The MP5A is a DISCRETE mic preamp with a DIRECT INPUT on the front panel. The MIC IN is transformer coupled in and out, and has a 20 dB PAD switch (effects both MIC and DIR), a 48V Phantom switch and a Phase or POLARITY switch. The PAD and POLARITY switches effect both inputs.. The inner, or larger (silver) knob sets the mic pre gain and the outer smaller (black) knob controls the output level. We chose the fader control for the outer knob so the gain knob, once set, won't be bumped when adjusting the output level.