Stereo Power Amplifier manufactured by Adcom, Aragon, Audio Research, Carver, Crown, Denon, Dyanco, Earthquake, Fisher, Harman Kardon, Kenwood, Klipsch, Krell, Marantz, Mark Levinson, Mcintosh, NAD, Onkyo, Pioneer, Revel, Rotel, Sansui, Sherwood, Sony, Sunfire, Teac, Technics, Velodyne, or Yamaha