Hi All, I recently had an old FurmanPQ6 parametric modded from unbalanced to balanced. When I attempt to use it via a channel insert, I can see signal getting to the unit via the overload LED at the input level pot, but I can't get return signal to the channel. If I return signal to another channel by way of individual patch cords rather than send/return type, I get signal, but not much. The schematic shows it to be a differential input, ground to pin 1, neg to pin2 and pos to pin 3 on input. Lines 2&3 in turn feed a TLO 76 opamp. Any help much appreciated.