The ST-MPA2 contains two identical phantom power circuits and a common power supply input. If only one mic input is to be converted for phantom operation, only one circuit needs to be used. Each circuit has a mic input and a mic output. Phantom voltage appears on each of the mic input terminals. There is no voltage on the mic output terminals. Therefore, the ST-MPA2 can convert any existing mic input into a phantom powered input.
The power supply input terminals may be fed with any dc voltage from 6 volts to 52 volts. The ST-MPA2 has an internal pass transistor-regulator filter circuit which permits this incoming voltage to be adjusted to the desired phantom voltage, up to 92% of the supply input voltage. A multi-turn trimming potentiometer is provided for you to adjust for the correct phantom voltage. A multi-turn trimming potentiometer is provided to set the correct phantom voltage.