Charles, part of the puzzlement here is because of a misreading of the setting; it isn't actually a "straight effect" setting, it's a control that gives a choice between "straight" and "effect". Straight feeds two channel to main speakers without further processing and likewise for multi-channel. Effect allows for various surround effects to be applied(or cancelled by simply switching to straight). Pure direct, as was pointed out, goes beyond straight in also shutting off all video circuitry and the front display.
