In episode 7 of my video blog I explain how I converted the popular Sony MDR-7506 headphones into wireless headphones using a bluetooth audio receiver from Havit. This is a follow-up video to my previous research in using Bluetooth audio for capturing microphone input on iPhone 7 which doesn’t have the 3.5mm audio input jack.
The Havit audio transceiver module uses the CSR8670 Bluetooth audio chip which is also used in most of the similar devices. It also features a very capable PAM8908 headphone driver and audio amplifier.
The 3.5mm input jack on the PCB can be soldered directly to the three audio signal wires of the Sony MDR-7508 headphones and placed inside the left headphone after drilling the required holes for the on/off switch, the micro-USB charging port and the 3.5mm audio input port which continues to work just like before the modifications: