Expert Sleepers ES-9
While getting deeper into modular I realized I needed to better integrate it into my computer workflow, that’s where the Expert Sleepers ES-9 came in.
The ES-9 is a Eurorack 16-in/16-out USB audio interface, with DC-coupled inputs and outputs that can be used for both audio and CVs. With it’s balanced 1/4″ main outputs & headphone socket, it’s the perfect one-stop solution for integrating a modular synth and a laptop/tablet, either in the studio or when playing out at a gig.
Expert Sleepers
DC Coupling
The most import point above is the fact that it is DC coupled, most soundcards are AC coupled meaning that the soundcard will remove any DC offset in a signal. In most cases you would want this filtering to avoid any DC offset in your audio signal, I’ve previously shown some of the problems with DC offset. Filtering out DC offset is undesirable in CV signals as any kind of sustained value will be filtered out.
The Problem
While the module mostly worked as expected one frustration I ran into was in the default mapping there is no way to route audio through the module without involving a DAW. Despite wanting to further integrate the computer into my setup I still wanted to be able to use the modular when the computer was off. Within the ES-9 there is a concept of a hosted vs stand-alone mode but I was looking for something simpler.
Output Numbering
The ES-9 outputs are numbered in your operating system as follows. This will be important for setting up mappings in your DAW and the configuration tool.
| USB Out # | Hardware Out |
| 1/2 | Main Out |
| 1/2, 3/4 | Headphone Out |
| 5/6 | S/PDIF Out |
| 7/8 | ED-5 Out |
| 9-16 | Out 1-8 |
Configuration Tool
The ES-9 has a configuration tool in the form of a webpage that communicates with the ES-9 using MIDI. The version that matches your firmware can be accessed at https://www.expert-sleepers.co.uk/es9firmware.html. While the manual does cover the configuration tool it is still not fully clear so I will demonstrate my setup.
I have decided to use inputs 1-8 as DC Coupled Mono inputs. Inputs 9-14 I have set up as 3 AC coupled stereo pairs. Inputs 13/14 are set up to automatically output to the mains and headphones so that you can use the modular system even when not hooked to a DAW.
In order to achieve this I set the following settings in the config tool:
Bitwig Mapping
The final step is to map the inputs and outputs within your DAW, here are the mappings I use within Bitwig:
