell you more of their devices! Joking aside laptops run on low voltage DC, typically 12 - 18v which is supplied either from the battery or via a mains power supply, the design of the power supply is such that the laptop itself is isolated from the mains and there is no high voltage present. Not all devices need a ground connection in order to be safe, it depends upon the design of the product.

    As for your hum problem I wouldn't recommend running ground wires from the USB socket as you suggest, although this is unlikely to cause any damage or hazard it is not a recommended procedure. Without knowing the details of your setup and what you have connected to the computer it is difficult to diagnose the problem but it sounds like a ground loop of some sort. First thing to try would be to see if the problem goes away with the laptop running on it's battery and not connected to the mains. If you can let me know exactly what you have connected to the computer I might be able to help more.
    Last edited by PaulD; 07-18-19 at 05:16 PM.

  21. #21
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    Re: Les Paul wiring issue

    Quote Originally Posted by PaulD View Post
    The reason your laptop (or any other electrical device for that matter) doesn't electrocute you is that the manufacturers have a vested interest in designing them not to do so, mainly so that they can avoid lawsuits but also so they can continue to sell you more of their devices! Joking aside laptops run on low voltage DC, typically 12 - 18v which is supplied either from the battery or via a mains power supply, the design of the power supply is such that the laptop itself is isolated from the mains and there is no high voltage present. Not all devices need a ground connection in order to be safe, it depends upon the design of the product.

    As for your hum problem I wouldn't recommend running ground wires from the USB socket as you suggest, although this is unlikely to cause any damage or hazard it is not a recommended procedure. Without knowing the details of your setup and what you have connected to the computer it is difficult to diagnose the problem but it sounds like a ground loop of some sort. First thing to try would be to see if the problem goes away with the laptop running on it's battery and not connected to the mains. If you can let me know exactly what you have connected to the computer I might be able to help more.
    Nice one, I knew that bit about the transformer thing knocking it down from 240 to 12v, this is what im curious about the bit about the design and how we know how high a voltage needs to be before it needs an earth.

    Yes the laptop is quiet when running on battery and noisy with the power plug inserted.
    Before reading your post I already tried the grounding plug idea and its working ok, totally silent no hum or hiss.
    Heres a picture of my setup:

    https://pasteboard.co/IoCGENb.png

  22. #22
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    Re: Les Paul wiring issue

    Quote Originally Posted by Gadge View Post
    this is what im curious about the bit about the design and how we know how high a voltage needs to be before it needs an earth.
    It's actually nothing to do with the voltage but depends on the design of the appliance. There are basically 2 types of appliance, in simple terms if an appliance has exposed metal parts that could potentially become live in the event of a fault then it needs an earth connection to make it safe. If a device is designed in such a way that there are no exposed metal parts that could become live (sometimes referred to as double insulated) then an earth is not needed. When an appliance is operating normally the safety earth connection plays no part in it's operation and no current flows through it, it only does anything if a fault develops which causes some metal part of the appliance to become live, then a current would flow through the earth connection and cause the fuse or circuit breaker to blow and prevent a dangerous situation.

    Going back to your hum issue, many laptop power supplies do have an earth connection, in these the earth is not needed as a safety earth but it connects the negative side of the DC supply to ground which is exactly what you are doing with your ground wire. The ground wire as you show it in your diagram will not cause any harm to anything but if you wanted a more permanent solution you could look for a suitable power supply that has an earth connection, should be easily available from eBay or other places, you would just need to make sure that it is compatible with your laptop and that it has an earth pin on the mains plug.

  23. #23
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    Re: Les Paul wiring issue

    Quote Originally Posted by PaulD View Post
    It's actually nothing to do with the voltage but depends on the design of the appliance. There are basically 2 types of appliance, in simple terms if an appliance has exposed metal parts that could potentially become live in the event of a fault then it needs an earth connection to make it safe. If a device is designed in such a way that there are no exposed metal parts that could become live (sometimes referred to as double insulated) then an earth is not needed. When an appliance is operating normally the safety earth connection plays no part in it's operation and no current flows through it, it only does anything if a fault develops which causes some metal part of the appliance to become live, then a current would flow through the earth connection and cause the fuse or circuit breaker to blow and prevent a dangerous situation.

    Going back to your hum issue, many laptop power supplies do have an earth connection, in these the earth is not needed as a safety earth but it connects the negative side of the DC supply to ground which is exactly what you are doing with your ground wire. The ground wire as you show it in your diagram will not cause any harm to anything but if you wanted a more permanent solution you could look for a suitable power supply that has an earth connection, should be easily available from eBay or other places, you would just need to make sure that it is compatible with your laptop and that it has an earth pin on the mains plug.
    Its a very old laptop so I will just make sure the next one is earthed and use this earth cable for now, in fact im gonna make sure everything I buy is earthed now. Thanks man.

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