Hand-built by HiFiMan, the EF-6 flagship headphone amplifier provides audiophile quality for the most demanding listeners. Fit and finish hint at the amplifier's exceptional performance under the hood. EF-6 is a hi-end headphone amp with very powerful output. EF-6 can also work as a world-class pre-amplifier. The EF-6 the clear choice for discriminating music lovers seeking a no-compromise headphone amplifier yet priced well below units with comparable performance.