Always consult the official Owners Manuals first


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Preamp and power amp

Most traditional guitar amplifiers have a preamp and a power amp section, sometimes combined, sometimes separated. The preamp is responsible for tone and gain, the power amp makes things loud (real amplification) and may add some distortion and character of its own to the sound.

Fractal Audio's amp modelers provide virtual equivalents of these preamps and power amps, combined in Amp models. Many traditional heads, combos and racked preamps have been modeled by Fractal Audio.

The devices also provide many other effects, and, depending on the unit, they can reamp a recorded dry signal, create a Tone Match of a real amp or recording, capture Impulse Responses, and more.

See Amp block for more information.

Amplification through traditional guitar speaker or Full Range Flat Response (FRFR)

An amplifier, either real or virtual, needs a speaker, which can also be real or virtual, to sound good. Amplification is required to make things loud. Usually this means using either a traditional guitar cab with a power amp, or a so-called FRFR monitor/cab.

Traditional guitar cab and power amp

A traditional guitar speaker will give you the familiar, fairly easy to set up, amp/cab in the room tone. This does limit possibilities however, because any sound you create will be colored by that particular guitar speaker.

When using a traditional cabinet, the preset shouldn't use a Cabinet model. If it does, disable it or disable Cabinet Modeling in the processor's Setup menu.

A hardware power amp is required to provide a strong signal to the speaker. This can be a guitar-oriented power amp, head or combo, which will add its own coloring to the sound and also decrease the possible tonal variations. This usually sounds best with Power Amp Modeling disabled in the processor's setup menus.

More popular is a so-called neutral power amp which relies on the virtual power amp of the modeler, so keep Power Amp Modeling enabled in the Setup menu.

See Power amp and guitar speaker for more information.


Alternatively, you can use Full Range Flat Response (FRFR) sound reproduction and amplification. This requires a FRFR speaker and a neutral power amp, either external or built-in. Studio monitors are FRFR by nature, as are some monitor wedges and cabs, high-quality PA-systems, and headphones.

FRFR systems, including direct recording require Cabinet Modeling because the signal doesn't go through a traditional guitar cab. Fractal Audio's amp modelers provide many built-in cabinet models. They also allow loading external cabs, known as Impulse Responses (IRs).

Important: When using an FRFR sound system with cabinet modeling, you're listening to the sound of a miked speaker, which is a different sound than that of a guitar speaker cabinet. A virtual cab (almost always) represents the sound of a speaker that was captured using one or more microphones placed very close to the speaker (referred to as nearfield or close-miking). The sound of a guitar speaker at a certain distance is referred to as far-field or in-the-room. Because of the close proximity of the recording mic to the speaker, the FRFR sound has more highs and lows, and has the characteristics of the microphone baked into the captured sound. It can take a while to get accustomed to the FRFR sound, but just realize it's the same tone you hear at a concert or when listening to recorded music.

See Full Range Flat Response (FRFR) more information.

Cutting through the mix

Many players who start using a digital modeler and take it to rehearsals and gigs, using FRFR amplification, find it difficult to cut through the mix. Turning up the volume doesn't solve this. This can be caused by many things but the primary two are:

Input and output clipping

Clipping means that a signal exceeds the limits. While analog clipping can sound pleasing, digital clipping sounds horrible, something that you'll want to avoid.

Clipping can occur at various stages in the device.

Input clipping 
Input clipping means that the incoming signal from the guitar to the processor is too hot or strong. To fix it, turn down Input Sensitivity or Input Pad in the modeler's Setup > I/O menu until the warning disappears.
Output clipping 
The Output LED indicates that the signal level in the effects chain is too hot for the digital-to-analog (DAC) converter at the end. Adjusting the Input Level will not solve this. Instead, decrease the digital level somewhere in the chain, preferably using Level in the Amp block, or in the Output block. The Preset Leveling Tool in Edit is convenient when working with those two settings.

See these links for more information:

Parameter paralysis

The sheer number of parameters and possibilities in Fractal Audio's processors can easily dazzle and confuse users. Sometimes it's handy to be able to fall back on a reference tone.

The Band-Commander (clean tone) and Friedman BE (dirty tone) amp models, both at default settings, provide great baseline tones. Combine them with the factory cab model Legacy 103 at default settings. Listen to the sound with good quality headphones or through studio monitors that provide a flat response.

See Soundclips for reference purpose to hear the sound of various guitars through the modelers.


Always read the Owner's Manual.

G66, the European distributor of Fractal Audio products, encloses a great quick start guide with the delivery of each new Axe-Fx III, FM3 and FM9: G66 Beginner's Guide