17-79 headset squeal
I've just had the same problem with one of my 17-79s which till now worked well.
There's a painfully loud, medium-frequency, feedback-type squeal any time the ANR is switched on.
The problem IS NOT related to the intercom system as the headset squeals when disconnected; the mic isn't part of the active feedback loop causing the trouble because the problem still occurs with the mic unplugged.
I've sent it back to Pilot Comms to look at with the comment that the problem is potentially a flight safety issue because the noise is loud enough to be debilitating.
I wonder whether it's worth continuing this thread for flight safety reasons?