The STA‑2A is a dual‑channel, line‑level audio preamplifier. Each channel is identical. The audio inputs are bridged at 20 kΩ and accept either an unbalanced or a balanced audio signal. Gain is adjustable from unity 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 Ω loads.
The STA‑2A features wideband circuitry for excellent phase response, low noise, low distortion and exceptional audio clarity. RDL's SupplyFlex power input configuration is included in the STA‑2A. 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 Ω transformers. The STA‑2A is specifically designed for such installations, and is also ideal in installations requiring high gain in line‑level audio transmission.