The Digiface USB is an extremely compact & portable digital audio interface with 4 optical ADAT / SPDIF I/Os, and an analog high-quality line/phones output via 6.3 mm TRS jack. Continuing the legacy of RME‘s famous HDSP Digiface, a triple ADAT I/O interface with phones and PCI interface, Digiface USB simplifies connection with USB 2, does not need an external power supply, and even adds another optical I/O, resulting in 32 channels input and output each when using ADAT optical. The analog output hosts channels 33/34, and can be used freely thanks to TotalMix FX, RME‘s routing and monitoring solution that knows nearly no limits in routing and mixing (the Digiface USB does not include FX). Each single optical port can use either ADAT (up to 8 channels) or SPDIF (stereo). While the inputs adapt automatically to the received signal format, the outputs can be individually switched between ADAT and SPDIF operation. Supported are SMUX and SMUX4. Therefore at 192 kHz either 8 channels via 4 x SPDIF or ADAT are possible on both inputs and outputs. Its small size, weight and bus-powered operation make the Digiface USB extremely versatile and useful. It could even serve as simple headphone amp for mobile use.