Is this equipment, (the unbalanced equipment) at +4db level, or -10db level? The Balanced equipment may auto unbalance, by sensing the type of connector (TRS), or 1/4 Phone. If the balanced connections are XLR, then different wireing on the XLR connector end may be required. If the equipment is -10, like an older Tascam board, there is an interface that will handle the conversion of -10 to balanced +4db, for both inputs and outputs, up to 8 channels per unit.
This product is EB TECH level shifter, and can be seen at
type in ebtech in the search box, also if you are going to work something out on your own, then
hope this helps,