first you have an old iPad, you install, Music, Qoboy, Tido, spota, or whatever please you, I also like Amazon, for HiRez.
you install and start to stream, but you have to buy this Gizmo
You use lightning for Charging and USB 2 cable to the DAC, for music
Since it is an old iPad, no need to unplug or unplug at night to preserve battery.
You have to choose audio-quality : Wifi Streaming/Hi-Res lossless/HiRez lossless[Alac up to 24/192kHz]
Since streaming goes out of the iPad [no usual compression from AirPlay, the iPad play direct], it is respecting the format you are listening, so no conversion HiRez is HiRez and Red Book is Red Book, you have to choose HiRez lossless in the gear and iPad manage the rest.
here my Fiio F11 R2R, that gave me the resolution number for verification
Sometime you have to reboot the iPad, the first time you setup, to make it work, depending of the OS it have!
than if you want to control it with your iPhone, you go accessibility
you choose control nearby devices (clic to choose and click again to see the menu)
[Bluetooth must be on]
There you should see you iPad name, clic on it
and there plenty of fonction there you could control, i will let you discover, but for controlling the music playing you have to choose the circle with 3 dot, than scroll down to media, where you will see:
play/pause
previous
next
volume up
volume down
that’s full HiRez and remote control with iPhone.
sorry for Android, i don’t know
extract from Help_Wire:
The easiest way to control an iPad remotely is by using the Control Nearby Devices feature. This option allows you to manage basic functions on an iPad from a nearby iPhone. While it doesn’t enable app interaction, it lets you return to the Home screen, view (but not use) the App Switcher, access the Control or Notification Center, and control media playback—adjusting volume, skipping tracks, or pausing. Beyond media control, it’s also useful for silencing alarms or quickly exiting apps by returning to the Home screen.
How to Control an iPad Remotely from an iPhone, Mac or PC
This is a very affordable solution for HiRez music!
it work with old iPhone, but it is unstable and lot of reboot


