Measurements and data for the Yamaha RX-V477 are produced by an Audio Precision APx582 test instrument. This is kindly loaned by Audio Precision and provides the best data available from anything on the market today.
Driving an 8 ohm load in stereo, the Yamaha RX-V477 produces 96 watts of power before it hits 0.1% THD+N. When driving a 4 ohm load this falls down to 47 watts of power before 0.1% THD+N. Because of this the Yamaha RX-V477 should not be used with demanding 4 ohm speaker loads, as the amplifier section falls in power quickly.
Frequency response from 20Hz to 20kHz is within +/- 0.043dB in both channels with when putting out 1 watt of power. This is a common listening level for most music, so I use it for this data. It also makes it easy to compare these results to other publications that use the same standard.
With a 1 kHz test tone at 1 watt, there is over 70 dB of dynamic range from the primary harmonic to the 3rd harmonic. 60Hz power supply noise is visible here as well, though it is over 90 dB below the fundamental.
Looking more closely at the spectrum from 0Hz to 1000Hz, the 60 Hz power supply spur is around -100dB below the fundamental, while the 2nd harmonic is the largest at -95dB below the fundamental. The overall noise floor is down at -130dB which is very good.
Here is a -90dBFS test signal, which represents the lowest level signal you will get from a CD or other 16-bit digital source. Here there is over 30dB of range from this low level to the noise spurs at the bottom, and over 40dB between it and the noise floor. Provided your listening room is quiet enough, these lowest level signals will still be clearly audible over the noise floor of the RX-V477 receiver.
On the Audio Precision, the Yamaha RX-V477 performs very well for the price. It isn’t recommended for 4 ohm speakers, but with 8 ohm speakers is will perform well.