Bohumin by XAOC Devices is an expansion module for the four-channel mixer Ostrawa. Primarily, the expander complements Ostrawa with a second full-fledged Stereo aux send/return path for optimal integration of Stereo effect modules. In addition, Bohumin allows level control of both return signals. The Active 1-4 connectors are gate inputs for (un)muting the channels via Gate voltage. The Aux B CV 1-4 inputs are used to animate the B Aux Send controls (i.e. those of Bohumin itself) via control voltage. Imagine feeding channels 2 and 4 with a Shimmer Reverb every eight bars via synchronized LFO. A dream for complex mixing techniques!