The STM-3 is a quality low-noise microphone preamplifier designed for use in surveillance, commercial sound, broadcast, and recording where higher than normal gain is required. The STM-3 is very flexible, with gain adjustment from 45 to 75 dB, two balanced or unbalanced outputs, and available phantom supply input. Its low-distortion and low-noise performance make it the best choice, even when larger preamps could be used. The single-ended supply input range is from 24 to 33 Vdc. Operation from 12 Vdc is possible with a 6 dB reduction in headroom. Each output drives high or low impedance loads.