The Extron XPA U 1004 SB and XPA U 2002 SB are four and two channel Energy Star qualified audio power amplifiers with flexible channel pairs that can deliver 100 watts to 400 watts per channel into 8 ohm, 4 ohm, 70 volt, or 100 volt loads. A rotary switch on the rear panel of the amplifier makes it quick and easy to select the desired output mode. The convection cooled, plenum rated enclosures do not require empty rack spaces for ventilation and include rack mount hardware. Both models feature Extron’s highly efficient advanced Class D amplifier design with defeatable auto-standby, fast wake up from standby, and our patented CDRS – Class D Ripple Suppression. XPA Ultra SB models also support remote volume and mute control using an Extron VCM, VC or select MediaLink controllers.