Update: I successfully converted the port to USB-C! 🎉
I can now connect the headphones directly to my PC using a USB-C cable and use them as a wired headset. Big success for me!

The whole process took about 3 hours because the pads were really tiny for my soldering iron. I guess my previous soldering experience helped a lot in finishing it.

I used a USB-C female PCB port with a sleeve as the new port for the headphones. In the 4th photo, you’ll notice I added a 4.7k resistor so I can use a USB-C to USB-C cable. Without it, the port would only work with USB-C to USB-A cables (4th pic).

Just like in my previous post, I used the +5V and GND pads for power and simply added the data lines to the correct pads for USB connection (6th pic).

If you ever try doing this, disconnect the battery first. I almost destroyed my headphones because I forgot. It suddenly played a loud static sound while I was soldering, and I had to quickly disconnect the battery line before anything worse happened. Luckily everything survived and I soldered it back afterward.

During the first test I wasn’t sure if it would work, but I couldn’t help smiling when the headphones gave the charging voice prompt.

One weird thing I noticed: when connecting it to the PC, a voice prompt appears saying to connect the Nuraphone to a device twice, then it never repeats again. It only happens when the headphones are turned off and used again in wired mode.

Would I do this again? Honestly… I’m not sure, but yeah 😂
It was tiring and a bit scary, but also exciting. At least now I can use and charge it without the proprietary cable.

If you’re in the Philippines and don’t want to DIY, I might be able to help convert it for you. We can work out a small labor cost plus the USB-C port (which is only about $2).

Thanks again to everyone who helped! 

Completing Nuraphone Pinout: SUCCESS 🥳