OB-XOne mkII - Oberhim OBX Expander Module in Custom Rack

video upload by Lackan

"My first version of the OBXone went on to save an Original 4VS OBX. But when I got a Rosen motherboard as part of a trade I thought I'd make a nicer one, 2U rackmount, with double sub oscillators and all the extras."

Looks like an SEM in rack form, but appears to be based an OBX voice board according to the description above. The OB-X filter is based on the 12db Lowpass disctrete SEM filter (it's missing the variable LP -> Notch -> HP knob), while the OB-Xa switched to Curtis based filters.

Also see SUB Oscillator for the Oberheim SEM Module