Have you ever used the USB audio out on your Roland boutique? If so, is it possible to monitor that audio signal through your DAW/audio software using the boutique’s headphone out without also hearing the same audio coming from the boutique?
For example, if you route the USB audio through a reverb effect in your DAW (Reaper, Ableton, Logic, Amazing DAW-less DAW for DAWH8rz, etc.) and listen through the boutique’s headphones, do you hear the effected signal AND the signal from the boutique, or just the effected signal?
Thank you for humoring my crazy. 
