Perfect for my situation : using a phantom powered mic AND a non phantom powered mic on a digital interface with two channels where phantom power has to be ON or OFF on BOTH channels. The phantom power supply is a perfect problem solver. I cannot say anything about the circuitry used inside, but i can tell that i did not notice any increase in noise levels, so the PP2B gets the job done nice and clean. ( i am using a very very quiet rhode mic, so when i say quiet, i mean quiet). I like the possibility to use batteries if needed. Construction is made of metallic plates, nothing to say, seems sturdy enough for me, but i usually dont jump or sit on my kit.