The TA-N9000ES fully embodies the ES ideal of "power & purity." Power comes in the form of 115 watts into either 4 ohms or 8 ohms (x5, 20 -- 20,000 Hz, 0.013% THD). Purity comes from Sonys remarkable Direct Ground Drive power supply, anti-resonant Frame& Beam construction with an additional, inner monocoque chassis, and vibration resistant sf Fin™ heat sinks. To accommodate the widest range of demanding home theater environments, the TA-N9000ES offers BTL operating modes for 4, 3 and 2 channels, in addition to the 5-channel mode.