dbx ZonePRO 641 6x4 Multi Effect Processor 6 total inputs: four switchable Europort mic/line inputs, two unbalanced, mono-summed RCA source input pairs 4 outputs: four electronically balanced, RF filtered Euroblock outputs Frequency response: 20Hz - 20Khz, +/- 0.5dB 6 mic preamps with 15V phantom power 29W power consumption