Rated output, not maximum.
If you had a 2 volt source and the Yamaha preamp section was just unity gain (no added gain) wouldn't it put out 2 volts?
Input sensitivity / input impedance (1 kHz, 100 W/8Ω)
PHONO (MC) ................................... 150 μVrms / 50Ω
PHONO (MM) ............................... 3.5 mVrms / 47 kΩ
CD (or similar) .............................. 200 mVrms / 47 kΩ
MAIN IN ...............................................1 Vrms / 47 kΩ