I deleted my initial post after reading a little about the P5.
It seems to me that for playing Spotify files there would be no benefit to an external DAC unless the DAC in the P5 is really bad and even then, only if there are input options in the P5 that would allow you to bypass the internal DAC.
It seems to me that for playing Spotify files there would be no benefit to an external DAC unless the DAC in the P5 is really bad and even then, only if there are input options in the P5 that would allow you to bypass the internal DAC.