"And I thought only the military messed around with such dodgy hardware!"
No such luck. There have been a number of cases, for example, on 747-400's. Some related to newly introduced/designed Radio Control Panels.
All VHF/HF comms go via a single AMU (Audio Management Unit) on the 747-400. However, this box has different internal circuits/power supplies for each crew member (for redundancy). Even so, some airlines have gone a step further and have had a switch installed on the pedestal which allows a direct feed from the Captain's microphone to the #1 VHF Transceiver (bypassing the digital magic/confusion of the AMU).
Rgds.. .Q.