Vintage DUOSONIC models K3 and K4 phonograph record player with 2 tube amplifier and speaker. Original old Sams Photofact manual includes schematic, layout, alignment instructions, voltage & resistance test charts, repair parts list and description. 2 pages. Dated 1947. Duosonic Radio Corp., of Bronx, NY. This manual would make a sensational accompaniment to your classic phono equipment.