The Model 406 Six Channel Headphone Amplifier addresses the requirements for professional headphone mixing. It's a great processor for professional, project and home studio applications. The processor has an output and level control for each set of headphones, and a stereo input for connecting the program source. The 406 is designed and engineered to be durable and rugged, and is an ideal choice when the need for quality audio processing is of paramount concern. The unit is designed for mounting in a standard 19" equipment rack. Specifications: • Input Impedance: 100K ohms • Max Input Level: +18 dBV • Max Gain: 20 dB per channel • Max Output: 300mW per channel • Frequency Response: 20 Hz-30 kHz • Signal-to-Noise: 90 dB • THD & IMD: <0.008% • Power Requirements: 120 VAC, 50-60 Hz, 15VA • Dimensions: 19" x 1.75" x 6" (482 x 44.5 x 152 mm).