QSC SPA2-60 
The SPA Series amplifiers from QSC are two half rack 1U, convection cooled power amplifiers delivering two or four channels of 60 watts per channel into 4Ω and 8Ω. These amps can also be bridged to supply 200 watts into 4Ω and 8Ω, and up to 250 watts into 70V or 100V loads making them extremely flexible for Low-Z or High-Z applications. Utilizing an advanced Class-D amplifier design and Universal Power Supply the SPA Series are amazingly efficient allowing them to be convection cooled and are ENERGY STAR® qualified with quiet auto-ramp standby functionality. The SPA2-60 and SPA4-60 are housed in an unobtrusive black painted 1/2 RU chassis with unique mounting hardware enabling rack, table and wall mounting capabilities.
 
Features
Up to 60 watts per channel into 4 and 8 ohms — The outputs of the SPA2-60 and SPA4-60 are designed to provide 60 watts per channel into Low-Z loads
ENERGY STAR® qualified amplifier — The SPA2-60 and SPA4-60 are EnergyStar qualified amplifiers; efficient class-D amplifiers that conserve energy and require no active cooling, so they reduce operational costs.
Bridgeable outputs for higher power — Bridging the outputs of the SPA2-60 and SPA4-60 provide up to 200 watts into low impedance, and up to 250 watts into 70V or 100V providing outstanding flexibility.
Auto-Ramp provides quiet startup and power-down — The EnergyStar Auto-Ramp circuitry ensures quiet and fast power up from Standby and seamless power-down following 28 minutes of inactivity, dramatically reducing power consumption.
Rack-mountable 1U, half rack width enclosure — The SPA2-60 and SPA4-60 can be mounted in 1/2 RU reducing rack space requirements. In addition their clever joining brackets enable easy under-table and wall-mounting.