I would like to do the same however I see two problems:

You would be powering the Explorer from the phone and the phone would need to be told by the Explorer what is required of it (to output a digital signal). As the Explorer is not designed for this it ain't gonna work.

The answer is a device in the middle that would power the Explorer and get the digital signal from the phone and pass on.

As far as I know there isn't currently anything like that and it would start to be more trouble than it's worth.

Sony do some great portable digital DAC's/headphone amps they are expensive but will do what you want out of the box.

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