Radio Design Labs STA-2A

The STA-2A is a dual-channel, line-level audio preamplifier. Each channel is identical. The audio inputs are bridged at 20 kW and accept either an unbalanced or a balanced audio signal. Gain is adjustable from unity gain to +24 dB using a 25-turn precision audio taper trimming potentiometer. The output line driver circuits are designed to drive long balanced audio lines into 600 Wloads.

The STA-2A features wideband circuitry for excellent phase response, low noise, low distortion and exceptional audio clarity. The power supply input may be fed from a floating (not ground-referenced) 24 Vdc power source, from a bipolar power supply (+/-12 Vdc or +/-15 Vdc) or from a ground-referenced 24 Vdc power supply.

Many audio products provide optimum performance when feeding into a bridging input, but may not provide the output needed to directly drive low-impedance lines terminated with 600 W transformers. The STA-2A is specifically designed for such installations, and is also ideal in installations requiring high gain in line-level audio transmission.