esto es lo que pone en la pagina oficial del yamaha 771

Amplifier Section Channel 7.2
Rated Output Power (1kHz, 1ch driven) 160W (4ohms, 0.9% THD); 130W (8ohms, 0.9% THD)
Rated Output Power (20Hz-20kHz, 2ch driven) 95W (8ohms, 0.09% THD)
Dynamic Power per Channel (8/6/4/2 ohms) 140/180/210/250W

esta bien?