All modern equipment is designed to use less than 0.5w on standby, which is the best way to do it as it allows it to automatically upgrade overnight, and reduce strain on the components of always staring from cold.
NOTE: The 0.5w is a basic setting which all manufacture follow, however if you want additional features to continue running (Network connection etc.) in standby then they will consume more power, which is why you always get a warning when switching these features on.
Some components (Like OLED TVs) have to be left in standby otherwise it will reduce their lifespan, as they perform maintenance program's overnight.
A typical full AV system left in standby with all features on will usually use around 1 unit of power per week.
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