Aren't they required to put the maximum power consumption of the device on the back of the unit?
It doesn't add up unless there is an error in their manual.
From the owner's manual of RX-V1800
GENERAL
• Power Supply
[U.S.A. and Canada models] ............................. AC 120 V, 60 Hz
[General and Asia models]
....................................... AC 110/120/220/230–240 V, 50/60 Hz
[China model] .................................................... AC 220 V, 50 Hz
[Korea model] .................................................... AC 220 V, 60 Hz
[Australia model] ............................................... AC 240 V, 50 Hz
[U.K. and Europe models] ................................. AC 230 V, 50 Hz
• Power Consumption
[U.S.A. and Canada models] ................................. 500 W/630 VA
[Other models] .................................................................... 500 W
• Standby Power Consumption
[U.S.A. and Canada models] .................................... 0.1 W or less
[General model] (AC 240 V, 50 Hz) ....................... 0.33 W or less
[Other models] .......................................................... 0.1 W or less
• Maximum Power Consumption [General model only]
6ch, 10% THD .................................................................. 1100 W