What's the best way to install a power LED? Simple question I know. I've searched around the lab and have only turned up a couple threads for phantom indicators.
4.7 k resistor 1 watter in series across the 48 mic side. Or 1.5 k resistor in series with your 12 volt relay voltage if using a relay to switch on phantom. No reverse polarity protection needed for dc app.
LED in series with resistor [calculated for the specific voltage] connected to the ground and the output of the regulator. In case something fails you will know if it is the PSU or the audio electronics.