The studio-reference and fully balanced Musical Fidelity MX-HPA is the result of decades of experience of making high quality headphone amplifiers. Its technical performance is stunning. Typically distortion from 20 Hz to 40 kHz is less than 0.005%. This is serious stuff. Signal noise ratio is better than 120dB ('A' weighted). Needless to say, frequency response is ruler-flat from 10Hz to 20kHz (-0.1dB), and the amp is capable of a short-term peak of 10 watts (for one cycle). It has two gain positions; 18dB (8X) and 24dB (15X). Inputs are either balanced or single ended. It automatically converts single-ended inputs to balanced.