First off, we'd like to apologise for the late appearance of this article. There is, however, a simple explanation:
Every time the author turned on the Axe-Fx to explore a new aspect of the latest firmware he 
disappeared into a world of his own. He would return to reality several hours later

with a happy smile on his face, only to discover that
he hadn't written a single word.


For a few updates now we have all been facing the question of what can really be improved in a perfect device like the Axe-Fx II. And as far as new amps goes, the air is getting very thin up at the top. The Axe-Fx II already had almost every amp in the world under the hood – what more could we expect? Nevertheless, we can report the addition of two brilliant new amps since our last article, bringing the total number available to an amazing 189 models.

  • Firmware 15.03 already brought us two fantastic models of the Marshall AFD, Slash's signature amp that really does whet your 'Appetite for Destruction'. The AFD has become for many the definitive Marshall tone and both these models are unbelievably good fun to play, especially at high volume.

  • Firmware version 16.02 now brings us a Vox AC30HW, a hot-rodded model based on an original hand-wired amp with a bypassed tone circuit. This brings an extra portion of gain into the equation, pushing the much-loved AC30 sound into new crunch dimensions.

Many of the further developments in the new firmware concentrate once again on amp modelling - the Amp block has been updated with five new or extended parameters. These are not, however, just some strange knobs that no-one will ever need, but rather powerful and easy-to-use tools:

  • The Saturation switch now has three settings. Alongside 'Off', the saturation circuit can now be used either completely authentically or in the idealized fashion of previous firmware versions.

  • The Power Amp Hardness parameter controls how hard the virtual power tube grid clips.

  • The Slope parameter allows fine control of the virtual speaker's high-frequency impedance curve. This affects how the power amp and speaker interact – lower values result in increased midrange response, while higher values sound more scooped.

Two absolute highlights are the following new parameters:

  • The Variac control adjusts the relative AC line voltage into the amp simulation. Eddie Van Halen himself maintains that the sound he had on the first Van Halen albums was very much a result of the adjustable ('Variac') transformer that enabled him to reduce the voltage and thus make the power amp sag sooner. The simulation sounds like the original, but is easier to use as it also automatically adjusts the output level to compensate for the resultant drop in volume. 

  • The Dynamics parameter opens up a realm of possibilities that none of us had ever dreamed of. Imagine an amp that not only responds perfectly to the dynamics of your playing, but can also react hyperactively when you want it to: play twice as loud and the amp becomes four times as loud. Once you've tried it, there's no going back.

In total there are seven paragraphs in the current release notes regarding improvements in the amp modelling. The output transformer simulation has once again been further developed and now includes even more subtle effects that happen inside a real transformer. The interaction between the power tubes and the transformer has also been taken into account and simulated. The results are difficult to describe, but easy to hear.

The virtual power tube section has also been improved again, resulting in a more realistic simulation, better playing feel, more musicality and an increased 'wow'-factor. While there were already many guitarists who would have preferred to use an Axe-Fx II than a 'real' tube amp, even without all its fantastic control options and unsurpassed effects, we are convinced that number will grow with the release of this new firmware version.

Now that we've almost accidentally mentioned effects: there's plenty of new stuff to report on this front as well. Cliff Chase is not one to rest on his laurels and alongside amp modelling he has also been taking the effects one by one and improving what was already really good. 

The reverb was a stand-out effect in the very first generation of the Axe-Fx and has now been audibly improved, primarily through further development of the simulation of early room reflections, making the spatial effect more lifelike. The stereo width of the effect can now be adjusted and ducking has also been added: just like with the delay, the reverb is only audible when you stop playing, allowing the use of large amounts of reverb while keeping a well-defined, clear tone.

The filter and parametric EQ blocks now have a further type of shelving filter and can thus now recreate the sound of an analogue shelving filter on a classic mixing console. Old passive equalizers with their characteristic sound can now be simulated, also with the graphic EQs. The latter now allow Q-adjustment for all bands.

The compressor has also seen some changes. It can now increase the dynamic range, i.e. it can do the opposite of compression. As in the Amp block, a small change in pick attack can result in a large change in volume, increasing the range of expression open to the musician.

  • A new 'Fast RMS' detector in the Studio Comp compressor type reproduces the fast detectors found in classic rack-mount compressors. (Father to son: "It's all right for you. We used to have to rent a studio. You've got an Axe-Fx II.") 

  • The noise gate too has had the once-over. The new intelligent algorithm has been exclusively developed by Fractal Audio and results in a very musical noise reduction that is remarkable for the fact that you hardly notice it working at all. 

  • Even more drive: those who thought the previously mentioned amps offered too little gain will be pleased to hear that the algorithms for all the drives based on the classic Tube Screamer pedal have been further optimised.

The most powerful engine is useless if the car it is in can't get that power onto the road. The same is true of a multi-fx device if it is difficult to program or complicated to use in a live setting - the user wants to be able to exploit the potential of the device. This is why there has always been an emphasis on easy usability with the Axe-Fx II. That makes it all the more pleasant to hear that Fractal Audio has also been active on this front.

  • Grid navigation has been adjusted slightly to make it simpler and more consistent. The Input noise gate and the Output menu are now integrated into the Layout grid.

  • It is now possible to change presets using just a simple pedal.

  • Further parameters have been opened up for adjustment via modifiers.

  • Since firmware update 15.04 XL users have had an extra 256 preset locations.

Around two dozen small bug fixes have been carried out since our last firmware report. This too is a sign that Fractal Audio is actively working developing its products and is intent on ensuring that the best Axe-Fx II of all time keeps on getting better and better.