Highly versatile and portable, Sound Devices' MM-1 is a single-channel, portable microphone preamplifier with a powerful headphone monitoring function. Proven in mission-critical applications, the high-performance microphone preamplifier uses a transformer-balanced input and output with a bipolar ±15 volt power supply to produce low-noise, low-distortion gain at all switch positions. It features an "unclippable" dual-stage limiter and two-position high-pass filter. Flexible microphone powering provides phantom power at 48 volts or 12 volts and 12-volt T-power. It is powered from two-AA batteries or external 5-18 VDC. The MM-1 is at home in high-definition television production, corporate/industrial environments, radio/television announce booths, and music production. Its headphone monitor is an advantage in applications where communications channels or mix-minus feeds need to be monitored in headphones. The user can monitor both microphone audio and external audio sources in headphones with level control. The MM-1 is designed to be durable. Its aluminum chassis, oversized end panels, machined knobs, and panel mounted connectors assure reliable mechanical operation.