RDL TX-AT1S Audio Isolation Transformer w/ SuppressionFeatures: Studio Quality Bifilar Audio Transformer Transient and RF Suppression Terminal Block Transformer Connections Galvanic Isolation 1: 1 Transformer Coupling Transformer to Drive 600 Ohm Line Convenience of RDL TXs Frequency Response: 20 Hz to 20 kHz (+ 0. 1 dB) THD: < 0. 035% ( 50 Hz to 20 kHz, +4 dBu input) 0. 001% (Typ. 1 kHz, +4 dBu input) Input Output Level: +4 dBu, +22 dBu max. CMRR: > 85 dB (balanced input, 50 to 60 Hz)