You are here

Mercuriall ReAxis

Guitar Amp Modelling Plug-in By John Walden
Published May 2018

Mercuriall ReAxis

Mercuriall’s painstaking recreation of a classic Mesa guitar preamp offers more than just rock nostalgia.

Guitar rig modelling is now a well-established part of the computer-based studio. While most such modellers go for the ‘more is more’ philosophy, with a single package offering the user a take on every classic amp, cab and effect known to man, Mercuriall offer a more niche approach. For example, their Spark plug-in emulates four very specific flavours of Marshall, while the Tube Amp U530 (reviewed by Sam Inglis in the November 2016 issue) pays homage to the rackmounted Engl E530 preamp which is very much a tool for seven-string, down-tuned metal players.

If you are beginning to suspect that Mercuriall favour rock and metal guitar tones, their latest offering won’t change your mind. ReAxis is a detailed, component-level, recreation of the classic Mesa TriAxis, a rackmounted preamp launched in the early 1990s and boasting some very high-profile users including John Petrucci and James Hetfield. The originals are still sought-after items, with a second-hand unit likely to cost you somewhere north of £800.

Tri Star

The original TriAxis offered eight different analogue preamp circuits derived from a number of classic Mesa amps, including various channels from the Mark I, Mark IV and Mark IIC, plus a ‘British’ circuit for some added variety. The novelty of the TriAxis was that all this analogue sonic goodness was digitally controlled, such that any of the 90 presets could be recalled instantly via MIDI.

ReAxis delivers exactly the same preamp feature set in a virtual format, but adds power amp modelling with three different tube configurations, cabinet modelling with dual virtual microphones in front of four virtual cabs, and a compact selection of both pre- and post-amp effects. This makes it, in effect, a complete guitar rig modelling plug-in, albeit one based squarely on a single product.

The ReAxis UI will be instantly familiar to any TriAxis user, as the hardware’s front panel control set is pretty faithfully reproduced, but with a more user-friendly preset system located on the left. The rather novel (for a guitar amp) digital parameter controls dominate the central section, and Mode buttons on the right allow you to switch between the eight different preamp models.

The lower half of the user interface contains three tabs to access the Pre-FX, Amp & Cab and Post-FX options. A gate, wah-wah and choice of three different overdrive pedals are found in the Pre-FX, while the Post-FX palette offers stereo chorus, reverb and delay. The Amp & Cab tab is also quite flexible, with variants of four cab models, detailed options for mixing and matching between two mic models with mic positioning, and different tube model options for the power-amp stage. The topmost control strip of the plug-in allows you to switch individual components of the modelling on or off and set input and output levels.

By adding a power amp stage and cabinet/microphone modelling, Mercuriall have turned their virtual TriAxis into a complete guitar amp rig.By adding a power amp stage and cabinet/microphone modelling, Mercuriall have turned their virtual TriAxis into a complete guitar amp rig.

Rock Of Ages

The ReAxis plug-in behaved very well in my system, and a side-by-side comparison with Line6’s Helix Native suggested a not dissimilar CPU load. ReAxis ships with a modest selection of presets but there are also plenty of examples to be found online based upon the original hardware.

Mesa is a brand that is closely associated with rock and metal tones, so it is perhaps not surprising that this is where ReAxis excels, and that the presets are dominated by these styles. It recreates the scooped metal sound very convincingly — the D Voice control adds to the standard Bass, Mid and High EQ in this regard, providing extra scoop — but it is also possible to craft more modern, mid-dominated tones when required. The different preamp models offer both different tonalities and different capacities for gain. Oh, and the latter is not in short supply, even before you add in anything from the overdrive models in the Pre-FX section.

That’s not to say ReAxis can’t also do cleans. It can but, just as with a real Mesa amp, I’m not sure it would be my first choice for country or funk. In particular, I struggled to dial in a bluesy ‘just breaking up’ tone that I really liked. However, you can roll from high gain to somewhat lower gain quite convincingly using your guitar, so if rock and metal is where you spend most of your time, and you just need the occasional clean tone for those quieter moments, you probably could get by with just what ReAxis has to offer. Preamp modelling aside, the modest effects selection is pretty well done, and the microphone modelling options give you plenty of additional scope to dial in the subtleties of your tone.

Axis Of Good

The original TriAxis has a cult following amongst rock and metal players, and the plug-in emulation is going to appeal to those who have heard the legend on a multitude of classic recordings, but have never been in a position to own the hardware. Equally, I’m sure it will also be attractive to those who perhaps owned, and then parted company with, an original TriAxis, as a means of revisiting the sound — and operational quirkiness — that that unit delivered. And even if you’re not set on recreating vintage Mesa tones, ReAxis is a great source of rock and metal guitar sounds in its own right, and much more than just an exercise in nostalgia.

Usefully, Mercuriall offer a demo version so you can try before you buy; with a niche product aimed at a niche audience, that’s a sensible approach. However, given the relatively modest cost, I suspect real metalheads will find ReAxis a tempting avenue into a bit of classic metal guitar tone history.  


  • An inexpensive way to experience the world of Mesa’s TriAxis.
  • Impressive array of rock and metal tones available.


  • The quirky interface, although faithful to the original hardware, takes a little getting used to.
  • Not so flexible for cleaner tones.


ReAxis offers a slice of classic rock and metal guitar tone history with the convenience and price of a plug-in. It’s a niche product, but very good at what it does.