AV Receiver Reviews

This graph shows that the RX-V663’s left channel, from Multi input to speaker output with two channels driving 8-ohm loads continuously at 1 kHz, reached 0.1% distortion at 166.7 watts and 1% distortion at 190.7 watts. Into 4 ohms, the amplifier reached 0.1% distortion at 218.0 watts and 1% distortion at 245.9 watts.

With five channels driven continuously into 8-ohm loads, the amp reached 0.1% distortion at 60.0 watts and 1% distortion at 74.9 watts. With seven channels driven continuously into 8-ohm loads, it reached 0.1% distortion at 47.3 watts and 1% distortion at 57.8 watts.

Yamaha's stated distortion of 0.09% was reached at 46.9 watts with seven channels driving 8-ohm loads. This is roughly half of the 95Wpc specified by the manufacturer, which could be why the AVR seemed to run out of gas at higher listening levels.