I am using poly with 8 voices. At some point, I need to use the sum of all 8 voices and feed it into a single voice, and create a feedback from all 8 voices to 1. But I'm not clear on the way to do that. Should I get the signal from the outlet of poly~ and feed it back down to that deep deep patcher? Or is there any way to get the sum of signals in the poly patcher? Any suggestions?