Fiio k5 pro desktop dac and headphone amp is a high power headphone amp with a quality dac built-in, designed to improve the sound of music from a computer, out to headphones or powered speakers. the most common application is usb from a computer or phone, out to headphones. With 1.5 watts out at 32 ohms and low/med/high gain levels, the k5pro is a great match with planar headphones and almost any dynamic headphones, including sennheiser and beyer harder to drive models, up to 300 ohms. connect the line out to powered speakers, using the k5pro as a dac, for improved sound quality. The built-in dac decodes high res files and the volume control backlight changes colour to indicate the music bitrate.