Phonograph nick and pop reducer. Does not have preamp. INR SYS INVERT/DEFEAT, TAPE MONITOR, SENSITIVITY FADER. AP mod done to improve control calibrating and sensing and filtering the pop or click. Also board has been ruggedized with solder and better caps in power supply. Black brushed aluminum face with wood sides. Minor modification to sensitivity control to lessen audible blanking of audio. Fully serviced, low hours use. 9 + condition. It works good but TNE or Burwen 7000 is a superior design and with my mods it's as good or better than any computer attempt. I worked with Burwen and have upgraded a superior TNE. I am a little famous for this as well as APT products.