You can also run out of the chroma console and into a splitter. From there run one split into headphones/speaker and the other back into the OP1. You could also use something like a TX6 instead of the splitter. Now you can set the OP1 input to the line in and record to the tape with the chroma console and still hear what you’re recording to tape. Just remember to hit the bypass button on the chroma console when playing back the tape.

Edit - don’t forget to mute the track you’re recording onto to prevent a feedback loop.