Today, iPad, iPhone and most Android apps are built to impose an external power usage cap. When you want to connect DAC to the iPhone, you need a self-powered DAC such as a C5D.
You can conveniently attach the computer to the DAC, because the DAC just draws power out of the tank.
It is also possible to connect a DAC without a battery. Most USB devices report their power consumption in software while a USB connection occurs. It is quick to trick a phone or laptop by attaching to a tiny USB hub.
If you use the right USB port, the phone reads just the same low power usage and the DAC does not absorb additional electricity.
For example, if you connect the DAC directly to the Android device, it will not work. All because the DAC absorbs at least 20ma.
The Android app enables up to 5ma of full power usage when a portable USB hub is attached. Other than this, the power consumption of the non-powered USB hub has not increased, but the DAC also draws power from the Android phone.
Android phone support for the digital audio system continues to improve sound quality. At the same time, only a few Android devices allow digital audio. Nearly all Android devices will link to the DAC with a USB audio file.
Other than Cyanogen Mod, it is known to enable the streaming of digital audio systems as well as applications with most smartphone devices.
Here you need to note that the proper cable and support on the device is required to connect iPhone to a DAC.
Throughout any scenario, you need to make sure any your DAC is powered on and attached to your Android computer, and then reboot it. It will give your device a chance to initialize the DAC.
Requirements for cables
You should not try attaching regular USB cables to an iOS box, and Android apps are not compliant with attaching to a DAC unit.
In that case, you will need a special cable that treats the DAC device as a client and the Android or iOS device as a host.
If you want to connect to an iOS device, use an approved Apple MFI or a genuine USB camera adapter cable. However, in the case of Android, you are going to need a good quality OTG cable or a brand.