The NUX MG-300 is a compact digital multi-effects unit and amp modeler from NUX, launched in July 2020 as a smaller modeling unit that takes cues from its predecessors such as the MG-1001. It packs 25 amp models and 50 effects into a floor unit with two footswitches and a built-in expression pedal, and its digital modeling runs on NUX's TSAC-HD pre-effects and amp modeling algorithm23. NUX describes the pre-effect block as recreating "the awesome signature sound of real analog overdrive / distortion pedals"2.
For a player, it is an all-in-one board substitute: amp, cab, drives, modulation, delay and reverb in one box, plus a USB connection that lets it work as an audio interface and load third-party impulse responses4. Guitar World placed it in a budget multi-effects roundup and found that "despite costing around $170, the MG-300 delivers some very satisfying sounds"3.
What it is and what it does
NUX positions the MG-300 as a "Compact Modeler"2, and Guitar.com reported at launch that its digital modeling works off the TSAC-HD algorithm1. The unit holds nine banks with four presets each, which Guitar World called "plenty of options for players who want to create their own playlist"3. The enclosure is plastic, which that same guide called rugged enough for home use but not as rugged as Boss or Line 6 options, something it said is to be expected at this price3.
The expression pedal
The MG-300's built-in expression pedal can be assigned to different jobs depending on which block you attach it to. NUX's product page lists a function for each block2:
| Assigned block | What the expression pedal controls |
|---|---|
| WAH | The WAH filter |
| AMP | The LEVEL parameter of the amp |
| EFX | GAIN (DRIVE) of OD/DIST, or PITCH of the PITCH BENDER |
| MOD | MIX level of modulation effects |
| DLY | MIX level of delay effects |
| RVB | MIX level of reverb effects |
That range covers the common real-time moves: volume swells on the amp level, wah sweeps, driving an overdrive harder with your foot, or blending delay and reverb in and out. The same approach appears across the NUX range: the MG-400 also has a built-in expression pedal with no external pedal required for wah, and the MG-30 can remote its signal blocks from an external expression pedal or the NUX NMP-2 LITE78.
Bass amps and cab IRs in the V4 firmware
The MG-300's V4 firmware (version 4.02.23) added tools for bass players and for singer-songwriters2:
- An MLD Bass Amp model, with a MIC input and an adjustable gain control for a dynamic microphone, which NUX pitches as "a perfect solution for the performing singer/songwriter"
- Three bass cabinet impulse responses, each based on a known cabinet:
- SV810, based on the Ampeg SV810 cabinet
- DB810, based on the Aguilar DB810 cabinet
- TRC410, based on the Trace Elliot 410 cabinet
With the mic input and gain control, one unit can process both a guitar and a vocal microphone, which is an unusual capability in a compact modeler at this price2.
What reviewers said
Guitar World's Matt McCracken, writing in the magazine's budget multi-effects guide, was positive overall6:
"I think the NUX MG-300 is a brilliant multi-effects pedal for the beginner guitarist6."
That same guide flagged one drawback: the editor software "isn't the easiest to navigate"6. A later Guitar World piece summed up its strengths as sounds, control and connectivity:
"the NUX MG-300 offers a plethora of sounds for you to utilize, as well as an expression pedal. It works as an audio interface, and you can even load third-party IRs."4
Guitar World, 20264
Versions and editions
The original MG-300 was a strong seller for NUX. At the 2025 NAMM show the company introduced an updated version, and on Premier Guitar's NAMM coverage NUX's Mike said of the original9:
"the mg300 was one of our best sellers like for the last four plus years"9
The updated MG-300 Mark II shipped at $169 and was available to start shipping right away9. NUX describes the MKII as a compact and portable amp modeler and multi-FX10. Its firmware line has continued: V2 firmware 2.0.0 arrived on 2026/04/14, and GEN2 firmware 3.0.0 followed10.
The China mainland exclusive version of the MG-300 ships without the collaboration patches found in other regions, according to NUX's product page2.
A Premier Guitar video from NAMM 2025 walks through the updated unit: NUX's Mike explains the overhauled DSP, the new USB-C port on the back, and the $169 price with immediate availability9.
Videos
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News
Questions
Can the NUX MG-300 be used as an audio interface?
Yes. Guitar World notes that the MG-300 works as an audio interface, so you can record straight into a computer over USB while using its amp and effects modeling. It also loads third-party impulse responses, which makes it usable as a compact recording front end.
Can you load third-party IRs into the NUX MG-300?
Yes. Guitar World's reviewer confirms the MG-300 can load third-party IRs (impulse responses), the speaker-cabinet capture files used for cab simulation. That lets you replace the stock cabinet sounds with your own captures or downloaded IR libraries.
Is the NUX MG-300 true bypass?
No. Guitar World lists its bypass as buffered, meaning a buffered signal passes through the unit's circuitry when the effects are off rather than being switched completely around it. This is common on digital multi-effects units.
How many presets does the NUX MG-300 hold?
It has nine banks with four presets each. Guitar World describes that as plenty of options for players who want to build their own setlists, and the presets are reachable from the unit's two footswitches.
Does the NUX MG-300 come with a power supply?
Yes. Guitar World lists its power as a 9V DC power adaptor included in the box, so you do not need to buy a separate supply to run it. It runs on 9V DC like most compact pedals.
What is the difference between the MG-300 and the MG-300 MKII?
The MKII, shown at NAMM 2025 and shipping at $169, has a completely overhauled DSP, a USB-C port on the back, TRRS live streaming, and a physical Toe Switch on the expression pedal that needs no calibration. Each IR on the MKII is adjustable with LEVEL, HIGH-CUT and LOW-CUT controls.
Sources (10)
- Nux launches the MG-300 Modelling Guitar Processor, Guitar.com, 2020-07-02
- MG-300 - NUX Audio, NUX Audio, 2026-04-08
- Best multi-effects pedals 2026: replace your rig, Guitar World (www.guitarworld.com), 2022-08-25
- Harley Benton DNAfx GiT multi-effects pedal review, Guitar World, 2025-05-31
- Boss GX-1 review, Guitar World, 2026-01-15
- Best budget multi-effects pedals: a world of effects, Guitar World, 2022-09-27
- MG-400 - NUX Audio, NUX Audio (nuxaudio.com), 2026-07-10
- MG-30 - NUX Audio, NUX Audio (nuxaudio.com), 2026-06-22
- NUX Amp Core Studio & Drive Core Deluxe MKII Demo, Premier Guitar, 2025-01-24
- MG-300 MKII, NUX Audio, 2026-08-05
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