The STA-1 is a dual-channel line-level preamplifier with bridging inputs, adjustable gain or loss, and low-impedance outputs. Each of the two identical circuits is both an electronic line transformer and a line amplifier. Hook up the STA-1 just like a pair of audio transformers with gain. True dc amplifiers produce unsurpassed audio clarity, high common-mode rejection, ultra-low distortion and low noise. The STA-1 is perfect for most line amplification, impedance or balanced/unbalanced conversion.