Old phones as streaming sources

I've used an older android phone as a remote control for streaming Spotify but not as a host for local digital files. The real issue you run up against is that most of the streaming services update their apps with some frequency and eventually the phone (after no longer receiving firmware updates) can't run the latest streaming app.

Of course, I don't use Apple Airplay which forces you to stream tvia the phone so I avoid the issue of having the phone being the source when I'm at home. There, the phone is just a remote and volume knob at that point since I have some Denon home smart speakers that are connected directly to the home wi-fi and I use the onboard DAC. Which is fine for background music. 

I have started using iphone (13) as a streamer a long while ago before purchasing Ifi ZS as a dedicated streamer. When playing music through an iphone and an external DAC, its SQ is better than the following different setups:

iphone > window laptop/Mac Air > iphone w/ Apple dongle > iphone internal DAC

When compared with the Ifi ZS, I am pleased to report that, through the same external DAC, the iPhone sounds almost on par with the Ifi in my system (Buchardt S400 ii / Parasound amp / Schiit DAC). The Ifi ZS has a bit more body in mids but iphone is no slouch. The bass is as weighty (try China Hok-Man Yim: ’Poems of Thunder’ eg), high ends/mids are as neutral, soundstage is as wide, and the noise floor is dark as well. When streaming from Qobuz in particular, the app works much better than a UPnP application like MConnect for Ifi.

I continue to use the Ifi ZS simply because I prefer playing music from an SSD / HDD. I collect hi-res files and don’t stream as much.

@lanx0003 I’ll just say my experience was way different.  I thought using my iPhone into my DAC using Qobuz sounded really good.  Then I brought up my old Oppo player to use as a CD transport into my DAC and playing CDs totally eclipsed the performance of streaming with my iPhone — not even close, and to say I was disappointed and discouraged is an understatement.  Several people here strongly suggested I get a separate streamer, so I bought an iFi Zen Stream (with their iPowerX power supply) and the performance immediately leapfrogged CDs and went to another level entirely.  Again, not even close.  Comparing playing through the Zen versus direct with the iPhone was like listening to hi res vs. MP3.  Again, not even close.  Not saying you didn’t hear what you heard at all and I’m sure you did, but it is in stark contrast to my experience so thought it worth sharing.

It's strange. While it is understandable that the perception of sound quality is subjective, it cannot deviate too much. I wonder if this has something to do with the settings?

https://www.makeuseof.com/how-to-improve-sound-quality-on-iphone/

@bruce19 

here’s someone who actually measured the results of using a phone as a streamer vs several other options.  His takeaway, no surprise, is that the DAC matters a lot.  Jitter rejection and noise filtering at the DAC can level the playing field: