Mesa Boogie TriAxis Review – King of The Rack Preamps!

Hello there and welcome back to yet another great article for you! This time we will be looking at possibly one of the best tube guitar preamps ever known to mankind, the Mesa Boogie TriAxis!

In this Mesa Boogie TriAxis review, I will be providing you with some solid information as well as multiple TriAxis demos that I have prepared for this article.

As many of you already know, from the 80s to almost 2000s, all-tube, MIDI-controllable guitar preamps were on the rise and very popular among guitar players. However, with the introduction of guitar amp simulation software and processors, they lost a big share of the market and slowly disappeared.

There are still guitar players out there who have a huge interest in these legendary tube preamps and are looking for them in the used market. As I am also very interested in preamps and a very big fan of the designs that are so advanced and ahead of their time, I can’t resist but regularly check out the used market for potential tube guitar preamps.

Recently, I was eyeing Mesa Boogie TriAxis preamps on Reverb but never really wanted to invest as I didn’t have time to play much guitar. But once I felt ready, I immediately jumped on an offer and got myself a TriAxis v2.0 TX4 Recto Board version.

As most of my regular visitors are already aware, I almost always play through KRK Rokit G5 studio monitors using either guitar amp plugins and software or my beloved ENGL E570 tube preamp with IRs.

Right after I placed my TriAxis within this setup, I was blown away by the tones it was able to generate. Even though I don’t have a tube power amp and proper guitar speakers, it sounds like any Mesa Boogie you could think of!

Before we go into the review and TriAxis demo video, let’s first have a look at the features of this ingeniously designed tube preamp.

About Mesa Boogie

Mesa Boogie is a legendary name in the world of guitar amplification, renowned for crafting amps and preamps that have defined the tone of entire eras of music. From the early days of boutique amp innovation to the heavy-hitting sounds of modern rock and metal, Mesa Boogie has consistently set the standard for tonal excellence and versatility.

With a product lineup that includes the groundbreaking Mark series, the genre-defining Dual Rectifier, and highly sought-after preamps such as Studio, Quad, TriAxis and Rectifier Recording Preamp, Mesa Boogie continues to be a cornerstone for musicians seeking world-class sound.

In the late 1960s, the mastermind behind the Boogie, Randall Smith began modifying Fender Princeton amplifiers in his Petaluma, California shop. These “hot-rodded” Princeton featured higher gain and richer distortion, capturing the attention of top-tier guitarists.

Carlos Santana famously described his experience with one of Smith’s amps as, “Man, this thing boogies!“—a phrase that inspired the company’s name.

The 1970s: The Mark I

Mesa Boogie entered the spotlight in 1971 with the release of the Mark I amplifier. It was revolutionary, featuring cascading gain stages that allowed guitarists to achieve creamy sustain and high-gain tones previously unavailable in other amps.

The Mark I became a favourite of artists like Santana and The Rolling Stones, offering a compact design without sacrificing power or tonal clarity.

Check out the entire Mesa Boogie catalogue on Thomann here

The 1980s: The Mark II and Studio Preamps

The 1980s saw the debut of the Mark II series, which introduced innovations like channel switching, allowing players to switch between clean and overdriven sounds seamlessly.

The Mark IIC+, a standout model from this era, became legendary for its tight, aggressive tone, used by Metallica on their seminal album Master of Puppets.

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During this time, Mesa Boogie also ventured into standalone preamps, such as the Studio Preamp and Quad Preamp, which offered players studio-grade tone shaping and versatility. These products became staples for guitarists seeking high-quality sounds for both live and recording environments.

The 1990s: The Rectifier Revolution

In 1991, Mesa Boogie released the Dual Rectifier, a game-changing amplifier that defined the sound of modern rock and metal. With its massive gain, tight low end, and raw aggression, the Rectifier series became the go-to amp for bands like Korn, Limp Bizkit, and Tool. The Rectifier’s impact on the sound of grunge, nu-metal, and alternative rock cannot be overstated.

