Processor Direct?

[Jodd40]

I have a Yamaha RX-V2200 and there's a Bass Extension button which obviously, turns up the bass. But next two it, there's a Processor Direct button, and I have no idea what it does.

Does anyone else know?

 

[240sx4u]

I am guessing it bypasses as much internal processing as possible such as tone controls. Yammy typically includes that feature.