Always consult the official Owners Manuals first!


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Pictures of FM3 rigs

Owners of an FM3 proudly show their rigs

About the FM3


Product announcement:

Meet the New FM3 Amp Modeler/FX Processor

Now you can get Fractal Audio’s industry-leading amp and cab modeling, plus a suite of stompbox and studio effects, a powerful foot controller, 4×4 USB audio — and more — all in a compact, rugged, all-in-one, floor unit designed for the studio or stage.

Legendary Amp Modeling and Speaker Simulation plus a Suite of Incredible Stompbox and Studio Effects

The FM3 features our latest ARES Amp Modeling—a technology developed by Fractal Audio for the award-winning Axe-Fx III. It captures the sound — and the equally important feel — of real tube amps, with 265+ models offering an impressive range of clean tones, elusive “edge of breakup”, and everything from warm, touch-sensitive overdrive to face-melting modern distortion.

The FM3 also includes the entire speaker cab impulse response (“IR”) collection from the Axe-Fx III, with a stunning 2,200+ “Factory” choices and 1,024 “User” locations to store custom sounds from free or commercial producers.

As a multi-effects unit, the FM3 truly excels. It includes a superb selection of Fractal Audio’s state-of-the-art effect algorithms. All of the essentials and many exciting innovations are on board: dazzling drive pedals, dozens of delays, reverbs, compressors, EQs, phasers, flangers and other modulation effects, a looper, and much more.

Impressive USB Audio Capabilities — Playback, Record, Re-Amp

With a USB connection to a Mac or PC, the FM3 works as an extremely high quality 4×4 audio interface for playback, recording, and re-amping. This lets the FM3 double as the hub of a portable recording studio.

USB channels are mapped for maximum ease of use. For example, to record the processed stereo output of the FM3, just record inputs 1 and 2 in the computer. Computer inputs 3 and 4 can be used to capture a DI, or to record input 2 L+R in stereo.

Computer playback is also easy and flexible. For studio work, you can mix a project and the FM3 to a single pair of connected monitors and transmit a separate DI to the FM3 for re-amping. For live performances, you can route the stereo FM3 and stereo backing tracks to different stereo outputs.

USB also allows 2-way communication between the FM3 and its companion software applications, FM3-Edit and Fractal-Bot.

A Rugged Floor Unit

The FM3 is housed in a durable steel chassis with protective endcaps designed to withstand the rigors of touring.

Three onboard footswitches – each with variable-color LED ring and mini LCD display — provide both tap and hold functions, which can be customized to do different things on eight different switch “layouts.” The new “Views” feature multiplies the power of layouts, in effect creating a virtual 12-button controller with a 3-button footprint.

In addition, a FASLINK II port allows the FM3 to be connected with up to two Fractal Audio FC-12 or FC-6 foot controllers, providing an exciting array of extended control options.

While designed as a floor unit, the FM3 features an intuitive hands-on interface with the same full-color display and familiar, easy-to-use front panel controls found on the Axe-Fx III.

The unit is powered by a 3-Core “Griffin” DSP with one ARM and two SHARC+ cores providing superior power in a compact format. A dedicated graphics processor allows the main DSPs to be focused on critical audio tasks.

Summary of Features

  • FM3 is a compact floor unit with three onboard switches
  • Hundreds of accurate models with real tube amp sound and feel
  • Features ARES Amp Modeling developed for the Axe-Fx III
  • Includes all factory cabs from Axe-Fx III, plus 1,024 user cab slots
  • Impressive multi-effects capability based on Axe-Fx III
  • Uncompromising sound quality and road-worthy reliability
  • Fantastically flexible 3-button integrated foot controller
  • FASLINK II allows adding up to two FC-12/FC-6 controllers
  • 3-Core “Griffin” Processor plus dedicated GPU
  • Rugged steel chassis with protective endcaps and handles
  • Easy-to-use front panel interface, plus free FM3 Edit software
  • Ultra-low noise instrument input plus XLR stereo main outputs
  • Additional Stereo I/O Pair, plus headphone & SPDIF outputs
  • 4×4 USB Audio, 2 onboard switch/pedal jacks, MIDI In & Out/Thru
  • Easy-to-Read precision Tuner with graph and virtual strobe displays
  • Upgradeable firmware allows constant improvement and innovation


