Amuoc RA 150 Professional Reference Power Amplifier Rated output: 4 ohms: 75 watts RMS per channel 8 ohms: 45 watts RMS per channel 8 ohms: 150 watts RMS, bridged mode Signal to Noise Ratio: &gt;105dB Frequency Response: 10Hz - 70kHz +0, -3dB Distortion: &lt; 0.02% @ 4ohms, 20Hz - 20kHz Input Sensitivity: +4dB for rated output Provides a crisp, clean signal for outstanding performance and extended speaker life Designed for studio use with advanced convection cooling for heat dissipation Stable operation for extended sessions, unaffected by heat-related complications, without the distraction and annoyance of fan cooling Height - 2 RU ( Rack Units ) Rated Output - 45 Watts RMS per channel into 8 ohms; 75 Watts RMS per channel into 4 ohms; 150 Watts RMS ? Bridged Mode ? into 8 ohms