Silver Supporting Member
What are the two 1/4'' plugs for, next to the speaker jack?
This probably doesn't help, but mine has two speaker outputs, which are in the same position as the two unidentified jacks on yours. It doesn't have a speaker output where your main one is.
Personally I think you should ask Tony Bruno - IMO it is unacceptable to have unlabelled jacks on an expensive amp like a Bruno.