RDL STA-2A Dual High Gain Line Amplifiers

Dual High Gain Line Amplifiers

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.

Features:

• Up to 24 dB Gain in Audio Lines
• Conversion between Unbalanced and Balanced
• Conversion between High and Low Impedance
• Low-Impedance, High-Current Line Drivers
• Dual-Channel Line-Level Preamplifiers
• High Gain, High Output, High Performance
• RDL SupplyFlex Power Input Configuration

Specifications:

• Amps per STA-2A: 2 identical circuits (stereo or dual mono operation)
• Inputs (2): 20 kΩ balanced or unbalanced
• Input Signal (for +4 dBu out): -20 dBu (-18 dBV) to +18 dBu
• Maximum Input Level: +24 dBu
• Outputs (2): 150 Ω balanced or 75 Ω unbalanced
• Output Signal:
• Balanced: +4 dBu nominal
• Unbalanced: 6 dB below balanced line level
• Maximum Output Level: +25 dBu
• Frequency Response: 10 Hz to 100 kHz (+/- 0.05 dB)
• THD+N: < 0.004% (unity gain)
• IMD: < 0.005% (unity gain)
• Noise below +4 dBu: < -90 dB (unity gain)
• Crosstalk: < -80 dB (unity gain)
• Headroom: > 20 dB (above +4 dBu)
• Gain: Unity +24 / -14 dB (adjustable)
• CMRR: > 60 dB (50 Hz to 120 Hz)
• Power Requirement: GROUND-REFERENCED or FLOATING, 24 Vdc @ 50 mA
• Ambient Operating Environment:0 C to 55 C