Mesa M6 Carbine 600-watt Bass Amplifier Head Features at a Glance:Black Bronco vinyl covering600 watts @ 4 or 2 ohms (320 watts @ 8 ohms)Trans-Class Power with 8/4 or 2 ohmsImpedance switch for optimum power-to-load performanceAll-tube preamp section with 1 x 12AX7Power amp section with 8 Power MOS..