Bluetooth Headphones Conversion




Introduction: Bluetooth Headphones Conversion

About: It all began with legos... And now, I'm a woodworking lover, and DIY passionate! -- Mackero por conviccion, Windowsero por obligacion, admirador de Unix, y amante de CMD

Hi everyone!
(There is an improved version here!)
A couple years ago, I got this headphones for free, buying a shirt.

And of course, after using them daily, the cable began to fail.

So, I leave them inside a box, and a few months later, searching for a bluetooth headphones, (after losing each one of my last headphones 'cause cable issues, i must learn something right?) I discover a "bluetooth hands free car kit".

Suddenly, it all came to me, and the idea for this instructable was born!

Step 1: The Materials and Tools

So, I bought the cheapest bluetooth hands free I could found (the first one came broken, that's why there are some holes and pieces of plastic missing inside the headphones, from the previous attempt) and, besides it, every tool and material I allready have it around. Some piezes are not that common, but they come from dispossal computers, and broken cables that any friend could have.

Here is the materials list:

Here is the tools list:

  • Utility Knife
  • Soldering Iron
  • Drill

Step 2: Taking Everything Apart

Ok, first, we need to take apart the speaker on the side where the cable come out

To prevent some damage between the magnet, the audio wires and the bluetooth, i put some isolaton tape over it.

Then, I split the plastic over the bluetooth chip. No more to do here

Step 3: Soldering the Headphones to the Bluetooth Module

We have 2 speakers and only one cable, wich means we have a left audio wire, a right audio wire and one ground wire, wich conects both speakers on series.

The audio jack from the bluetooth, has 3 pins from left to righ:

1st left audio, 2nd right audio and 3rd ground.

The first and second pins could be used on any order, as long as the third pin remains ground

Step 4: Making the Charging Cable

The hole for the audio cable was so small, that I could'n fit a female micro USB Port, so i came with the idea of making a specific charging port, using a USB cable and some front panel cables.
Before I explain the process for tha cable, feel free to improve my solution, as long as you keep 2 cables to conect the positive and ground sides of the chargin micro USB port, to a 5V power source.


This cable comes in 2 parts, one inside the headphone to conect the bluetooth charging micro usb port to the audio cable hole (Lets name it Panel Cable A), and another one for the USB cable conversion (Lets name it Panel Cable B)

Panel Cable A

  • Cut the plastic of the micro USB cable until the pins are exposed
  • Solder one side of the Panel cable to the 1st pin of the micro USB cable, and the other side to the last pin
  • Using som epoxy clay, lock the panel cable tip inside the audio cable hole

Panel Cable B

  • Cut the paper clip to get 2 pieces of 3/4 of an inch.
  • Fit the paper clip pieces inside the holes of the panel cable.
  • The USB Cable has up to 4 wires, 1 red (mostly positive) and 1 black (mostly ground). Solder each one to the front panel cable.
  • Isolate the wireswith shrink tube

Also, this is a good time to drill a hole on the headphone cover, to gain access to the on/off switch

Step 5: Fitting the Parts

The Panel Cable A needs enough space to connect into the Bluetooth, and turn back to the audio cable hole. Use the utility knife to cut some material.

Also, in my specific case, the space between the magnet and the back of the headphone case, was so small, that i need to put the batery next to the bluetooh.

After everything is align, use som epoxy clay to fix the parts inside the case.

When it's dry, simply close the speaker on the case to keep everything inside.

Step 6: One Button to Rull Them All!

Now that everything is inside, we need some easy way to push the On/Off switch.

I came with the idea to use some transparent acrilyc with a small hole to cover the chip, and a screw inside the hole to push the button.

Also, I add a thin layer of epoxy clay over the screw head, to prevent the switch to get stuck inside.

Later, I place it over the hole and glue the acrylic piece in place.


And thats all! I hope you enjoy this Instructable, to recycle some old headphones.

Please leave a comment or a suggestions, to improve it.

Step 7: Finished!!!

We're done!

The bluetooth battery last around 6/7 hours of continuous playing.

Press the On/Off Switch 10 seconds to enter "discovery mode" and connect your phone to "DL-Link"

Press it around 3-5 seconds to turn it on or off.

Hope you guys like it!

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    19 Discussions

    Everything is good, but... I don't like charging system like that. I think micro usb socket would be better.

    2 replies

    Hi Kostan_Kettch. I already publish and improved version of this project, with a new charging port.

    Hope you can see it.

    I Agree with you. But I haven't enough space to fit a Female Micro USB port, and I don't want to make bigger holes on the plastic. Hope you give it a try!

    Great project but how loud is it? It may need a power amplifier if we desire it to be loud since the bluetooth receiver is designed to be connected directly to an auxiliary input, so it may have just a pre-amp with few microwatts of potency, and the impedance gotta be observed when connecting the device's output to 4/8 ohms speakers or it'll distort.

    5 replies

    Most headphone speakers are more on the order of 16->32 Ohms, so lack of volume would be more prevalent than distortion (overdrive). However, the high impedance could definitely cause the preamp to lose its magical blue smoke if the input signal is driven too high, but since it's an isolated, self-supplying circuit (not hardwired line in, but 2.4GHz carrier + audio signals decoded to "line in"), that's unlikely to be an issue here. :-)

    Hopefully I can get my synchronized Bluetooth surround sound speakers working soon - synchronizing the signals is HARD... :-)

    Thanks PaulA23, hope to see your project soon.

    Hi! First of all, thanks for your sugestion! To be honest, i don't know much about impedance oohms values cause i'm some kind of "learn as you build" guy.

    Either way, i promise you: They sound Amazing! using them with my cellphone so far, I haven´t any kind of distortion, even on the top volume.

    I promise I made some video of it, working, to give you some ideas about it.

    Also, I've allready made some changes to the original project, so I be publishing the improved version soon.

    That sounds great, rachesv99! ;)

    Thank you!

    Hi! As I promised, here is the video:


    I was in the US NAVY for several years as an Aviation Electronics Tech, but I can promise you that I've learned more from "learn as you build" than any electronics teaching I've ever had!! :-)

    I've converted several old headphones to Bluetooth - in fact, many friends & family laugh because I'm always saying "hey, let's put Bluetooth on it" almost every time I see something electronic, lol! The charging port & amplification issues are valid concerns (mainly due to charging polarity & speaker impedance), but let's face it: if the speakers or electronics get fried, then you've already gained more in knowledge & experience than the ~$10 cost of the project. :-)

    If you do version 2, I suggest using the internals of a Bluetooth speaker instead of the hands-free kit. The electronics are still fairly small, but give you a better amplification circuit for the impedance (resistance) of your headphone speakers. Most cheap ones combine left & right into a single channel, but it's fine for headphones, & you can buy them for $10 USD new @ Big Lots & WalMart (or your local "super" store). As for charging port, you can use a small audio jack, then re-use the old headphone cord as the charging cord - USB 2.0 charging spec is only 2.5 Watts (500mA @ 5Volts). :-)

    Excellent job - you made your idea a reality, & that's what matters!! :-)

    1 reply

    Hi! I haven't bought yet the bluetooth speaker, but I already published the same project with a few improvements. Hope you like it!

    Thanks to booth of you!

    Please, if you can, give it a try!

    This is really amazing. the blue colour led is so cool :D

    i am gonna try it.

    1 reply

    Love to hear it! Please do, and share your project!