As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ON CLIMB-OUT A BURNING ODOR WAS NOTICED IN THE CABIN, THE PILOTS HEADSET THEN CUT-OUT. AN UNEVENTFUL EMERGENCY LANDING WAS CARRIED OUT. UPON INSPECTION THE AUDIO CONTROL AMPLIFIER WAS FOUND TO HAVE FAILED INTERNALLY CAUSING THE SMOKE ODOR.