Another simple project from diyaudio.com.\n\n\n\n\n\nI have this playing through a pair of Grado SR225e headphones and it sounds fantastic. It has two selectable modes by switching jumpers. "Choice of resistor or CCS plate loading for preferentially lower distortion or softer clipping."\n\nAbout the blue LEDs: "using a blue LED to bias CCS and light the tubes ." If they become annoying, I will black them out. Meanwhile, I will try it their way. \n\nNow I need to fashion a box for this too. Fun stuff!