So if I wanted to simulate +4 dBu level for the balanced connections, should I convert 1.228 Vrms to Vpk? That is 1.736 Vpk - which is what I need to use for my simulation?
The calculation looks correct, but the schematic doesn't. You have two 1.736 V peak sources that are effectively in series, so you get just over 10 dBu.
