The NUX MLD Bass Preamp + DI is a bass guitar preamp, DI box, impulse response (IR) loader and audio interface in a single pedal. NUX collaborated with American bass player Melvin Lee Davis to create it, and NUX describes it on its artist page as his signature bass preamp and DI12. For a bass player it covers the ground of several boxes at once: tone shaping before the amp, a balanced feed to the desk, cabinet simulation for going direct, and USB audio for recording at home. It sits in the wider field of preamp pedals and bass pedals.
What it does to your sound
NUX lists the pedal's sound-shaping controls as a 3-band EQ with middle-frequency selection, drive with blend control, speaker cabinet simulation through the IR loader, and built-in noise reduction with Decay and Threshold controls1. The blend control on the drive lets you mix processed and clean signal, and the mid-frequency selection gives control over where the middle band sits rather than only how much of it you hear. The noise reduction with its own Decay and Threshold controls is aimed at keeping high-gain and drive settings quiet on bass, where hum and handling noise show up quickly.
The volume knob adjusts the overall output volume of the pedal. NUX describes it as ideal for fine-tuning the output on clean tone, and notes that it also controls the DI output volume1.
Outputs and recording
The pedal's DI output is a balanced XLR output carrying a mic-level signal. A Pre-Post switch sets whether that signal is affected or unaffected by the pedal's processing, so the desk can receive either your full shaped tone or the raw bass signal1.
As a USB audio interface it offers three routing options for streaming1:
- NORMAL: you create your tone using the pedal, and it sends the processed signal.
- DRY OUT: no preamp effect or IR simulation, for re-amping later.
- REAMP: play back a recorded track and process it while recording to a new track.
There is also a 1/8-inch (3.5mm) auxiliary input to connect a music player, and a headphones output for silent practicing1.
Firmware
NUX offers MLD Firmware V4.0 for the pedal, with downloads for both macOS and Windows1.
Videos
MyMusicMasterclass
Tom PlaysRhythms
Band On A Budget
Questions
Who designed the NUX MLD Bass Preamp + DI?
NUX collaborated with American bass player Melvin Lee Davis to create the pedal, which carries his initials in its name. NUX describes it as his signature bass preamp and DI, built around the sound-shaping controls and cabinet simulation he wanted for bass.
Can the NUX MLD Bass Preamp + DI be used as an audio interface?
Yes. NUX lists it as an audio interface alongside its preamp, DI and IR loader roles. It streams USB audio with three routing options: NORMAL sends the processed signal, DRY OUT sends the signal with no preamp effect or IR simulation for re-amping, and REAMP plays back a recorded track while you process it and record to a new track.
Does the NUX MLD Bass Preamp + DI have an XLR output?
Yes. It has a balanced XLR output carrying a mic-level signal. A Pre-Post switch sets whether that DI output is affected or unaffected by the pedal's processing, so you can send either your shaped tone or the raw bass to the desk.
Does the NUX MLD Bass Preamp + DI have cabinet simulation?
Yes. Speaker cabinet simulation is one of its core features, handled through an impulse response (IR) loader. NUX lists it among the pedal's sound-shaping controls alongside the 3-band EQ, drive with blend control and built-in noise reduction.
Is there firmware for the NUX MLD Bass Preamp + DI?
Yes. NUX offers MLD Firmware V4.0 as a download for both macOS and Windows, so the pedal's software can be updated on either platform.
Sources (2)
- MLD Bass Preamp + DI, NUX Audio, 2025-08-21
- Melvin Lee Davis, NUX Audio
