Originally Posted by
QRC3288
It's quite easy (this applies for 77A/74A...not sure about the new 77D). You just pull out the three-pronged plug (which is located either on your right or left, about elbow height when sitting upright), and then make sure you have a two-pronged adapter (the third bottom prong that comes with the CX headphones is for powering the noise cancelling system).
The two prong adapter that is provided with your BOSE set will NOT work due to cowling around the J headset input. buy a separate adapter that goes straight in (not in the shape of an L as the BOSE one is because the L is the one that won't fit).