Transcendent Sound Masterpiece 300B Preamp-Headphone Amplifier. This kit is built but not working and is Bruces older version - not sure what the problem is with the signal out needs to be worked on. Also requires (2) 12AU7 and (2) 300B Vacuum Tubes and power cable not included. I do have (2) EH 300B tubes for sale in another listing if interested. If you dont know what this is and can not work on it, please do not buy it. Original build instructions included! Kit new is $699 plus tax and shipping not built. More from the manufacturer: Transcendent Sound presents the best sounding line stage preamp and headphone amp available, both in one box! Not only that, there is no need to buy a separate headphone amp. Both functions have been fully optimized and neither has been compromised for the other. This breakthrough design incorporates many features.•By using the 300B, all of the sonic magic it is famous for can be added to any system.•High current output stage drives very long interconnect cables. This feature greatly improves the sound of any system as cable capacitance degrades sonic purity.•Integral 10 second time delay mute circuit protects your equipment from turn-on noises.•Dual outputs. One for the main amps and one for the subwoofer amp. •Super high fidelity headphone output.•Vanishingly low distortion.•Essentially noiseless, virtually unobtainable with tube equipment until now. Use it with the most sensitive headphones and experience a dead black, silent background.