USB
I plugged my phone (S8) running Android 8.0.0 into the USB of my Benchmark DAC 1.
I used a USB-C > A cable connected with a USB A-A adapter to a USB A > B cable.
It didn't work.
Using a Samsung supplied adapter (USB C to A) and an A to B cable, it worked.
The Benchmark DAC 1 is a UAC1 device.
This means the USB audio is limited to 24 bits / 96 kHz max.
Started Foobar mobile and without any adjustment or configuring the DAC started to play.
In Foobar I activated the re-sampler and set it to 96 kHz, the highest available rate.
Music kept on playing.
It look likes Android 8 support 24 bit / 96 kHz audio.
Host mode
Android 5.0 (API level 21) and above supports a subset of USB audio class 1 (UAC1) features:
- The Android device must act as host
- The audio format must be PCM (interface type I)
- The bit depth must be 16-bits, 24-bits, or 32-bits where 24 bits of useful audio data are left-justified within the most significant bits of the 32-bit word
- The sample rate must be either 48, 44.1, 32, 24, 22.05, 16, 12, 11.025, or 8 kHz
- The channel count must be 1 (mono) or 2 (stereo)
Host mode is USB audio as we know it when connectiing the DAC to a PC.
The PC (or in this case the phone) is the host.
Powering the DAC might be a problem.
This can be solved by using a powered hub.
Old Android devices have a micro-USB connector that does not permit host operation, an on-the-go (OTG) cable is required.
USB Audio Tester
A little app by Daniel Sobe available on APK.center
You need to root your device first.
Below is an older version, runs without rooting.
Select the USB device, in this example my Benchmark DAC 1 USB
All the sample rates supported by the USB receiver of the DAC are listed.
- USB audio - Android Open Source Project
- PulseAudio vs. AudioFlinger - Arun Raghavan
- Making Fiio Q1 Mark II DAC working with Samsung Galaxy S8 - Head-fi 2018