Marantz has been designing and making amplifiers for more than 65 years, and for 40 of those the products have reflected expertise of Ken Ishiwata. Now, to mark his four decades with the company, the PM-KI Ruby amplifier has been developed and tuned by a highly experienced engineering team led by KI himself. . Features a fully discrete two-stage design with separate power supplies for the pre-amplifier and power amp — plus, a moving coil/moving magnet phono stage complete with Marantz Musical Premium Phono EQ circuit and Marantz HDAM technology for signal purity and exceptional audio quality. PM-KI Ruby is built on a vibration-resistant double layer chassis with thick aluminum panes for rigidity and features a laser-engraved Ken Ishiwata signature to commemorate his legacy.