How to fit a new Jack Socket to a Les Paul electric guitar
This article is intended to be useful to those of you who own an old electric guitar that has started to crackle and buzz when you move around whilst playing because the jack socket is worn and corroded inside.
You may well have tried squirting switch cleaner lubricant inside it a few times, but it still crackles, pops, disconnects or buzzes when you try to use your guitar. The time has come to change the socket for a new one and banish these problems so you can leap around like Pete Townsend once more (if you are old enough to know who he is) as you play!
All you will need to change the socket is (obviously) a new socket... and you can buy these already attached to a shiny new chromed plate very cheaply so you might as well freshen up the look of your guitar and lose that old dull scratched or rusting jack plate at the same time as changing the socket.... and at least one screwdriver and a soldering iron.
Unsoldering a socket and soldering in a new one isn't difficult or dangerous (unless you hold the wrong end of the soldering iron), and the wiring you are going to be working with only carries a tiny signal voltage from your pickups, so even if the wires drop off or short out, the worst they can do is make a loud buzz through your amplifier!
So, before you begin, you will need a soldering iron rated at about 25 Watts or more... much less will struggle to heat up the solder tags on the jack socket and melt the solder. An old fashioned solder gun will also work, but is a bit clunky to use so close to your guitar. A normal 25 Watt or 40 Watt iron will be ideal, or you can use a temperature controlled solder station type iron if you have access to one.
Make a start by laying your guitar on a suitable worksurface, with some protection between your guitar and the work surface to avoid scratching the back of it. Find a screwdriver that fits the screws holding the old jack socket onto the guitar and undo the screws carefully, being careful not to slip and gouge the guitar.
Once the screws are undone, pull gently on the jack plate and you should be able to pull it in inch or two away from the body of the guitar at least to give you room to work on the wiring.
Now it's important to work out which connection goes where between the guitar and the jack socket, or the guitar will buzz horribly when it's connected to an amplifier!
The cable that comes out of the guitar from the pickups via the volume and tone controls is a screened cable. That is to say it has an inner "hot" core, carrying the very small audio signal from your pickups, surrounded by an insulating layer, which is then completely surrounded in turn with a layer of earthed "screening" wire and finally an outer insulating sheath.
This stops any interference from other electrical items like drills, TV's, radio gear and so on from being picked up by the signal wire, because it reaches the screen first and is harmlessly earthed away.
So, if you actually plug a guitar lead jack plug into the socket as we have done in the photo here, you can actually see which part of the cable goes to what part of the plug via the socket. It's easy to see which part of the cable is the screen anyway, as it is bare, whereas the inner core with the signal on it is insulated right up to the point where it solders onto the socket.
You may find it useful to leave the lead plugged in whilst you unsolder the wires in the next step, as this steadies the socket and gives you a bit of a "third hand"!
Before you begin to unsolder the socket, and having plugged in your soldering iron and left it to warm up for five minutes or so (turn it up fairly high if it has a heat control). Once the iron is good and hot, give the tip a quick scrape with a blade or a wipe on the moistened sponge on your iron stand and then apply a little solder to the tip to tin it freshly.
Finally, before beginning, a few words about the tubular tool shown in the photo on the right. This is a solder sucker.... a small spring operated pump with a trigger that works rather like a bicycle pump in reverse in that instead of pumping air out, pressing the trigger releases the compressed spring and a plunger flies up inside and sucks air (and molten solder) inside it.
If you have one of these, it can be used as you heat the solder tags to remove most of the old solder when you are removing the cable wires, but you can change the socket without using it too.
Apply the tip of the hot soldering iron to one of the solder tags on the socket and the solder there should rapidly melt. If you are using a solder sucker, press its tip lightly into the solder and press the button with your thumb and you should be rewarded with a sharp snap and most of the solder will vanish from the joint.
Either way, the wire should come away, perhaps with a slight pull. Repeat this procedure with the other solder tag and the socket and plate should come away completely and may be discarded.
With luck, the ends of the cable should be fairly neat and intact and brightly tinned with solder ready to re-use, but if not, you may need to remove any excess solder with the tip of your iron and use needle nosed pliers to squeeze any flyaway or frayed strands back into one neat wire.
If worst comes to worst and you need to strip the cable back and bare fresh ends (if there is enough cable to allow this), then use the minimum necessary cable to do this and re-tin the wire ends before the next stage.
Tinning is simply heating the metal and flowing a little solder onto it, which makes the actual soldering of the wire to tag much easier. Take your new socket, apply heat to each tag in turn, and melt a little solder onto it. You should see the molten solder bead you apply lose its bead shape and flow smoothly across the solder tag... avoid blocking the holes in the tag if you want to actually loop the ends of the wires through them before soldering, but otherwise apply enough solder to flow right over the hole and give a smooth rounded blob of solder on each tag.
Then, double checking once more that you are soldering each wire to the right place... apply each wire end to the appropriate solder tag and heat both the wire tip and the solder tag with your iron until they melt and fuse together. Remove the iron and keep a steady hand as the solder sets.... blowing may help here, especially if your fingertips start to scorch!
Do avoid heating the solder joint for too long for two reasons. Firstly, this will start to hurt your fingers and secondly, the solder has an agent in it called flux, which allows it to flow smoothly around and over the metals to be joined. If you heat the joint for too long, the flux burns away (this is the smoke you see rising up) and the joint will become dull and crystalline in appearance, which is poor both mechanically and electrically.
If this does happen, you will need to flow a little more fresh solder (and flux) onto the joint for just long enough to smooth things out again.
Once you have finished soldering the wires and have checked that the joints are smooth and shiny and have flowed nicely over the solder tags.... if you pre-tinned the tags this will be fine... then all you need to do is to refit the socket back into the body of your guitar.
Space inside the body cavity is sometimes very limited, so it may be necessary to gently squeeze the solder tags inwards slightly to allow them to fit inside the guitar. Don't overdo this as you may short out the socket when a plug is inserted!
The old screws that held your jack socket may be re-useable, but are often tatty and marked or may not fit the new socket plate properly, so now is a good time to change them for nice new ones. If the new ones are slightly thicker than the old screws, all the better, as the holes in the wood are often enlarged through being loosened and tightened too many times.
Lastly, when fitting the new screws, double check that all of the holes in the body line up and that the socket is square/parallel to the body when fitting it, and if one or more screw holes are a little out of line when the socket is lined up square, then tighten the other screws first.
You should now have successfully fitted a new crackle free socket to your guitar which should last you for years to come!