What I did was buy a GoPro Camera, a GoPro Combo Cable so I can charge the GoPro with USB and get audio to it.
You just need a cable to plug into your intercom, I bought one that plugs into the end of the headset and into the aircraft. The other plug into the GoPro combo. Just can't find the cable online at the moment. No dubbing needed, sounds pretty clear as well. You pick up all the radio traffic which is handy as well.
One more thing, I had to change the housing so it wasn't the waterproof one so I could plug cables in the side.