Expert Sleepers ES-8 is a USB 2.0 class-compliant USB audio interface in a Eurorack module with DC coupled inputs and outputs that can be used for both CVs and audio. As such, it is compatible with all popular computer-based CV generating programs and audio/CV processing iOS apps. The ES-8 also has one ADAT input and one ADAT output each. These Toslink optical jacks can be used to add additional inputs and outputs to the module or to use a traditional audio interface such as mic preamps or 1/4" line outputs. An expansion header on the back of the module allows the connection of an ES-5 Expert Sleeper, to which Gate, CV and MIDI Expander can be connected.