A bass guitar preamp, DI box, impulse response (IR) loader and audio interface for practicing, gigging and recording is in one Closer Look NBP-5 Bass Preamp + DI features fully sweepable mid-range frequencies in addition to Bass and Treble controls. Melvin L. Davis is proficient at 4, 5, 6 and 7 string basses, so, MLD Bass Preamp has a wide range of frequency control. Volume Knob Adjusts the overall output volume of the pedal. Ideal for fine-tuning the output on clean tone, it also controls the DI output volume. Blend Knob Adjusts to blend between the clean signal and overdrive signal. The clean signal remains as unity gain, allowing for fine control of the blend ration. Drive Knob Adjusts the Gain level and sets the saturation level in the overdriven signal. 3-Band Equalizer with Middle Frequency Selector Bass : +/- 12dB @40Hz Middle : +/- 17dB @160Hz to 1000Hz Freq. : 160Hz ~ 1000Hz Treble : +/- 12dB @8000Hz Read more DI Output Balanced XLR Output carrying the mic- level output signal, either affected or unaffected depending on the Pre-Post switch. GND LFT (Ground / Lift) Toggle Switch Disconnects the signal ground on the DI out to break any ground loops. Toggle the switch to the LESS noisy position; it can be either GND or LFT depending on the room, stage or studio condition. Switch does not effect the 1/4-inch (6.5mm) output. Impulse Response (IR) Toggle Switches You can activate/deactivate the IR cabinet simulation for both DI out and 1/4-inch (6.5mm) out separately. Use the appropriate IR toggle switch to turn ON/OFF the emulation for the output you choose. Input/Output and USB Connections Main OUT and Through You can use the main "OUT" and "THROUGH" output to get the dry signal for bass amplifier connection. When you activate the "OUT IR" cabinet simulation, you can connect the pedal to any FRFR speaker, directly to a mixer or audio interface. "THROUGH" output will remain bypassed either the "OUT IR" is activated or deactivated. DI Out, Auxiliary Input and Headphone Output On the LEFT SIDE of the PEDAL, you can access the XLR output for a mixer and/or audio interface connection, and you have the option of activating the IR cabinet simulation.