The Expert Sleepers ESX-4CV adds four CV outputs to their ES-4 or ES-5 modules. Each of the module’s channels are time multiplexed, meaning they run at 1/8 of whatever the sample rate is. While this is fine for processing CV signals, it does not work with audio or extremely fast envelope signals. However, unlike many MIDI interfaces, the module provides extremely accurate timing and the complete elimination of jitter.
The ESX-4CV requires software in order to time-multiplex the four output signals, and to encode them for the ES-4 or ES-5. Currently, the only such software is the 'ESX-4CV Combiner' plug-in, part of Expert Sleepers Silent Way.
Silent Way is available in AudioUnit and VST formats for Mac OS X and Windows. Use of Silent Way therefore requires a compatible host application (DAW). For Pro Tools users, Silent Way is known to work with the FXpansion VST-RTAS wrapper.
A Silent Way licence is not included with the ESX-4CV - however, the ESX-4CV Combiner plug-in functions in a licence-free mode, so ESX-4CV users are not forced to buy Silent Way. Such users can than evaluate the rest of the Silent Way suite in demo mode.