"The Axe-Fx III, FM3 and the other products in development all use the "Ares" architecture. This is a portable client-server architecture that allows easy porting of effects and models between hardware platforms. When we ported the Axe-Fx III models to the FM3 it involved nothing more than copying the file. We created the Ares architecture three years ago and all new products use it. It's a comprehensive hardware and software paradigm that allows any number of clients to communicate with a DSP server. The architecture supports multiple DSP cores. Clients can be located on the same core, a different core on the same IC, a different IC on the same board or on completely different hardware, i.e. an editor running on a PC or a foot controller. For example on the FM3 the UI is a client running on the ARM core. The Ares architecture is even processor agnostic. The Axe-Fx III uses TI DSPs while the FM3 uses Analog Devices. The Ares architecture was a huge undertaking with the ultimate goal of faster product development and easy synchronization of multiple product lines. It allows me to work on algorithms and new models and the engineers can then easily port those to the other products." [1]

"The value proposition of the FM3 is unmatched. It encompasses the entire history of Fractal Audio and all our algorithms and technology developments of the last 15 years." [2]


  • Dimensions: 11.1″ x 9.3″ x 4.05″ (281mm x 236mm x 103mm). The FM3 is the same size as the FC-6 controller.
  • Weight: 7 lbs 1.6 oz (3.22 kg)
  • Processors: SC587, a 3-Core “Griffin” DSP with one ARM and two SHARC+ cores. Dedicated GUI processor. Cabinet modeling runs in a CPU accelerator.
  • Screen: 800×480 high contrast color LCD, 4x12 layout grid
  • Power Consumption: universal power supply, draws < 40 W
  • Fan: yes, side and bottom venting, thermostat-controlled
  • Headphones output: yes, 35 Ohm (except the first production batch, [3])
  • Pedal ports: 2, TRS, 10–100 kΩ max (pedal)
  • A/D conversion: 24-bit, 48 kHz, 114 dB dynamic range, frequency response: 20 – 20kHz
  • D/A conversion: 114 dB dynamic range, frequency response: 20 – 20kHz
  • Instrument input: rear 1/4" phone jack, unbalanced, with “Secret Sauce IV”, 1 megaohm, max. input level: +16 dBu
  • Analog input 2: L/R 1/4" phone jack balanced (TRS), 1 megaohm, max. input level: +20 dBu
  • Analog output 1: L/R, XLR balanced, ground lift, -10 dBv or +4 dBu, 600 Ohm, 20 dBu max.
  • Analog output 2: L/R, 1/4" unbalanced, Humbuster, 600 Ohm, 20 dBu max.
  • USB: Type B port, and Type A port (currently not used), USB 2.0, 4x4 USB Audio (48 kHz fixed)
  • MIDI: IN (5-pin DIN) and OUT/THRU (5-pin DIN)
  • S/PDIF: RCA Coaxial, uncompressed PCM, 48 kHz (fixed)
  • No battery

"The FM-3 doesn't have a battery. It uses EEPROM for system data." [4]

"The A/D converters have 114 dB of dynamic range and are probably the same converters used in the Stomp. The instrument input on the FM-3 uses a dynamic range enhancement technique which boosts the dynamic range to 123 dB." [5]

"The converters in the FM3 are the same high quality as those in the Axe-Fx III." [6]

"FX III is 6 dB higher than FM3 on Output 1. [7]

More in the Owner's Manual


"There's only so much heat you can dissipate in a small chassis. Add to that the requirement for harsh environments (outside, on a hot day in direct sun) and you have to be careful. There actually is a fan in the unit but it's controlled by a thermostat and under normal conditions it doesn't run. Reliability is paramount in a product like this. You can't have it shutting down during a performance." [8]

You can take the plastic end caps off, but you need to keep air space under the unit and to the sides for airflow.

