Hi Lloyd,
Attached is a circuit that I just drew up. It shows you how you could use your external power supply as phantom power for the Cortado. As you can see, pins 2 and 3 of the XLR jack are used for both signal and phantom power. The signal (an ac voltage) is superimposed on the DC phantom power. The signal is the separated from the DC via the two 47uF/63V capacitors. Make sure they are rated for a voltage higher than your phantom power. The XLR pins (2 and 3) are separated from each other via the two 6.8K resistors. The two 100K resistors are to give the caps a place to drain when nothing is plugged into the XLR cable. You may need to increase the value of these (to has high as 1M) if the Cortado has a hard time driving the signal past them (ie the output signal is lower than you want). Let me know if you need more explanation or if you have other questions.
Good luck.
-Brach