The 2000s and Beyond: Versatility and Expansion

The 2000s brought further evolution with the Mark V, which consolidated the features of previous Mark models into one amplifier, and the Roadster and Road King series, offering unparalleled flexibility for touring musicians.

Mesa also introduced compact models like the Mini Rectifier and California Tweed, catering to players seeking Mesa’s legendary tones in portable formats.

Legacy and Modern Era

In 2021, Mesa Boogie was acquired by Gibson, ensuring its continued legacy while maintaining its roots in Petaluma, California.

Today, Mesa Boogie remains synonymous with innovation and quality, beloved by guitarists worldwide for its legendary amps, preamps, and dedication to tonal perfection. Whether it’s the iconic tones of the Mark I, the brutal attack of the Dual Rectifier, or the finesse of their preamps, Mesa Boogie has left an indelible mark on music history.

Mesa Boogie TriAxis Features

Mesa Boogie TriAxis was first introduced in October 1991. Even though there were a couple of different versions or iterations of it, the main features were pretty much the same. It has 5 12AX7 or ECC83 tubes, and ships with Mesa Boogie branded tubes.

On the front panel, you have ahead-of-its-time digital controls that will allow you to shape your tone as well as store them in your favourite combinations along with programmable footswitches and FX loops.

Accessing Programs and Presets on TriAxis

You can consider “Programs” as MIDI locations and “Presets” as sounds. To access programs, you need to press the “Shift” key one time and then use the arrows below the Gain, Treble, Middle, Bass and Lead Drive windows. Once you’re on the desired program, you can then press “Enter” and access the program listed at the location.

To access “Presets” within the programs, you need to press the “Shift” twice and activate the “Preset” window. And then select your desired preset using the arrows below the “Preset” section.

There are a lot of features here such as mapping a preset to a program, copying presets to another preset location, setting MIDI channels, dumping and receiving the MIDI and also recalling factory presets and many more.

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To understand these in greater detail, I suggest you check out the official manual. Unfortunately, there’s only a single version of the manual and the modes may differ as there were different iterations of this unit. However, you can easily learn all the functionalities by reading this manual carefully.

Check out Mesa Boogie TriAxis manual here

MIDI IN/OUT/THRU

On the back of the TriAxis, you also have standard MIDI IN/OUT and THRU for your MIDI operations. There’s also a coax power jack for phantom power with which you can power up your MIDI controller (7-pin).

Switch Jacks

There are 4 separate “Switch” jacks that you can use for controlling or activating external devices (specifically made for Boogie’s products). These are “Tip to Ground” function switches and if you want to use them with any external device other than Boogie’s, you need to contact the manufacturers.

Output Jacks

There are also a pair of “Record” and “Output” jacks on the back of your TriAxis. Record outputs try to imitate an analogue speaker simulation which you can directly record into your DAW. But note that, these were designed in the early ’90s, so do not expect IR-quality direct recording.

Also, using a pair of standard outputs, you can connect your TriAxis to a power amp or an audio interface and then use IRs to directly record.

The Controls on the Front Panel

Boogie TriAxis features pretty standard-looking controls on the front panel. But with some slight Boogie twist as usual! You have your “Gain“, “Treble“, “Middle“, “Bass“, “Lead Drive 1” and “Lead Drive 2” as well as “Master“, “Presence” and “Dynamic Voice“.

To understand what Boogie suggests for setting up the gain stage and how these controls react with each other, you should check out the official manual.

Check out Mesa Boogie TriAxis manual here

As you can see, you have 2 Lead Drives and these correspond to the different modes that the unit offers. So when you are on one of the e.g. Lead 1 modes, only Lead Drive 1 can be used. In this case, adjusting Lead Drive 2 won’t do anything to your sound.

Apart from standard controls, you may already notice there’s also a control named Dynamic Voice. Dynamic Voice is a unique feature of the TriAxis. It’s designed to include Boogie’s famous 5-band EQ with slight differences. It does not only act as a graphic EQ but also as a blend of dry and EQ’ed signals at the same time.

