Installing the jack on your DIY guitar kit: a complete FAQ
Whether your kit is solid body, semi-hollow, or hollow, and whether your jack sits on the side, the top, or through a plate, the install breaks down into the same four stages. This post covers every one of them with short video demos from the Guitar Kit World YouTube channel.
Use this as your reference when you get to the jack stage of your build. Jump to the section that matches where you are stuck.
Quick terminology
On guitar kits the words “input jack” and “output jack” are often used interchangeably. It is the same metal connector that accepts your cable. From the guitar’s perspective it outputs signal to the amp, and from the amp’s perspective it receives input, which is why both names exist. In this post we use “jack” to cover both.
- Side jack: mounted on the side or lower edge of the body. Most common on ST-style, solid-body, and semi-hollow kits.
- Top-mounted jack plate: a recessed plate on the top of the body, held by screws. Common on some solid bodies and TE-style kits.
- Through-body jack: on hollow and semi-hollow instruments, the jack assembly is pulled through the body from the inside and secured with a plate and nut from the outside.
Which stage are you at?
- I am building a blank kit and need to drill the jack hole first → Stage 1
- I have a hollow or semi-hollow body and cannot get the wire through to the jack → Stage 2
- I have the jack in place but I do not know which wire connects where → Stage 3
- I am ready to install the jack assembly in my solid body → Stage 4
- I am mounting the jack plate on a semi-hollow or hollow body → Stage 5
Stage 1: Drill the jack hole (blank kit only)
If you bought a blank kit with no pre-cut jack hole, you need to drill it yourself. Mark the location carefully. Most builders put the jack on the lower side of the body where the cable will sit out of the way while you play.
Use a Forstner bit or spade bit that matches your jack diameter. Drill from the outside of the body inward. Go slowly and keep the drill upright.
If your kit came with the jack hole already cut, skip to Stage 2 or Stage 3.
Stage 2: Thread the jack wire through a hollow or semi-hollow body
This is the stage most builders get stuck on. The jack assembly on hollow and semi-hollow kits has to come out through a small hole, but there is no direct path for your fingers. The trick is a simple fishing string.
Use fishing line rather than wire so you do not scratch the finish inside or around the hole.
- Thread fishing line through the jack hole on the outside of the body.
- Reach in through the sound hole or the main cavity and grab the line.
- Tie the line to the jack wire, leaving the knot above the body (not pressed against it).
- Pull the line gently from outside and it will guide the jack wire through.
Stage 3: Wire up the jack (ground and hot)
Every jack has two lugs that you need to identify before soldering anything:
- Ground lug: connected to the inner sleeve of the jack. This is where your cable’s base ring contacts.
- Hot lug (also called active or signal): connected to the arm that holds the cable tip in place.
If you plug a cable into the jack, you can see a rubber ring separating the tip from the base. The tip is the signal side, and the base is ground.
Tin your wires first with a small bit of solder, then connect:
- The ground wire (usually black) to the ground lug.
- The hot or active wire (often green or white, depends on the kit) to the hot lug.
The ground side of the jack is also typically connected to the back of one of the pots (often the tone pot), which provides a common ground for the whole circuit.
The video below walks through the whole process on an XPC kit, including connecting the output from the pickup selector to the hot lug of the jack.
Stage 4: Install the jack in a solid body
Once your jack is wired and tested, the install itself is quick. Drop the jack into the hole from outside the body, align the wires so they do not pinch, and tighten the nut. Do not overtighten or you risk cracking the finish around the hole.
Stage 5: Mount the jack plate on a semi-hollow or hollow body
If you threaded the wire through using Stage 2, the jack assembly is already hanging outside the body. Now you need to secure it with the mounting plate.
- Keep the nut that came on the jack assembly in place on the threaded barrel.
- Slide the jack plate over the threaded barrel from the outside.
- Secure with the second nut on top, then tighten.
This holds the jack flush against the body and keeps the plate in place.
Still stuck?
Drop a comment below and tell us:
- What kit you are building (solid body, semi-hollow, hollow, acoustic-electric)
- Where the jack is mounted (side, top, through-plate)
- What is going wrong (jack will not fit, wires too short, nut will not tighten, etc.)
We and other builders will help you troubleshoot. If you solved a jack install problem on your own build, share what worked. Your experience helps the next builder.