is there any way of making one output sound on both sides of my headphone? Since the headphone output can only play both channels simultenously, I’m listening through channel 1 in the hopes that I can preview the music I’m recording with a looper before I send it to the PA through channel 2. If there is any other way of being able to this I’d be grateful for tips.

you can use some specific cables that split stereo signal into 2 jacks, and then connect the headphone into only one of them