It will work as expected if the XLR output from your preamp has active signal on both Pin 2 and Pin 3 of the XLR connectors. (Not all balanced outputs have active signal on Pin 3, but I believe the DEQX does.) Also, the two power amplifier output channels need a common electrical connection between the two black posts. Dave. Stereo balanced inputs with -10dB, 0dB, & +4dB (selectable level setting) - The stereo XLR inputs are suitable for high quality 2 channel input analog input source material. Typically this would be the outputs of your CD player, digital workstation master output pair, or any other stereo analog source.
I have made a kit where the output is unbalanced and designed for a simple mono 1/4 jack (2 leads). Could I just use this circuit and replace "capsule" with my output leads ? If not, could someone point me to a circuit with electret mic + simple preamp with balanced (XLR plug) output ? Hope this is the right board, thanks.