Oakley Sound Four-Way Midi-CV Converter
I rarely use more than one of these at any given time, though if I only had a single one, it would have to have a front panel MIDI channel select switch. This is useful when creating strummed guitar parts in Cubase. The strummed chords can have each note assigned to a different MIDI channel in the MIDI track, then the appropriate channel can be selected on the MidiDac to split the part for recording each note of the chord separately in time.
This is in an actual rack case and the power supply is taken to chocolate block connectors on the back which supply some of the other panels.