Yeah a lot of them got husbands though lol . It was like a damn meat market in the field dining rooms . <| sep |> It ' s simply a design decision . Some manufacturers add pre outs variable to work with powered speakers power amps . Others prefer a line out fixed to add just the DAC into a stereo system that already has an integrated amp or seperate pre amp . Generally those with pre outs also mute those rca outs when you either plug in headphones or in case of the fostex push the button while line outs often stay active even when listening to headphones on the built in headphone amp again leaving them on lets you simply mute turn off the integrated amp whereas muting powered monitors or power amps generally means completely shutting them off hence being inconvenient . Some units even offer switches between fixed and variable e . g . some Teac Marantz dacs or 2 sets of outputs . So you see , there are use cases for each of the designs . Just gotta find the right one for you gl .