The Hifime S2 is an USB DAC with an additional optical (spdif) input. It's based on the Sabre DAC Chip ES9038q2m from ESS Technologies which is the latest generation of the mobile hifi DACs and succeeds the ES9023, ES9018k2m and ES9028q2m. It’s a very high-performance 32 Bit stereo DAC featuring the patented 32-bit HyperStream II DAC architecture and Time Domain Jitter Eliminator. It's more powerful with 49mW of output to 32 ohm and can drive most headphones and also line level loads (preamps and amplifiers).
We have constructed this DAC to use interchangable cables so that you can use it with any device without adaptors. The DAC has a microUSB female connector, and we have available cables to connect to:
Optical SP/DIF input
The optical input can be used with devices such as TV’s, Chromecast Audio, routers like Apple Airport express, CD players and many other devices. The optical input accepts all sample rates up to 192kHz/24 bit. When the optical input is used you need to connect power through the USB port with a microUSB cable. Power can be provided from any normal USB port, a USB charger or a dedicated USB power supply. It only needs 30-50mA.
The optical input uses 3.5mm connector. We can supply a cable with 3.5mm in one end and TOSLINK in the other. Additionally a TOSLINK to 3.5mm connector can be used in case your source device also uses 3.5mm connector and you’ll need 3.5mm in both ends.
There are 2 LED lights that indicates Power and Signal lock.
USB input accept all sample rates up to 96kHz and 24 bit and works without drivers on most computer system. Android devices works but Android support depends on the actual phone model and the Android OS software version. We have tweaked the settings on this version so that iPhones doesn't (incorrectly) believes that it requires too much power. We have also tested the different cables with many phones.
If both optical and usb is connected at the same time then optical input will take priority and USB is only used for power only.
Manual available here