Inspired by the classic American rock sound of the original API® 312A, the B12A MKII delivers the high-end sound and rugged quality you’d expect from B.L.A., at an amazing price! The B12A MKII is a single-channel microphone preamp in the style of an API® 312A, and features an upgraded input transformer, higher gain, and lower noise than the original B12A. It also features an output transformer, a Hi-Z input, phantom power, pad, phase, and is housed in a 1U, 1/2 rack chassis.
POWER: flip switch up to turn preamp on, flip switch down to turn preamp off
48V: engage to turn phantom power on, disengage to turn phantom power off
PHASE: engage to adjust input signal polarity by 180°, disengage to leave input signal polarity unchanged
PAD: engage to reduce input signal amplitude by 18dB, disengage to leave input signal amplitude unchanged
GAIN: clockwise rotation yields an increase in output signal amplitude, counterclockwise rotation yields a decrease in output signal amplitude
Hi-Z: engage to use front panel Hi-Z IN as preamp source, disengage to use XLR input as preamp source
Hi-Z IN: input jack for use with high impedance, unbalanced sources (GAIN knob adjusts signal amplitude)