The Fosi Audio S3 combines a digital transport, DAC and preamplifier in a single compact chassis. Its versatile design makes it suitable for wireless and network music streaming, as well as controlling home audio systems built around active speakers or a separate amplifier.

The architecture combines the Amlogic A113X platform, an AKM AK4493SEQ DAC and OPA1612 operational amplifiers for clean, detailed sound. The DAC supports PCM signal processing up to 32-bit/384kHz, with THD+N of no more than 0.00018% and a signal-to-noise ratio of at least 120dB.

The Fosi Audio S3 supports Spotify Connect, TIDAL Connect, Google Cast, AirPlay 2 and DLNA. Music can be sent directly to the network streamer from compatible music apps, allowing convenient playback control from a smartphone or another supported device.

In addition to online music services, music libraries stored on a network-attached storage device, or NAS, are also easily accessible. Broad protocol support allows the S3 to work with a variety of sources and home network environments.

The S3 can handle lossless PCM audio up to 32-bit/768kHz, combining the convenience of wireless control with sound quality comparable to wired systems.

The supported sampling rate depends on the selected input and transmission method. Optical and HDMI connections support up to 24-bit/192kHz, WiFi supports 24-bit/192kHz, Google Cast supports 24-bit/96kHz, and AirPlay 2 supports 16-bit/48kHz PCM audio.

The S3 features isolated analog and digital circuitry, Japanese ELNA capacitors and an ultra-low-noise LDO power supply. Its carefully designed internal architecture delivers clean and stable signal processing.

Dual operational amplifier differential amplification is paired with balanced XLR outputs. The design delivers greater channel separation and a wider soundstage.

Available from Google Play and the App Store, the Fosi Audio app provides easy setup and convenient playback control. Qobuz Connect setup is accessible through the app, simplifying the use of the compatible music service.

The built-in 10-band equalizer allows the sound to be tailored to personal preferences, the speakers or the listening environment. Playback and audio settings can be controlled from a single, intuitive interface.

The HDMI eARC connection allows audio from a compatible television to be sent to the S3. In addition to music listening, the unit can therefore serve as the central controller of an audio system for television and movie content.

An active subwoofer can be connected to the dedicated SUB OUT, allowing the S3 to form the heart of an immersive 2.1-channel home audio or home theater system.

Dual-band WiFi 6 supports both 2.4GHz and 5GHz networks, providing wide coverage and fast wireless data transmission. A 10/100Mbps Ethernet port is also available for a stable wired network connection.

Bluetooth 5.3 connectivity supports A2DP, AVRCP and BTLE, as well as SBC and AAC codecs. When using Bluetooth, the supported PCM sampling rate is up to 24-bit/48kHz.

The included Bluetooth remote control provides convenient operation of the S3 from a range of more than 15 meters. Thanks to Bluetooth connectivity, operation does not require a direct line of sight between the remote control and the unit.

App control and the Bluetooth remote provide flexible operation, whether you prefer controlling the network streamer from a mobile device or with a conventional handheld remote.

The S3 protects the unit and connected system with overcurrent and overvoltage safeguards. Bottom heat dissipation helps release the heat generated during operation, while the 12V trigger enables synchronized power control with compatible devices.

The compact 173 × 173 × 47mm chassis takes up minimal space, making it easy to accommodate in desktop and living-room Hi-Fi systems. Its compact dimensions make it an ideal companion for a separate integrated amplifier or active speakers.

The S3 has not yet completed the Roon Ready certification process, so native Roon Ready support is not currently available.

Playback from Roon is nevertheless available through AirPlay 2 or Google Cast. AirPlay 2 supports PCM transmission up to 16-bit/48kHz, while Google Cast supports up to 24-bit/96kHz.