Introduction: Simple Bass Guitar From Old Wires, Broken Electronics and Instruments

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About: I'm an avid DIYer and freelance writer who loves writing about repurposing things. There's almost always a way to reuse something that's durable.

Old guitar and bass strings end up in the trash, and so do broken electronics as well as electronic music gear. It’s easy to make your own simple two-string bass guitar (or electric guitar) from parts salvaged from non-working electronics, plus whatever you have lying around to serve as the body of the instrument.

Supplies

Old coated wiring from broken electronics

Old electric guitar strings (Low A and E, ideally) or bass strings

piezo buzzer from an electronic toy that makes noise

wire strippers

solder

soldering iron

heat shrink tubing

an old boat oar, hockey stick, or long piece of wood trim

hollow housing such as Nintendo, old external drive (optional)

1/4” jack

plastic container to hold the jack

utility knife or craft knife

tuning pegs or screw eyes

scrap wood

drill and drill bits

Painter’s tape

hot glue gun

Step 1: Make a Bass Body

Choose something to be your bass (or guitar); ideally something that already has a long neck. In this case, an old discarded wood boat oar was used, but I’ve also used old wood trim I found in the basement and garage. Something around 40” long is perfect. Even an old shovel handle works, but you may only be able to fit one string on it. If you want the bass to resonate a little bit even when not amplifying it, use some form of box for the body part, such as a cigar box or even an old PlayStation or Nintendo housing. (If doing this, something relatively shallow is best, like an old-school Nintendo or an external hard drive housing.

Step 2: Find Some Old Strings

To make a bass guitar, use two old strings from a bass, or the bottom two strings (A and low E) from an electric guitar. I scored a bunch of old strings from a guitar shop; they were going to recycle them through a string company anyway. The strings should be almost as long as your bass body.

Step 3: Source the Buzzer, Jack, and Wires

An old piezo electric buzzer becomes the pickup in this project (or you could just skip all the electrical stuff for a purely acoustic bass). Lots of old toys or cheap alarms use piezo buzzers to make sounds. If you can’t find any old ones, buy them online from a site such as CB Gitty. As for the 1/4” jack (aka “guitar jack”), I have an old effects pedal that was damaged beyond repair, and I got it at a yard sale for almost nothing since it had issues. The wires for this project could be from any old electronics, or even a battery jack on an old cassette player, CD player, you name it. Old computers have plenty of wiring in them also. Some kid-quality musical instruments such as keyboards have the jack and the wiring, and it’s easy to find a broken one or a thrift store item.

Step 4: Figure Out String Placement

For something such as a boat oar bass, two strings is just about ideal because you need room for them to fit over the narrowest part of the instrument. If you’re using some wood molding or something similar, feel free to use up to four strings. Two is ideal for a first time instrument. Lay the strings out atop the instrument to figure out where to drill holes to put the strings through the instrument at the bottom end, lower than the bridge area, and also where to attach them at the top. Mark these locations with a pencil on the instrument. Attaching the bottom parts of the strings is pretty easy; just drill holes in the desired locations so the string fits through, but the ring at the bottom of it will not. Insert the strings through the instrument from the back, then pull them up towards the head of the instrument.

Step 5: Add Wood Scrap String Supports

The strings won’t resonate properly unless they’re slightly raised from the instrument. Set a small piece of wood to serve as the bridge a few inches from where the strings came through the butt end of the instrument. Center it so it looks nice and mark with pencil where it fits on the body. You’ll need a smaller piece of wood scrap, or even the body from a dried up ballpoint pen, for the area above the neck of the instrument, but before the headstock. Tape both pieces temporarily in place with painters tape.

Step 6: Attach the Tuning Pegs

Figure out where the tuning pegs are best placed on your new instrument; look at an actual guitar or bass picture for ideas. Drill holes wide enough to put the post through the instrument so the post sticks through the face of the instrument and the winding pegs are on the back. (The look may vary slightly depending on the tuning pegs you use.) If you’d rather make it even more low budget, use some sturdy screw eyes/ eye bolts instead. These work just fine but it’s a bit hard to get them to stay in tune. Attach the top ends of the strings through their respective tuners and wind them a bit so they tighten somewhat. Make sure the strings go over the bridge and the small piece of wood/pen body near the head stock. Keep tightening slowly and plucking the strings until they ring clearly, but don’t try to tune the instrument just yet because you’ll probably need to make some adjustments. You may need to slide the bridge piece forward or backward a bit to get the best sound. Once you’re happy with the placement of everything, mark the spots where the bridge and top scrap go, then tune the strings to your desired notes (such as Low E and A, from left to right).

Step 7: Wire the Piezo to the Jack

Strip the ends from a piece of coated wire with two strands in it. One end will go from the lead on the piezo to the post on the jack (the stubby post, not the long one). Do the same with the other lead from the piezo, but going to the other stubby post on the jack. The wired setup should be long enough to set the piezo beneath the strings a little above the bridge of the bass, while the jack will go on the back or wherever makes the most sense to you, depending on the item you’re using for the instrument body. Slide two small pieces of heat shrink tubing over the wires, then solder them in place. Slide the heat shrink over the exposed wire areas. Test your wiring by plugging an instrument cable into the jack end, and plugging the other end into an amplifier. Turn the amp on and tap the piezo. You should hear your taps if you wired it properly. Unplug everything when you’re done, then slide the heat shrink over the bare wire bits and melt it in place with a lighter.

Step 8: Make a Housing for the Jack

Make a small housing for the instrument jack by using an old film canister or plastic storage cup with a lid. A thick DVD case may do it as well. I cut mine so the jack fits through the side of the device. I used a craft knife to cut the plastic; heating the tip of the knife first would probably make it cut easily.

Step 9: Figure Out Piezo and Jack Placement

Set your wired piezo pickup somewhere ahead of the bridge area on the instrument, then tape the leads to the instrument temporarily to keep it in place. Figure out where the jack housing should go, such as around the back of the instrument, but in a place where you could easily plug in an instrument cable. Tape that in place as well. Plug an instrument cable into your homemade bass, plug the other end into an amp, and jam. Feel free to move the piezo around a bit to get the best tonal quality. Piezos tend to pick up the noise from your fingers/etc. Once happy with the placement, use glue dots or a dab of hot glue to secure the piezo in place, as well as the jack housing. I like just using tape for the piezo as the sound quality works. Get jamming!

Step 10: Optional Extras/Notes

If you’re making some sort of hollow body to add to the neck of the instrument (as if you’re making a Nintendo or cigar box bass with a wood trim neck), attach the neck through the inside of the hollow box with extra bits of wood and even L brackets for added security. For my cigar box guitar version, I put the wood trim all the way through the end of the hollow body and attached the strings right through the wood trim, as this way, there’s no way the body could ever get damaged from the string tension. I also cut a small sound hold in the lid so it works well acoustically as well. A hollow body also makes it easier to attach the guitar jack, and you won’t need a jack housing this way.

Just about anything sturdy can become a bass or a guitar. You could even use an old computer as the body of your instrument. (I didn’t want to trash my old Commodore 64 or Amiga!)

Feel free to make tiny stringed instruments too. A ukulele, a baby sized guitar, whatever! Use the length of your used guitar strings to dictate the size of the instrument you make. There's also no need to make the instrument electric, so you can skip the entire piezo and jack scenario and add that stuff later if you like.