A very thorough analysis is here, in AES Convention Paper 5335:
https://www.thatcorp.com/datashts/AES5335_48V_Phantom_Menace.pdf
Have a good read.
See page 11.
Both very good read thank you!
Though they only seem to cover the Phantom Power
source protection, i.e. the mixer/audio input side.
I'm on the other side, I have an audio output which may or may not
receive phantom power. Are you saying I should simply implement their proposed protection on my opamp's outputs?
I understand the 1N4004 diodes to the rails, though I am not sure I get what R4, R5, and RG are (I believe they are just part of the audio input - my design is an opamp
output). And what about the capacitor, would my little 6.3V cap not be in risk of damage while the plug is connected/disconnected?
Thank you!