DSD Dire and DSD Cap literally means what they say. It only applies to L7 with Volume Control option. DSD Cap is the default state, for when you want to change volume levels. DSD DIRE is a capless purist option he threw in to show what is possible with only a single cap in the entire pathway. It may have more ultrasonic "noise" but at least the listener can know what near 100% signal purity is like. The caveat is that you first set the desired volume level for critical listening and then select DSD DIRE so as to avoid possible clicks/pops.