Ampeg GVT Series GVT15-112 15-Watt 1x12 Guitar Combo Amplifier Dual power modes; Full power - 15 watts RMS; Half power - 7.5 watts RMS Preamp: Tube ( 2 x 12AX7 ) Rectifier: Solid state Power amp: Tube ( 2 x 6V6GT ) Speaker configuration: 1 x 12" Celestion