The SPA4-100 four channel amplifier delivers 100 watts rms per channel into 4 or 8 ohms; the four channels can also be bridged in pairs, each pair providing up to 200 watts rms into 4 or 8 ohms. The SPA4-100 bridged pair channels can be switched into 70V or 100V direct drive mode providing up to 350 watts rms into a 70V or 100V output; when in 70V or 100V mode the 80Hz highpass filter is automatically engaged. Features Up to 200 watts per channel into 4 and 8 ohms — the outputs of the SPA4-100 model are designed to provide up to 100 watts per channel into Low-Z loads. ENERGY STAR® qualified amplifier – The ENERGY STAR qualified SPA amplifiers employ an efficient class-D design to conserve energy and reduce operational cost. Bridgeable outputs for higher power — Bridgeable outputs for higher power – Bridging the outputs of the SPA4-100 will deliver up to 350 watts into 70V or 100V when bridged. Auto-Ramp provides quiet startup and power-down — The ENERGY STAR auto-ramp circuitry ensures quiet and fast power up from standby and seamless power-down following 25 minutes of inactivity, dramatically reducing power consumption. Rack-mountable 1U, half rack width enclosure — The SPA amplifers can be mounted in 1 RU, 1/2 rack space, and their clever joining brackets enable easy under-table and wall-mounting