iPhone's that don't have a headphone output don't have a DAC. The dongle supplied has the DAC: https://ifixit.org/blog/8448/apple-audio-adapter-teardown/ Using the DAC in the M0 would be fine but I can't get it to power over USB. Using BT from the iPhone to the M0 then LDAC to the Sony's would be SBC or maybe AAC at best (can't tell) from the iphone, which defeats the purpose of all of this. What digital to LDAC dongle would you recommend? That was my whole reason of buying the M0. Yes, i forgot about the DAC in the Sony's, good point. "Most any dap can output a pure digital signal bypassing their dac" , right, how can i do that with the M0 and get audio via LDAC?