Ive run into that exact situation while wiring up a Rolls mixer into a larger PA system. Videos are great for showing the big picture, like how to connect this output to that input, but they usually skip over the smaller but important details. For me, the real lifesaver has been detailed manuals, because they break down signal flow and include those wiring diagrams that show exactly whats happening under the hood. When I had an issue with feedback, I went to the manual first and spotted a grounding tip that solved it. If youre looking for that level of clarity, the manuals at https://manuals.online/rolls are worth bookmarking. Theyve saved me from a lot of head scratching.