The THX Achromatic Audio Amplifier (THX AAA) ensures the ultimate no compromise headphone audio experience by delivering the fidelity audio with infinitesimally low levels of noise, distortion, and power consumption. | Three gain settings: The amplifier features three different gain settings for optimal compatibility with all headphones. The lowest gain setting is the most appropriate for sensitive IEMs. | Balanced and single-ended inputs: The amplifier features an XLR balanced input, plus 1/4in and 3.5mm single ended inputs to eliminate the need for adapters. | High grade CNC-milled aluminum with black anodized finish chassis material. | 50 kilohms input impedance. | Connector type: 4-Pin Mini DIN