The Koss KSC-75 and KSC-35 Bluetooth Mod

This was a quick mod I made to Koss KSC75/35 clip on after a sidetracked discussion on the HeadFi that somehow spiraled into Koss Modding

  • Koss KSC75 or KSC35 or PortaPro
  • Any cheap bluetooth headphone or module (like the KZ one) that you're willing to sacrifice
  • Soldering Iron / Solder / Rosin Flux (optional)
  • 10 minutes of your time.


I took a $5 bluetooth IEM I found at the store and smashed the driver/shells and desoldered the cable.

At the bottom of each Koss KSC driver, remove the faceplate that covers the cable/solder joints. It just pops off.

Prep each bluetooth cable as necessary with rosin flux and solder.

Solder on the bluetooth cable appropriately to the Koss drivers. They are SUPER easy to solder onto.

Pop the covers back on and enjoy!

The cable in the photo is actually not from the original IEM. I messed it up from various projects. The original project that I used this specific BT module/cable was for the Audeze Sine, which I showed detailed instructions with photos here:

Update: photos of solder pads:

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