Nobsound MX50 SE Dual 2.0 Channel Stereo Digital Power Amplifier Amp DIY Kit 100W+100W This is DIY Kit which need you Assembled it by yourself. (include 2PCB and components.) Lower distortion, better control and resolution Single differential input, single-ended voltage amplifier stage, three-stage inverted Darlington output. The output stage uses the original KTB817, KTD1047 PHILIPS KEC transistor, ST, EVOX producing CBB capacitor.KEMET, TDK monolithic capacitors.