Posted on by Walter Bryant

Rack-mount gear has become somewhat of a lost art for guitar players since the late 90’s. Nonetheless, rack gear is great for people who want programmability of preset tones, the ability to interchange components, and those who love seeing bright lights flicker as all of your gear goes to work! So for the rack-gear heads that still exist on this earth, we’ve compiled what we think are the 10 best rackmount pre-amplifiers of all time.

Have a look through the list below and let us know what you think! 



The ADA MP-1 was a legend for it’s superior versatility at the time of it’s release. Since first becoming available during the 80’s, players vied after it for it’s midi switching capability via footswitch. Paul Gilbert is most famous for his loyalty to the amp during the spawn of his career.  It runs on two 12AX7 preamp tubes and has three main voicings — Solid State, Clean and Distortion. One downfall of this amp stems from it’s lack of an input volume control, but thanks to a host of mods available nowadays for this thing, one can look really look past this minor flaw. On top of that, you can find them used for around $250! A steal for 80’s tone-in-a-box.


Line 6 POD HD Pro




A comparable alternative at a fraction of the price to the Axe-Fx (which also made the list), the Line 6 Pod HD Pro offers a ton of amp models and effects within it’s 2U rack interface. With over 100+ premium effects, 16 different cabinet models, and even eight microphone models, the Pod HD Pro gives you complete control over every aspect of your tone. All of this is complimented by an intricate display that lets you know exactly what your virtual signal path is. Add the ability to use a mic, bass, or your Line 6 Variax guitar for recording or live scenarios, and you’ve got the best of every realm of music-making at your fingertips. Oh, and to answer the most important question: Does it djent? Yes.


Mesa Boogie Studio Preamp




A now affordable alternative to the Tri-Axis and other Mesa Boogie Amps, the Studio Preamp contained all of the versatility one would expect from a Boogie. This 2-space machine is based on the classic Mesa Boogie Mark IIC+ amplifier, but in the popular rack-mountable form of the late 1980s. It features 5 preamp tubes and a blackface circuit, so it’s perfect for those chasing after a Fender-esque clean or 90’s mid-gain lead tone. And like most Mesa’s, you’ll get a convenient EQ for those final tweaks.


Mesa Boogie Racktifier




Making their second appearance on our list, Mesa Boogie delivers with the Dual Rectifier Rackmount (appropriately nicknamed the “Racktifier”). This 3-U behemoth is simply a Dual Rectifier Head, and is one of the very few rackmounts to contain a pre-amp and power-amp all-in-one.  The Racktifier is made for those who simply want the dual rectifier sound, but have the “rack-gear bug”.


Mesa Boogie Tri-Axis


Made famous by Dream Theater guitarist and loyal Mesa Boogie endorsee John Petrucci, the Tri-Axis presents the absolute best of modern rock and metal tone with a touch of that signature Mesa Boogie character. If you scoured the Petrucci forums in the 90’s and early 2000’s, you’d be the first to know John had quite a few of these, both live and in the studio. It was the Tri-Axis that contributed to the now legendary sweet singing tone he achieved on countless DT albums. The first thing you’ll probably notice about the Tri-Axis is it’s unusual interface, which features digital numbers and arrow buttons instead of knobs.  The Tri-Axis also boasts five 12AX7’s into one rack space. Furthermore, you can achieve tones from Mesa amps like the Mark I, Mark IIC+, Mark IV™ and much more.


Soldano/Caswell X99



The x99 is as Soldano as an amp can get; its purple! The X99 (a step above the 3-channel X88) is a unique MIDI-controlled preamp, featuring Tim Caswell’s innovative system of real-time-controllable motorized knobs. Modeled after the SLO, the X99 has got the Soldano character that everyone’s grown to love. If you find one, let us know! Like most discontinued Soldano’s, the X99 is virtually impossible to track down.


Custom Audio Electronics 3+/3+ SE


Originally designed by John Suhr and Bob Bradshaw (a legend in rack-gear rig building), it can be assumed that this machine was built with superior quality and a ton of tone in mind. Well, boy did it deliver all of that and then some! The first and only CAE rackmounted guitar preamp to ever have been produced was a 2-spacer, featuring 3 independent channels for clean, crunch, and lead. One of the notorious drawbacks with preamps has always been the loss of pick attack. However, the CAE never had this issue, providing a wealth of clarity through every channel, and even cleaning up when you rolled back the volume on your guitar to get those classic tones.


Bogner Fish

As successor to the Bogner Triple Giant, the Fish is a pre-amp with a legendary status, due to it’s unique character and it’s 4-channel configuration. Originally introduced in 1990, the unit was limited to 250 pieces, and is a rare find now-a-days. But thankfully, Bogner decided to reintroduce the Fish, featuring a “Country”, “Shark”, “Strato”, and “Brown” channel. Just like the original, this amp can take on just about any style you throw at it!


Axe-Fx II


The weapon of choice for today’s modern recording musician, the Axe-Fx is as good as it gets in terms of modeling amps. Used by countless musician both live and in the studio, this machine has proven to deliver for just about every musical style under the sun. Notable users of the Axe Fx include Alex Lifeson, Steve Vai, Misha Mansoor, and many others famous musicians. The Axe-Fx II features a high resolution speaker simulator with 150+ “Factory” models and room for 512 “User” cab locations.  It contains a vast virtual inventory of hundreds of vintage and modern guitar amps, speaker cabinets, guitar stompbox and studio effects, and more. The options are pretty much endless.


Soldano SLO-100 Rackmount



The godfather of all that is sought after in rack gear; behold, the Soldano SLO Rackmount Amplifier. Those of you that have heard of the SLO (Super Lead Overdrive) already know that this thing can be brutal when it comes to lead tones. Possessing one of the tightest crunch and overdrive channels known to man, the SLO Rackmount is hailed as a grail piece of gear for many guitar players. The SLO-100 offers two channels, Normal and Overdrive, each with independent Preamp gain and Master Volume controls.  A footswitch is also provided for effortless noise-free switching between the two channels.  The Normal channel has a Bright switch and a Clean / Crunch gain selector switch.  Standard features include a tube-buffered effects loop and a slave output.  Bass, Middle, Treble, and Presence controls provide the tone shaping.  From Clapton to Van Halen, from Warren DeMartini to Lou Reed – and from you to Mike Soldano himself, the SLO is simply the player’s choice.


“Honorable Mention”

Langner DCP-1 Creator



Designed by Todd Langner (who also engineered the ADA MP-1), the Langner DCP-1 possesses somewhat of an infamous reputation. Very few know about it, but everyone who does, swears by it’s greatness. Built with much of the same blueprint as the Bogner Fish, the Langner features two independent channels with fully adjustable boost functions. Using five 12ax7a tubes, it’ll produce the glassiest cleans to the highest of high gain tones. Presets can be front panel selected or footswitched. If you’re into rare gear, this is the amp for you. Good luck finding one!