Please be gentle with me! 🙏

@alan60 

so does the Naim have a DAC?  If not then he should definitely do Bluesound and not mess with his phone as a DAC.  

   Now, purely as a transport, the phone might still be equal to the Bluesound, but it probably won't be, and it is a moot point now as he has purchased the Bluesound

So I will disagree here.  It depends.  The DAC in the Node may or may not be better than the DAC included in the amp.  And the phone may or may not be better as a digital transport into the DAC.  I was using an LG phone in exactly the same way your son is.  I replaced it with a Node because I didn’t want my phone tethered to my system.  There was no obvious sonic improvement 

Your son is probably bypassing the internal DAC in the Bluesound , but perhaps not and he may be using the DAC in the Bluesound.  We know for sure he isn’t using the phone DAC, right?

  As to whether the Bluesound is a better digital transport than the phone, see my earlier answer.  The phone may actually be a good transport.  It depends.  Can’t make the answer more basic than that.

  Now, if you upgrade from the Node into better streamers, I am going to feel fairly certain that the phone will come in second place.  The Bluesound is an entry level product, and a well built phone might match it as a transport, but I haven’t seen a phone that will compete with a higher level streamer than the Node