Yamaha O2R mixer 2TR Tape Stereo RCA in/analog board tested/working see pix/demo
This is the board that slots into the "2tr In" section on the back of the o2r. has 2 1/4" jacks and 2 rca jacks. Each of these boards are held in a cage and screwed into the back panel. Here is a demo video of the o2r which also has a close up of the display.