Thanks to Mike K for the motivation to get this project going. The idea was to come up with a DIY adapter that was easy enough to make to allow me to use my Bose QC2 headphones in the airplane. Because I’m not a Part 135 or Part 121 operator, I don’t need TSO, even in certified aircraft. The price of the old Bose QC2 headsets is plummeting on eBay and used sets can be found for under $50. If you include the cost of the pieces for the DIY headset kit, you can have a very nice, lightweight set of noise cancelling aircraft headphones for much less than even the cheapest sets out ther today.

• Wireless Conversion Kit Short Cable for Bose QC15 QC2
  • https://www.amazon.com/gp/product/B01M28NFOJ/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1
• USB Reading Lamp
  • https://www.amazon.com/gp/product/B00D2ZDY2Q/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1
• 1/4″ Plugs for Patch Cables
  • https://www.amazon.com/gp/product/B00CX6FDPG/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1
• .206 Microphone Plug
  • https://www.amazon.com/gp/product/B00OGL7IQI/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1
• Total Cost = $37.18

• For the electronics, the big components are:
  • Electret Mic – I used EM-9745UN ($2.19)
  • NPN Transistor – 2N5089 ($0.54)

• If you want to get fancy, I ordered a nice 4 conductor extension cable for a nicer fit and finish:
  • https://www.amazon.com/gp/product/B01K3WYNKC/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

The Schematic for the Mic Circuit is Below for Reference