RDL STM-1 Microphone Preamplifier 50DB GainThe STM 1 is a low cost quality microphone preamplifier designed for use in commercial sound and broadcast applications. The compact size makes it ideal where a larger or heavier preamp cannot be used. The high performance circuit provides a fixed 50 dB gain to bring any mic level signal up to the line level range of nearly any line input. The STM 1 supply input is single ended and operates from 24 Vdc. Operation from 12 Vdc is possible with a 6 dB