Can I use this on the output 3 jack ? Instead use the XLR outputs ? Thanks.
I don’t see why not. Being passive (transformer based) it may alter your tone slightly but should work fine. Are you wanting to be able to take a ballanced and unballanced output from output 3?
if you wanna use output 3 or 4 as balanced outputs, you just need a 1/4" TRS to XLR cable and you’re good to go. The 3 & 4 outputs are already balanced outputs.