Old phones as streaming sources


   I'm curious how many  of you have converted old phones to streamers. I have found  that when I remove the sim card and shut off blue tooth and wire the phone to a dac with an appropriate USB adapter cable, my old iphone 6s makes a pretty good streamer. Just wondering what others experiance has been. It is a really economical way to source digital to a 2nd or 3rd system. You can even cut electronic noise further by running on battery power when listening and shutting off the screen once the music is rolling. Going one step further would be to transfer local files to the phones memory and turn off wireless altogether. I have not done this but theoretically it should help. I usually just run the Qobuz app and stream from that to my Chord Mojo. What's your experiance?

 

Ag insider logo xs@2xbruce19

@tubeguy76 

Ok, sorry about that.  But if you read the Archimago stuff, or if you look at the HiFi News reviews with measurements, the point is not that every streamer measures the same, or will sound the same.  What they demonstrate is that with some DACs, any differences with stream can be almost completely eliminated.  So it might be helpful if you gave a little more info on your experience.

Software based DACs in smartphones will always be inferior, but better than nothing in a house system, decent for headphones and for streaming in the car.

@lanx0003 Your question is a good one and the bottom line is I don't know how to answer it with confidence. This is one of the more pertinent statements I found.

To measure jitter need put pure sine to the input of a known system. At the system output, we check artifacts (harmonics) and noise. Jitter products (artifacts and noise) depends on the input signal. To check the dependency we can take a spectrum analysis of different input signal level and frequencies.Dec 29, 2017
 

What Is Jitter in Audio? - Headfonics

Apparently there are multiple ways to measure jitter and display it, sometimes across the audio spectrum and sometimes as a single number. I opted for the audio spectrum displays because they were available from both sources. Perhaps someone with deeper knowledge will help us out with a clearer explanation of how to compare the two.

I have an iPhone 7 still and use it to stream to high quality headphones and ear monitors via similar good quality headphone amps. The sound is as detailed and articulate as I have heard. YMMV but clearly on the grand scale of things audiophile level results can be had from older IPhone using the right external gear, which need not even cost a fortune. But you do have to do your homework and choose wisely which means do not limit your sources to sites that specialize in high end gear because those will totally overlook the very affordable diamonds in the rough out there for this kind of thing. Do not under estimate the capabilities and value proposition of the latest digital technology! You might be very pleasantly surprised.

@lanx0003 Invested a bit more time and watched this 25 minute video with citations about the nature and measurement of jitter.

Leads me to believe it is not that big of an issue. Which, taken with the info discussed above casts some real doubt in my mind about how important the streamer is relative to the dac.

In other words it does not appear to me that there are strong technical reasons that a modest streamer such as a phone can't produce good audio if run through a quality dac...and that is what my ears have been telling me. Now in the interest of full disclosure and fairness I am 71 and have tested my hearing and know it it, at best extends to 11 khz. Amir points out that perception of jitter is most easily perceived in the frequencies closer to 20 khz. So maybe younger listeners could be more sensitive.