The Expert Sleepers ESX-8GT Mk3 is an 8-output digital gate expander designed for Expert Sleepers controller modules, including the ES-4, ES-40, and ES-5. It converts digital controller channels into sample-accurate gates, triggers, clocks, and logic signals for Eurorack systems.

The ESX-8GT Mk3 expands the utility of Expert Sleepers master interfaces by converting 8-bit digital CV data streams into eight discrete +5V digital outputs. Driven directly from host audio interfaces via S/PDIF or ADAT connections when paired with Expert Sleepers Silent Way software, the module achieves sample-accurate timing that avoids typical USB-MIDI jitter. Multiple expanders can be chained—attaching up to five ESX-8GT units to a single ES-4 host—to create an expansive matrix of up to 40 independent gate outputs driven by a single S/PDIF audio channel.

The Mk3 hardware revision updates the interface with backlit, illuminated 3.5mm jack sockets that provide real-time visual feedback for trigger activity on each output. Power is supplied directly via the host module's expansion header, utilizing +12V rail current strictly to illuminate the jack LEDs when active.