Updated Sep. 9, 2022

NUX MG-400 Amp Modeler

Amp modelers in recent years have shrunk considerably in size, so much so that the race among competing builders is now not about how small you can make them, but how many features you can pack into them. In this optic, the NUX MG-400, with its gorgeous 2.8″ color display and stereo routing, fares pretty darn well, in particular considering its price.

An upgrade to the NUX MG-300, it features the same amp modeling algorithm emulating the behavior of analog circuitry, with a selection of 27 amp models (including one for bass and one for acoustic), 33 cabinet IRs (of which 8 are for bass) including 4 mics and 3 mic positioning variations.

Needless to say, Impulse Response technology is a big feature of the MG-400, offering 512 sample resolutions for each IR. You can also load 3rd party IR files using the NUX QuickTone software.

The effect section recreates the signature sound of all sorts of real analog pedals, whose position in the routing can be easily moved thanks to the intuitive graphic interface. There are plenty of stereo effects, by the way.

Just like the MG-300, it supports NUX Phrase Loop Synchronization with Rhythm, which is basically an automatic drum machine that will synch to your loops, but the 400 expands this feature with an extra recording mode:

NR = Normal Recording works as regular loop function, while you press CTRL1(LOOP) footswitch, it starts to record the phrase loop.

AR = Auto Recording will stand by while you press CTRL1(LOOP) footswitch, once you hit the strings, it will start to record your phrase loop.

It can also be used as an audio USB interface.

Another new (and interesting) feature is the Scene function. A scene is a slight variation on a preset, and each preset has 3 of them. This allows you to exclude/add blocks (like a single effect pedal, for example) without changing preset, by pressing the CTRL1 or CTRL2 footswitch. When disengaging signal blocks for reverb or delay, trails are retained.

Here are the videos. We added the NUX MG-400 to our article about the best amp modeler pedals.

NUX MG-400 Amp Modeler, Builder’s Notes

The NUX MG-400 is a value packed modeler akin to his little brother, the MG-300. MG-400 houses 2 powerful DSP chips for high-definition White-Box Amp Modeling algorithm (TS/AC-HD) and Core-Image post-effects. Since releasing the MG-300, people have been blown away by the sound and playability, not to mention the ease-of-use tone tweaking and intuitive interface. And now, the MG-400 builds upon the MG-300 feature set moveable signal blocks, 12 IR COLLECTION slots, flexible P.L block with MIN & MAX parameter setup, abundant SYSTEM MENU, and physical MASTER volume knob, MG-400 is now the best value modeler for the money.

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WHITE-BOX AMP MODELING

Same Amp Modeling Algorithm as MG-300, for easy Tone Tweaking:

The White-box Amp Modeling & Pre-Efx algorithm offers realistic playability and analog-chaos response.

The concept of “Chaos makes the muse” perfectly applies to the analogue circuit. When you tweak the knob, it affects itself as well as other parameters. For a linear digital system, the parameter is independent. The white-box algorithm offers real-time feedback, increment-by-increment. NUX TS/AC-HD replicates the same playability most guitarists crave in a real tube amplifier.

IMPULSE RESPONSE

512 samples IR resolution and USER slot with each patch. (additional 12 IR COLLECTION slots)
The MG-400 includes multiple impulse response of 512 samples each. You can load 3rd party IR files using our NUX QuickTone edit software (support up to 48kHz sample rate). The included 25 guitar cabinet IRs combine 4 classic microphones with 3 mic positions to allow beginners a quick and easy way to jump into the multi effects experience. Also included are 8 bass cabinet IRs and 3 acoustic guitar IRs, giving you the ability to play bass guitar on MG-400 or use electric guitar to simulate acoustic guitar sound with acoustic guitar IRs.
10 INDEPENDENT FLEXIBLE BLOCKS
NG, CMP, EFX, AMP, IR, EQ, MOD, DLY, RVB, P.L | 10 independent moveable signal blocks.
You can move signal blocks freely on the MG-400 and/or QuickTone editing software. Set the PATCH LEVEL block in front of AMP to swell the volume. Put DELAY block in front of gain stage to create grooving riffs. There are lots of tone creations with the flexible block routing.

2.8” COLOR LCD
2.8” 320*240 color LCD with intuitive UI.
An intuitive user interface with a colorful LCD lets you get rid of reading manuals. Keep it Simple!

SCENE FUNCTIONALITY

Use SCENES to engage/disengage blocks with either CTRL footswitch. You can assign CTRL1 or CTRL2 to trigger the SCENE Functionality. Each preset has 3 scenes, which are snapshots within a preset. This is a powerful function for live gigs. Each SCENE can engage/disengage signal blocks freely, and it retains the DELAY / REVERB trails when you disengage them with SCN CTRL.
Jam ( Drum & Looper )
The MG-400 supports NUX Phrase Loop Synchronization with Rhythm. You can play the rhythm then record your phrase loop. MG-400 will automatically beat match the phrase to fit the current rhythm BPM.
*Choose either STEREO / MONO looping. (Stereo is 30 seconds, mono is 60 seconds.)

Two Recording Modes
*NR = Normal Recording works as regular loop function, while you press CTRL1(LOOP) footswitch, it starts to record the phrase loop.
*AR = Auto Recording will stand by while you press CTRL1(LOOP) footswitch, once you hit the strings, it will start to record your phrase loop.

You can download the QuickTone™ editor from the MG-400 product page. An intuitive interface is provided for tweaking parameters, dragging block order, setup SCN, save patches, load patches, export patches, load IRs, set up USB routing and CTRL SETTING; all by simply using QuickTone™.

USB Audio Interface
For home studio and silent practice, the MG-400’s USB audio capabilities makes it the Swiss Army Knife of guitar audio interfaces. Connect it via USB to your PC, and you can record tracks, reamp, and even do livestreaming with the MG-400.

In Normal mode, you can choose Loopback to play the playbacks from PC when doing a live stream.

Re-amp: MG-400 offers Dry Out and Re-amp recording applications.

  • 2.8” 320*240 color LCD with intuitive UI.
  • NG, CMP, EFX, AMP, IR, EQ, MOD, DLY, RVB, P.L | 10 independent moveable signal blocks.
  • White-box Amp Modeling & Pre-efx algorithm offers realistic playability and analog-chaos response.
  • 512 samples IR resolution and USER slot with each patch. (additional 12 IR COLLECTION slots)
  • Electric guitar amp models, bass amp models, and acoustic simulation IRs with related acoustic amp models.
  • Input trim under SYSTEM MENU.
  • 5 output modes with global 3 band EQ for quick tone tweaking. (Besides STUDIO DIRECT, others will disengage IR signal as default.)
  • PARA. FOLLOW function can track your effect tweaking habits.
  • USB recording interface, firmware update, QuickTone™ edit software.