Stereo Integrated Tube Amplifier DIY Kit Tube designs rival the sound of high end audio amplifiers that cost 10 times as much! This kit was designed by George Fathauer. Enjoy the thrill of high end audio without going broke and enjoy the satisfaction in building it yourself. Easily built in one evening. Uses 11BM8 tubes included in the kit. Also included pine board for mounting PC board and transformers. Input Impedance: 100K ohms, Output Impedance: 8 ohms, Power Output: 8 watts Frequency Response: 20 to 20,000 Hz, Minimum Input for Full Output: 0.3 V, Total Harmonic Distortion @ 1 W: &lt;1% Kit comes complete will all parts and easy to follow instructions.