The higher you set it, the higher the dry/wet signal gets as well. When it’s set at 10, the whole signal is passed through the Dynamic Voice.

To understand how these Dynamic Voice values refer to specific 5-band graphic EQ curves, please have a look at the image below (taken from the manual).

The TriAxis Modes

TriAxis features 8 preamp circuits from Boogie and can be easily considered the encyclopedia of Boogie tone! These preamp circuits are placed under 3 main categories Rhythm, Lead 1 and Lead 2.

Before we dive into details, I would also like to share the modes overview taken from the official manual. Note that, this belongs to the current, latest manual you can find on Mesa Boogie’s website and doesn’t mention the “Recto Vintage” circuit. For the different versions of TriAxis, please read on and check out the versions section.

Rhythm Modes

Under Rhythm Modes, you have Green and Yellow modes.

Rhythm Green is more like a vintage, Fender Black Face-style circuit. It’s designed with a lower bass response but with quite a lot of sub-harmonic bass frequencies. The top end is also lower than the Rhythm Yellow but may be perceived as higher or lower depending on how you set the midrange control.

When the midrange is set to lower settings, the upper harmonics become more pronounced. With these settings, setting also the gain control lower, you will have bubbly, elastic high frequencies and big, open low frequencies.

Setting the gain and midrange around 5.5 to 7.5 also generates great usable tones defined as bold and pushed yet still clean. On top of that, maximizing the gain control and midrange generates excellent solo sounds as well. According to the manual, this mode was inspired by Fender Bassman 4×10 amps then later redefined as Mesa Boogie Mark 1.

Rhythm Yellow on the other hand features a much different response than the Rhythm Green mode. Mostly on the bottom end in terms of amount and frequency density. Rhythm Green mode is defined as a tighter and quicker attack. Also, the top end is more percussive yielding a more open, clean sound.

This mode can be traced back to Boogie Mark IV, III and IIC+ according to the manual. Both these Rhythm modes feature a dynamic bright circuit that causes the gain control to act as an additional tone control. The lower the gain, the more top-end harmonics are allowed to pass through. When the gain is set around 3.5 to 5.0, it generates great tones with a lot of sparkles for almost mix-ready funky guitar tones.

When the gain is increased to around 6.5, it becomes more aggressive and around 8.5, it starts delivering semi-clean tones that will sit very nicely in the mix as well. Above 8.5, it acts as a lead mode. So even though, it says Rhythm mode, you can already have so many different guitar tones that you can shape with the controls and TriAxis’ interactive circuits!

The manual includes a lot more tips and tricks on each mode, so I highly suggest you check it out yourself and read it carefully. As Boogie had put so much time into making these circuits perfectly musical, as they suggest one should be just relaxed and take their time to discover the endless possibilities that TriAxis offers!

Lead Modes

Lead modes consist of 6 different modes under Lead 1 and Lead 2 modes. Let’s have a look at them below.

Lead 1 Modes

Lead 1 modes are based on more traditional and older Boogie circuits, meaning that they all feature pre-tone-control gain circuits. So boosting the gain control within this mode pushes the preamp tube before the tone controls. With this approach, these circuits can generate guitar tones that are larger but less focused. These can be also described as loose and more spread-out tones.

As opposed to the rear-end approach in the circuits, this design allows it to pump a lot more bass without being flabby or cloudy. Therefore, it’s ideal for hard rock and metal players who like to maximise their gains. Mesa Boogie specifically recommends Lead 1 Red mode for these kinds of applications. Boogie also suggests that one should first try to explore these modes without Dynamic Voice engaged.

The Dynamic Voice should be still usable with Lead 1 modes but ideally designed for Lead 2 modes as they feature the circuits that are famous for their success in combination with the graphic EQ (post gain).

Lead 1 Green

Lead 1 Green features the Boogie Mark I circuit that was also used by Carlos Santana in his Abraxas album. According to Boogie, Lead 1 Green mode is a true replication of the Mark I (Input 1). It’s defined as fat, warm and round with sweet, sparkling highs just like the Black Face era of guitar tones.

