Add Switched Headphone Jack to Bop It 2025 Edition

My kids have become obsessed with playing Bop It and the sound of the guy saying "Bop it! Twist it! Pull It!" has become a problem in our house. I added a headphone jack to their toy so they could play it without disturbing anyone. I also discovered that adding headphones made the Bop It a good screen-free activity to keep them entertained while traveling.

There is an existing guide for this but it's 15 years old and is for a different Bop It version. It also does not use a switching headphone jack, which is something I wanted to use on mine. The switched headphone jack automatically switches audio output from the speaker to the headphones when they are plugged in and back to the speaker when headphones are unplugged from the jack.

For this project you will need:

1. A Bop It! Toy (This guide is for the modern white version but it should work with others as well)
2. CESS 3.5mm 1/8 Inch Female Stereo TRS Balanced Socket with Switch
3. 4x 330 ohm resistors
4. Wire
5. Heatshrink
6. Soldering Iron
7. Screwdriver
8. Hot Glue Gun

Remove the screws on the back of the Bop It and slowly pull it apart. Be careful not to lose any small pieces. There are at least two plastic pieces that are easy to lose.

Cut the two white wires that connect the mainboard to the speaker. Try to cut at the midpoint of the wires so that the four remaining wires are all about the same length. This will make it easier to splice later.

Your jack has five lugs:

1. Tip: left earpiece
2. Ring: right earpiece
3. Sleeve: shared return for both earpieces
4. Tip Switch: touches the Tip when nothing is plugged in
5. Ring Switch: touches the Ring when nothing is plugged in

Plugging in headphones pushes the Tip and Ring away from their switch lugs. That's what turns the speaker off.

The diagram shows the CESS jack I used. Lug layouts vary between jacks, so check yours with a multimeter before you solder:

1. With nothing plugged in, use continuity mode to find the two pairs of lugs that beep to each other. The one lug that doesn't beep to anything is the Sleeve.
2. Plug in headphones. Both pairs should stop beeping.
3. Leave the headphones in and switch to resistance mode. Measure from the Sleeve to each of the other four lugs. The two that show a reading are the Tip and Ring (you're measuring through the earpieces). The two that read open are the switch lugs. Each switch lug belongs to the lug it beeped with in #1.

It doesn't matter which pair you use as Tip and which as Ring. The Bop It has one speaker, so the sound is mono.

Once you know which lug is which, solder different colored wires to all five lugs so they're easy to identify. Be careful not to short any of them.

Colors below refer to the wiring diagram above. The two white wires from the board are interchangeable, and so are the two speaker wires, so it doesn't matter which one you use for each connection.

1. Solder one board wire (red in the diagram) to the Tip lug.
2. Solder the Tip Switch lug (yellow) to one speaker wire.
3. Splice the other board wire (blue) to the other speaker wire. This restores the original connection on that side.
4. Solder one end of three resistors together. Connect a fourth resistor from that junction to the Sleeve lug (dark green).
5. Connect the free ends of the three resistors to:
6. the splice from #3 (light green)
7. the Ring lug (orange)
8. the Ring Switch lug (pink)

Cover every splice and bare resistor lead with heatshrink so nothing touches once the case is closed.

How it works

With nothing plugged in, the Tip touches the Tip Switch inside the jack. Audio goes from the board through the Tip, the Tip Switch, and the speaker, then back to the board. The speaker plays the same as before.

Plugging in headphones pushes the Tip away from the Tip Switch, which disconnects the speaker. Audio now goes from the board through the Tip, the left earpiece, the Sleeve, and the resistors, then back to the board. The right earpiece connects through the Ring and its own resistor.

The board is built to drive a speaker, which is much too loud for headphones. The resistors bring the volume down. If it's too loud or too quiet for you, try other values. Higher resistance is quieter.

Don't connect the Sleeve, or any other part of the jack, to the board's ground or the battery negative. Both speaker wires on the Bop It may carry audio, so neither one is a safe ground. Connecting the Sleeve to ground could push steady current through the headphones and strain the sound chip. The headphones should only connect across the two speaker wires, through the resistors, the same way the speaker does.

Before you close the case, test both modes. The speaker should play with nothing plugged in and go silent when you plug in headphones.

Drill a hole using a 15/64 drill bit for the headphone jack. I drilled mine in the bottom half of the case so I could still open the case if I needed to make any further modifications.

Hot glue the headphone jack into place. Make sure to not get any hot glue on the edge of the case as that will prevent you from closing it back up at the end.

It can be tricky to put the two halves back together. Make sure the two small plastic pieces for the Twist It and Pull It mechanisms are in the correct position (you can reference the previous photo for this). Then snap the case back together and reattach the screws.

Hopefully it works and you can enjoy having the option to not listen to Bop It sound effects!