The ES-40 is a Eurorack format module which converts a standard S/PDIF input to five channels of expansion headers, which are used in conjunction with the Expert Sleepers ESX range of expanders (currently including the ESX-8GT, the ESX-4CV, the ESX-8CV and the ESX-8MD). The ES-40 will connect to any audio device using the S/PDIF standard. This includes the digital audio output provided as standard on many recent Macs (more info here on the Mac connection). The ES-40 also includes an S/PDIF output for sending data back to the computer. This output is used by expansion modules connected to the ES-40; currenty, the only such module is the ES-7 CV Input Expander. The ES-40 is essentially an ES-4 with the DACs and CV outputs removed. Much of what has been written about the ES-4, and many tutorial videos etc., still apply to the ES-40. Brand new with warranty. Video: https://youtu.be/deU2gBk_T74Product Specs Item Number: 10285 Make: Expert Sleepers Model: ES-40 Condition: Brand New Finish: Black Categories: keyboards-and-synths ⇒ eurorack Function: Clock Generator Controller CV Modulation MIDI Utility Made In: United Kingdom MPN: 160714300204023 Modular Grid: Eurorack ⓘ + Dimensions*: 6 HP 51 mm deep Power*: 26 mA +12V 0 mA -12V 0 mA 5V * User contributed details