As Boogie can generate the exact circuit, they also featured the unique approach in Mark I featuring the volumes or gains working in series. As a general rule of thumb, the gain set higher than the Lead 1 drive on TriAxis generates more blended saturated sound. The opposite setting generates a brighter and slightly hollow character.

In this mode, treble and middle controls are also designed as active gain controls. So it’s suggested to experiment by adjusting these controls along with gain and Lead 1 drive.

Lead 1 Yellow

Lead 1 Yellow is pretty much the identical circuit with Lead 1 Green but there are several switches activated when this mode is selected. Firstly, this mode features more gain, tighter and more focused sounds.

On top of that, it also has a mid-boost implemented within mid-treble regions, resulting in less bright, more bold and beefy tones. These features in combination with each other provide a liquid feeling. Boogie suggests trying out treble and presence around 5.0 or below. The voice of this mode is darker, warmer and smoother than the Lead 1 Green mode.

Lead 1 Red

Lead 1 Red mode also features a lot of the attributes coming from Lead 1 Green and Yellow modes. But it also features an added focus and punch in the upper mid-range. Because of this punch, it easily cuts through the mix and is very useful for classic and modern gain settings.

The tuning of this mode has a tighter bass response and allows more treble to be added which results in increasing the gain without sounding thin. Boogie suggests setting the gain at 8.0, bass at 6.5, treble at 7.0 and lead 1 drive at 6.0.

Even though, the “current” official manual says this is the classic British Lead mode, the TriAxis v2.0 featuring TX4 Recto Boards has this mode as the Recto Mode.

Lead 2 Modes

As mentioned above, Lead 1 modes were pre-tone-control gain controls. However, with Lead 2 modes, it is quite the opposite. Lead 2 modes feature a post-tone-control gain circuit. This design approach was done for the first by Mesa Boogie company in their Mark II series. Following this groundbreaking approach in amp design, Mesa Boogie also featured this in Mark II-B, II-C+, III and IV series amplifiers.

Generally speaking, Lead 2 modes offer more articulate and focused lead sounds and can be easily described as not so forgiving. All these modes cut through the mix, stay focused much longer and allow players to be heard.

Lead 2 Green

As you remember, in Lead 1 modes amount of gain that you can get differs in each sub-mode. However, in Lead 2 modes, the gain structure and the amount are pretty much similar to each other.

Boogie decided to add legendary Mark II, II C+ and IV circuits to feature in this mode. According to the manual, the Lead 1 Green is taken from Mark IV‘s lead channel and features the mid gain added to the Mark IV in the late ’80s. It’s focused and thick-sounding mode while keeping everything punchy.

As you can see from the section on Lead 1 modes, even though Boogie suggests a lot of settings and starting points in setting up the recommended presets, in Lead 2 modes they came up with a single rule of thumb.

Try setting the gain at 7.0 or 7.5 for blues sounds or articulate mid-gain tones. If you need more than that, try increasing the gain up to 8.0 and see if these work as intended!

Lead 2 Yellow

This is probably one of the best and sought-after modes in the TriAxis. It features the circuit that started everything back in the day, helping guitarists and bands to form one of the greatest guitar sounds that we would listen to on the legendary albums by Lukather, Keaggy, Lynch, Gillis, Prince and Metallica.

Lead 2 Yellow mode is the reincarnation of Mark IIC+ Lead mode, featuring bold, punchy and liquid harmonics! This mode is not only suitable for higher gain settings but also great for lower gain settings as well. Dynamic Voice plays a crucial role in sculpting these tones generated by the legendary post-tone-control gain circuits. 

Lead 2 Red

Lead 2 Red mode is often called the Shred mode by Boogie fans. This mode features a lot more aggressive top end than the yellow mode and boosted upper harmonics. According to the manual, it is a Mark III circuit named Searing Lead. This is often confused with the “Recto” mode which is the Lead 1 Red mode on the TriAxis v2.0s featuring the infamous TX4 Recto Board.

