mhedges
Super Member
Which iPhone do you have? If it is the one with the lightning port, as was mentioned above, you need the USB3 to lightning connector that will give you a USB input and a lightning input. You use the lighting input to power the phone and the USB input for the DAC.
The other option, if you don't want to have your phone docked all the time, is to use Airplay. Apple sells the Airport Express or you can buy third party knock offs. You need decent wifi to go this route, though. It is limited to 16/44.1 output, but it is bit perfect with CD quality and will transcode to 16/44.1 on the fly if you send it a different resolution. The upside to this method over Chromecast Audio is that it works with pretty much any app on your phone, where the Chromecast works with a handful of apps. The Chromecast Audio will play hi rez. Both options use wifi and optical output to a DAC or they will also send out analog audio.
If I was suggesting a combo unit of DAC/Amp/Airplay/Bluetooth/DLNA/Internet Radio, I would suggest the Yamaha WXC-50 (~$350). It also has a digital input, so you can plug in a Chromecast Audio ouput if you need to.
That looks like a neat unit.
You can also get a fully fledged network surround receiver for the same price. They will have built in apps for Spotify, Pandora, and maybe Tidal (not sure) and airplay support.
I'm honestly not a fan of using your phone as the source because it ties up the device, you have to worry about battery life, and there are still occasional problems with music streams stopping when the device locks etc. And Airplay can be pretty nice but it is very hard on your wifi network since the signal bounces around a lot.
For what it's worth I have had much better experiences with Airplay enabled receivers than with Airplay via Airport express. I never was able to get the Airport express to reliably stream without dropouts.