Direct-to-DAC, Bit-Perfect USB Music Player for Android
Bypasses Android's audio framework to stream bit-perfect PCM straight to external USB DACs.
💡 Looking for the macOS desktop version?
We keep each platform in its own dedicated branch. Switch to themacosbranch or run:
git clone -b macos --single-branch https://github.com/yukaatsu/tsrossa.git tsrossa-mac
If you plug a USB DAC or dongle into Android, the operating system routes all audio through AudioTrack and AudioFlinger. Even if your file is 44.1 kHz, 96 kHz, or 192 kHz, Android forces it through a software resampler (SRC) to a fixed 48 kHz, runs it through internal digital volume attenuation, and adds latency.
tsrossa bypasses the Android audio stack entirely.
It asks Android only for the raw USB permission (usbfs file descriptor). From that moment on, a native C++17 engine talks directly to your DAC via libusb, tells the physical DAC clock which crystal oscillator frequency to switch to, pre-loads the audio into RAM with POSIX mlock(), and sends the raw PCM stream over USB Isochronous endpoints.
What's in your file is bit-for-bit what reaches your DAC's converter chip. No resampling, no mixer, no OS interference.
Now Playing Adaptive album art theme, smooth scrubber, tactile header controls, and synchronized lyrics |
Library Browser Fast cached browser with live search, folder picking, intelligent filename parsing, and 11 sort modes |
Hardware Telemetry Live UAC endpoint audit, clock verification, RAM buffer stats, and 1-tap diagnostic report export |
- Direct Kernel-Level USB Audio (
usbfs+libusb-1.0)
ZeroAudioTrack, zeroAudioFlinger. The C++17 engine manages asynchronous USB Isochronous transfers directly. - Physical Clock Switching (UAC1 & UAC2)
Reads your DAC's USB descriptors to configure the hardware oscillator viaCS_SAMPLING_FREQ_CONTROL. A 44.1 kHz track plays at 44.1 kHz; a 192 kHz track plays at 192 kHz. - RAM Pre-Caching with Memory Pinning (
mlock)
Decodes audio files into a linear PCM buffer in RAM and locks the pages so the Linux kernel never swaps them to flash storage, eliminating micro-stutters. - Dual Volume Architecture
- Hardware UAC Mode: Controls the DAC's internal volume registers via
FU_VOLUME_CONTROL. At 100%, it engages bit-perfect True Unity Gain (0.0 dBFS). - 64-bit Studio-Taper DSP: Calibrated logarithmic curve with decorrelated SplitMix64 TPDF dither and mid-tread quantization (
std::llrint) for DACs without hardware mixers.
- Hardware UAC Mode: Controls the DAC's internal volume registers via
- Gapless Playback
Background worker decodes the upcoming track into a secondary RAM buffer and seamlessly hands over USB packets across track boundaries without pops or gaps. - Modern Material 3 Interface
Built with Jetpack Compose. Dynamic color palettes extracted from album artwork, clean typography, synchronized.lrclyrics, fast alphabet scroller, and a dedicated DAP (Screen Pinning) mode to turn older phones into dedicated audio transports.
| Category | Details |
|---|---|
| Supported Formats | • FLAC (.flac): 16-bit, 24-bit, 32-bit PCM (44.1 kHz up to 384 kHz)• WAV ( .wav, .wave): 16-bit, 24-bit, 32-bit Linear PCM, and 32-bit IEEE Float |
| Target Hardware | Any USB DAC connected via USB-C OTG (Dongle DACs, portable DAC/amps, desktop DACs) |
| USB Class | USB Audio Class 1.0 (UAC1) & USB Audio Class 2.0 (UAC2) |
| Transfer Type | Asynchronous and Adaptive Isochronous USB endpoints |
| Android Version | Android 8.0 (Oreo / API 26) through Android 15+ (API 35+) |
Note on Scope: tsrossa is intentionally focused on bit-perfect offline playback for external USB DACs. Lossy formats (MP3, AAC) and internal phone speakers / Bluetooth are bypassed to keep the native audio pipeline clean and jitter-free.
Grab the latest release .apk from the Releases page and install it on your Android device.
- Plug your USB DAC into your phone using an OTG cable or USB-C interconnect.
- When Android shows the "Allow tsrossa to access [Your DAC]?" prompt, check Always allow and tap OK.
- Pick a track from your library and enjoy bit-perfect playback.
Tap the [LOGS] button in the top header to inspect:
- Real-time negotiated sample rate & bit depth
- Active USB endpoint addresses and buffer latency
- Bit-perfect transmission verification
- One-tap button to copy or share the diagnostic log for troubleshooting
If you prefer building tsrossa yourself:
- JDK 17 (e.g. OpenJDK 17)
- Android SDK (
compileSdk = 34,minSdk = 26) - Android NDK (r25+ /
25.1.8937393or newer) - CMake 3.22.1+
Make sure your local.properties points to your Android SDK:
sdk.dir=/path/to/your/Android/sdk# Clean build
./gradlew clean
# Build debug APK
./gradlew assembleDebug
# Build release APK
./gradlew assembleRelease
# Output: app/build/outputs/apk/release/app-release.apk
# Run unit tests
./gradlew testtsrossa is an independent open-source project. If it brings your music to life or gives your portable setup new clarity, support is warmly appreciated:
Found a bug or have DAC compatibility data? Feel free to open an issue on GitHub Issues with your hardware log report attached!
tsrossa is licensed under the Apache License 2.0.