GFA-555ms runs on 200 W into 4 ohms, takes both Unbalanced and Balanced inputs and drives your speakers with 40+40 Watts of high performance, ultra low distortion power output all from a neat package. We have engineered an uncompromised circuit design that delivers ultra-low distortion and a crisp dynamic sound. It all adds up to a startlingly vivid and highly impactful musical performance that will put more energy into your loudspeakers as well as control them like never before.