A:Answer From the manufacturer:
"TX-NR575 amplifies accurate, noise-free signal processing with high-current power for dynamic speaker control. The result is pure, rich and authentic sound.
Onkyo's dynamic audio amplification delivers massive power at 170 W/Ch (6 Ohms, 1 kHz, 10% THD, 1 Channel Driven)/ 80 W/Ch (8 Ohms, 20 Hz–20 kHz, 0.08% THD, 2 Channels Driven)."