What is the Axe-Fx? Well, let's start by telling you what it isn't. It's not a modeler in the strict sense. Although it has cabinet emulation and different amplifier "types" it does not attempt to model any effect exactly. Rather the Axe-Fx was designed to simply provide the effect as originally intended and with the utmost quality. All effects can be described in terms of their desired sonic manipulation. All effect processors, whether "stomp boxes" or otherwise, process the input signal to get an output signal, simple as that. However, some processors obviously do better than others. The Axe-Fx approaches effects processing as a strict set of specifications and implements those specifications. For example, the wah effect in the Axe-Fx is not intended to model any of the classic wah-wahs. Instead the input-output relationship of a wah was distilled into a set of specifications. From there the effect was designed to exactly meet these specifications. There is no "black magic" or obfuscation. The effect does exactly what it should do. Inherent in this approach is a degree of flexibility that you do not get with other processors. In our wah example this allows you to set the sweep range, "Q" and other parameters. Most modeling processors do not allow this level of control. The Axe-Fx’s amp, drive and cabinet simulations, however, are very faithful reproductions of the originals, but without the drawbacks of the originals. What this means is that they sound like the originals but are easier to adjust and provide more flexibility and a wider range of tones. For example, the Brownface amp sim sounds remarkably like a particular classic amp however the AxeFx contains working midrange and presence controls. Also the tone controls are much more responsive providing all the tones of the original plus new tones that the original could not achieve. Once again the philosophy is practicality and presenting the “effect” as it was originally intended. The Axe-Fx does not use any analog processing or any tubes. If you look inside the Axe-Fx you will not see any glowing tubes or any of the revered op-amps that the analog pundits claim offer mystical sonic properties. What you will see are modern, high-quality components that offer specifications and performance far exceeding any of the aforementioned devices. The Axe-Fx does contain, however, very accurate digital replicas of actual vacuum tubes. We gathered up some classic tubes and measured their transfer functions and then stored these transfer functions in the Axe-Fx’s massive brain. Our replicas are so exact that we can reproduce the harmonic spectrum of a real tube amp with amazing accuracy. Most modelers don’t even come close. OK, so what does it do? Well, the Axe-Fx is fully routable, fully programmable, real-time controllable, multi-effects processor. Whew, that's a mouthful. Let's examine each of these attributes:   Routability: The Axe-Fx allows you to place effects in any order and in series or parallel. Also, the effects loop is routable as well so if you use your Axe-Fx with a preamplifier you can place the preamplifier in the effects loop and run effects both before and after your preamp. Some effects work better when placed before distortion (which your preamp would provide) and others work better after. By providing a routable effects loop the Axe-Fx allows unrivaled flexibility. Programmability: The Axe-Fx allows extensive programmability of each effects parameters. You are not constrained by the limitations of "one-knob" processors where little if any editing of parameters is offered. In addition, many effects offer advanced editing capability allowing in-depth programming. Usability has not been sacrificed though as most effects have a basic setup page allowing quick access to the most used parameters. Controllability: Many of the parameters in the Axe-Fx are controllable in real-time. Both internal and external controllers can be attached to various parameters offering dynamic control of an effect. Additionally these controllers allow mapping the control value to the effect parameter through a transform so even greater control is afforded. Multiple Effects: The Axe-Fx has all the classic effects plus a few new ones. And for most effects you get two instances so you can really create some huge sounds. The Axe-Fx works on the principle of an "effects inventory". You take an effect out of inventory and place it in the routing grid and then connect it to other effects and connect controllers to it (if desired). If an effect has multiple instances you can withdraw another instance of that same effect from the inventory and place it at another location in the grid. The effects inventory is listed below along with the number of instances available: Noise Gate (1) Compressor (2) Graphic Equalizer (2, 4 for the Ultra) Parametric Equalizer (2, 4 for the Ultra) Amplifier Emulator (2) Cabinet Emulator (2) Reverb (2) Chorus (2) Flanger (2) Phaser (2) Rotary Cabinet (2) Wah-Wah (2) Formant Synthesizer (1) Tremolo/Panner (2) Delay (2) Multi-Delay (2) Filter (2, 4 for the Ultra) Pitch Shifter (1, 2 for the Ultra) Drive (2) Stereo Enhancer (1) Mixer (2) Effects Loop (1) Feedback Send (1) Feedback Return (1) Two-Voice Synthesizer (2, Ultra only) 16-band Classic Vocoder (1, Ultra only) Multiband Compressor (2, Ultra only) Crossover (2, Ultra only) Expander / Gate (2, Ultra only) 40-tap “MegaTap” Delay (1, Ultra only) Quad-Stereo Chorus (2, Ultra only) Resonator (2, Ultra only) Ring Modulator (1, Ultra only) Volume / Pan (1, 4 for the Ultra)   Despite the huge arsenal of effects at your disposal, the Axe-Fx