However, in the manual Lead 1 Red mode named Classic British Lead. I’m not sure if this official manual was written for the latest TriAxis builds featuring “Phat Mode”.

Based on my pretty short-term experience with the Mesa Boogie TriAxis, I must say I’m very impressed by all the sounds in this magnificent preamp! Please continue reading the article and check out my demo videos featuring factory presets of the TriAxis!

TriAxis Versions

As you may have already noticed, we keep talking about versions, different modes, and boards, I assume you are guessing there is more than one version of the TriAxis. Mesa Boogie has a dedicated section on their website which you can access here. I’m also adding a quick summary here below.

Version 1

Serial #1 to #1630 – 10/1991 – Software versions 1.4.92, 1.6.3, and 1.6.5 which are classified under Version 1. In this version, continuous control was not a feature. No Phat Mod, no TX4 Recto board.

Version 2

Serial #T1631 to T5199 – 1/25/1993 – Software version 2.0. With this software, continuous control was implemented in the unit and parameters can be controlled via MIDI. TX4 Recto board installed which caused a change in Lead 1 Red mode from “British Lead” to “Recto Vintage” circuit. To quickly check if you have version 2.0, just have a look at the parameters blinking 2.0 when the device is turned on.

Serial #T5200 to T8278 – 3/1997 – Phat Mod. This Phat Mod impacts the upper mids in the Lead 1 Red mode. To quickly check if the unit has Phat Mod or this mode removed, just have a look at the TX4 board by removing the lid and checking the missing parts on the top left.

Serial #T8279 until discontinued – 10/2004 – TX4 board removed due to unavailability of parts. Lead 1 Red reverts back to “British Lead”. No Phat Mod.

Mesa Boogie TriAxis Review

As I mentioned in the beginning, I can’t help but want to try these legendary tube preamps as long as my budget allows me to do so! 🙂 TriAxis was one of the earliest preamps I had ever seen used by my guitar teacher back in 2000. Since then, I have been aiming to own this preamp and try. However, due to not being easy to grab in the used market, I always postponed and ended up with another legendary tube preamp, ENGL E570!

Check out my ENGL E570 review here

I still love my ENGL E570 tube preamp, but as it sounds like ENGL, I find it rather too unique! What I mean by that is if you grew up listening to musicians and bands playing Marshalls, Fenders and Boogies, ENGL wouldn’t sound familiar to them. But it’s also an edge as you can create your own, unique sounds as opposed to just attempting to replicate others.

But when I got my TriAxis, I felt like most of the sounds it can generate were very familiar to me. So I don’t regret this decision and I would like to spend some time with my TriAxis and hopefully will release a lot of comparisons between TriAxis, ENGL preamps and my Marshall JVM410 head.

In short, I recommend any guitar player to try a TriAxis before they leave this world! Seriously, you need to experience this wonderful, ahead of its time design!

It offers so much variety and just feels like an encyclopedia of Boogie tones! Using it is so easy and with its digital parameters, it is a breeze to program and even copy the presets of your guitar hero who also uses TriAxis!

I bought mine used and unfortunately, the right rack ear was kinda bent while transport, however, the unit is in very good condition considering its age! Also, you can see from the image of the circuits, it looks very clean. I think it’s expected that your used TriAxis may have lots of cosmetic issues as well as functional issues as these are ancient devices. But if you are lucky, you can get your hands on one in great condition.

As I mentioned, it immediately sounds like home! If you ever listen to bands and musicians that used Mesa Boogie TriAxis or any Mesa Boogie amps, chances are that you will feel the same! All the sounds will sound familiar to you immediately which is a great thing.

Mesa Boogie TriAxis Sound Demo

Now the fun part begins! To show you what a Mesa Boogie TriAxis sounds like, I prepared some demo videos for you! Note that, I’m not done yet with recording all my guitars, however, you can already watch and listen to my TriAxis demos featuring my Fender American Standard Stratocaster (Custom Shop Fat50 Pickups) and Epiphone Les Paul Custom Ebony (ProBucker2 and ProBucker3 Pickups). The signal chain for every TriAxis video will be the same with different guitars.

