ART Tube PreAmp. Features ART'S OPL "Output Protection Limiter". VU Meter to measure output level. Tube PreAmp features a 12AX7A Dual Triode Tube. +48 Volt Phantom Power, Switch Selectable. Phase Reverse Switch. Gain (+20 DB) Switch. Input Gain control and Output Level control. Includes power supply. Excellent condition.