Leaves me with only option that is order both and return one of them after a small test period. I'm interested in the Pre Box's possibility to produce better sound vs the single stereo configuration in the Head Box unit. My only question is, is it worth the 80€ price rise.@Fors10 re your 62 ohm headphones, the answer depends on your ears.
To me the Pre Box has more than enough drive, but at least one or two of the metalheads here would definitely disagree.
Oh btw, is the Pre Box compatible with PS4? I'm able to use my current DAC in its' USB port and it'll work as a sound output normally. Would be really nice to have USB in from PS4 and optical in from TV.