In the series of videos, I aim to provide you with useful videos to demonstrate Mesa Boogie TriAxis presets!

Signal chain: Guitar >  Mesa Boogie TriAxis > Marshall JVM410H (Power Amp Send) > RedSeven Amp Central (using Celestion V30 IRs featuring SM57/414 mic combo) > RME Babyface Pro > Reaper (Eventide SP2016 room reverb)

Boogie TriAxis Demo featuring Fender Stratocaster

Boogie TriAxis Demo featuring Epiphone Les Paul Custom

I hope you enjoyed the sounds of TriAxis with different guitars! I believe it’s not easy to find TriAxis sound samples with different guitars featuring all the circuits. Usually, people tend to play only heavy stuff with TriAxis, but I think it has a lot more to offer. You have the entire Boogie history in a compact, programmable box which is way ahead of its time! Cleans and overdriven sounds are so sweet and feel awesome in your hands!

TriAxis DI Out Test

I also wanted to demonstrate the TriAxis DI out for you guys. As you may guess, TriAxis has a built-in DI out that you can use for recording the signal with a built-in speaker emulation.

TriAxis is 30+ years old and you might expect that this would yield terrible results. However, when I first tried it, I was so impressed that I couldn’t stop playing my TriAxis for a very long time!

It was totally usable and fun to play. Of course, there’s no comparison between a modern IR and an old DI out with speaker emulation. Reactive loads and IRs are absolutely superior in terms of feel, response and flexibility. Direct out feels a lot more stiff, but still, if you think about how old this design is, you will be surprised about the results!

In this Mesa Boogie TriAxis Recording Out test video, I only used my Epiphone SG Custom Ebony and directly recorded the recording out into my DAW via the RME Babyface PRO FS interface. I also added Lexicon Room Reverb for the ambience effect.

How Does TriAxis Compare to Plugin Versions?

As you may know, there are multiple plugin versions on the market by various software companies. So I also wanted to provide you with a simple comparison using the same video you just watched above.

While recording the “recording out video”, I also captured the DI signal using my Radial ProDI DI Box, then basically used the same IR and fed these DI signals through Mercuriall ReAxis and Nembrini Cali Axis.

By doing that, I ended up with 3 different TriAxis videos so you can easily compare these plugins against the real deal.

In my opinion, Mercuriall ReAxis is the best in terms of feel, texture and overall authenticity. It also comes with everything you need, effects, booster, cab sim and gate. So if you are looking for a software version of TriAxis, look no further but get the Mercuriall ReAxis!

Where to Buy TriAxis?

If you are ever looking for TriAxis for sale on the internet, chances are you may find some on Reverb.com and eBay as well. There are even almost brand new conditions pop out from the forgotten storage of an abolished guitar store here and there.

Check out Reverb.com for Mesa Boogie TriAxis for sale!

Even though version 2.0 TX4 board is considered the holy grail of TriAxis, I believe other versions also sound great. But if you want that vintage Recto sound which is great in my opinion, you may need to stick to the common approach by Boogie lovers!

As I mentioned in the article, there are some guitar gear that you must try before you leave this world! We are living in a very lucky era as electric guitar players and can try many guitar gears which belong to previous eras and not all of them are necessarily priced like crazy!

TriAxis is one of them, they still retain their value but you will not see anyone charging 5K for a used TriAxis. Ready to pay about 1400/1500 Euros in Europe for this version and a lot less in the USA.

Is Mesa Boogie TriAxis worth trying? Absolutely! You will be blown away by every sound and how these feel at your fingertips!

Update: As the craving for testing and experiencing tube guitar preamps never stops, I traded this with a Mesa Boogie Rectifier Recording Preamp so I could publish an article on this legendary beast as well!

Check out my Mesa Boogie Rectifier Recording Preamp review here

I hope you find this Mesa Boogie TriAxis review article honest and insightful! Thanks for visiting my blog and supporting me so far! I will hopefully see you in the next review here!

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