Designed to plug in between your axe and amp, the Fishman Pro-EQ Bass Preamp provides feedback control, photo-optic compression, 5 bands of EQ, and XLR direct out with ground lift, and tuner/send output. 3 midrange bands plus bass and treble are optimized for the electric or upright bass and easily dial out runaway frequencies. The bass slider"s range is 30-275Hz which lets you precisely tweak G-string tone. Feedback can also be controlled with Depth and Phase switches. Ergonomically shaped with rubber feet to keep the unit from wandering. Operates on 9V battery or optional AC adapter.Outputs: Main, XLR main, Tuner/Send 5-band EQ Depth control Compressor