A professional tube microphone preamplifier is defined by warmth, presence and clarity core elements which make a performance truly come alive. Sister to the ART Digital MPA, the MPA Gold performs to incredibly high standards, and that its tone, functionality and performance will satisfy even the most discerning user. Like the Digital MPA, the MPA Gold features Variable Input Impedance. Variable Input Impedance is intended to optimize the MPA Gold for the widest range of microphones. Variation of the input impedance of a microphone preamplifier changes the load against which the microphone has to push. This variation dramatically alters the performance of a microphone, and creates numerous sonic possibilities for microphone performance. The variable impedance control of the MPA Gold is infinitely variable, as opposed to steps. This allows users much finer control over the tuning of the impedance. The selectable Tube Plate Voltage function delivers a wide variety of tones. The tube circuit is differential, and provides the equivalent of a 300V power supply on the high voltage setting. Not to mention it has very low distortion and noise. The normal setting maintains ART's classic tube sound (warm with smooth overload characteristics). The MPA Gold's unique tube circuitry utilizes two 12AX7A vacuum tubes and renders unsurpassed sonic detail and clarity with the broadest range of microphones. The 12AX7A tube preamplification section provides gain while maintaining the incredible dynamic range of the previous stage and controlled overload characteristics. Condenser microphones, ribbon microphones, dynamic microphones new and vintage all become more versatile and deliver their maximum performance when they interact with the MPA Gold's Variable Input Impedance. You'll discover that your microphones will sound better than ever. The MPA Gold is truly a modern, world-class tube microphone preamplifier, and its audio performance will surely exceed your expectations. Variable Input Impedance For Flexible Microphone Voicing (150 Ohms to 3000 Ohms)Selectable Tube Plate VoltageLarge VU Meters with Range SwitchTube Warmth LED MeterImproved Discrete Class A Input Microphone PreamplifierLower Noise At Low Gains, Wider Frequency Response and Lower THD Than our Pro MPAFront Accessible Instrument Input Jack With Very High Input ImpedanceAutomatically Switches To Instrument Input When You Plug In