"The main board is roughly the size of the base and is filled with components." [9]

"While the audio path isn't identical to an Axe-Fx III the quality of the path and components is comparable."

(Does the FM3 offer same or better audio path quality (converters-secret sauce-noise) compared to Ax8?) "Better."

"Units from the first production run of FM3 have no headphones jack or circuitry. These units are functionally identical in every other way to later production units with a headphones jack." [10]

"The fan speed is temperature dependent. Be sure to not block the vents on the sides or the fan intake on the bottom. At room temperature the fan will rarely turn on." [11]

"The DSP is NOT designed for a heat sink and doesn't need one." [12]

(firmware 1.05) "The fan now operates at different thresholds than when the ambient temperature was used. It should now spin up at 60°C, switch to high speed at 70°C, and turn off when the temperature drops below 55°C. Also note that on-screen temperature readings may be different than those you may have become accustomed to seeing when the ambient temperature was being measured." [13]

"The entire product line was conceived years ago. The goal was to maximize the number of parts shared between products. The footswitch PC boards do three switches each. An FM3 has one board. An FC6 has two. An FM9 has three and an FC12 has four. All products use the same LCDs, encoders, side plates, etc., etc. This reduces cost and repair inventory. The FC6 and the FM3 are basically the same enclosure. The FC12 and FM9 are basically the same enclosure. This isn't a huge market. Margins are thin so you have to think of ways to minimize development and product costs. Parts bin methodology is the route we took on this generation." [14]


The FM3 is powered by a 3-Core “Griffin” DSP with one ARM and two SHARC+ cores providing superior power in a compact format. The dedicated graphics processor allows the main DSPs to be focused on critical audio tasks. Cab modeling runs in an accelerator. Amp modeling runs on the 2nd core DSP, together with the Delay blocks.

"The processing power of an FM-3 is roughly the same as an AX-8." [15]

"It's not nearly as powerful as an Axe-Fx III but it's a cool little unit." [16]

"The FM3 is not as powerful as an Axe-Fx III. The Axe-Fx III has at least four times the processing power." [17]

"Uses an SC587. The SHARC+ core has essentially the same MFLOPs as the SHARC. The overall processing power is greater than an AX-8 because of the ARM which offloads all the housekeeping stuff, USB, etc." [18]

”The FM3's CPU utilization meters are normalized so that 100% represents the amount of the CPU that can be allocated to audio processing. So you can go right up to 100%. However, if you ever cross 100% things will get shut off without your consent so you still need to be careful.” [19]

(comparing the amp modeling to the Axe-Fx III) "They are the same quality. Certain features were removed to allow the algorithms to run including the bias tremolo, input dynamics processing, and several other inauthentic enhancements." [20]

"We removed all the superfluous stuff (bias tremolo, dynamic presence/depth, etc.) in order to get the core amp modeling to run on the slower processor." [21]

"The Axe-Fx III contains various algorithms that allow you to enhance the amp modeling that don't exist on a real amp. I.e. dynamic presence/depth, input dynamic processing, etc. These were removed to allow the core amp modeling to run on the lower-powered processor." [22]

(Cab block runs on CPU accelerator) "It's a CPU accelerator thing. A second Cab block would use a lot more than 3%." [23]

"FM3 CPU is normalized so it's tricky to get an apples to apples meter comparison with A3 for that reason among others." [24]

"FM3 has an additional core to handle UI/Midi/Footcontoller stuff so that freed up some CPU. Additionally a bunch of little optimizations you find while working in the code for a long time. 1% here, 1% there adds up." [25]

"(...) The DSP power makes it the second most powerful amp modeling product on the market behind only the Axe-Fx III. Adding another DSP would increase the price substantially. The increase would be more than the price of just the DSP since larger power supplies would be required, etc. This would price the unit above our target price." [26]

"The FM3 DSP is three cores and also supports floating-point, has dual DDR3 memory busses, hardware FFT and FIR accelerators, etc."

"The Delay block shares a core with amp modeling on the FM3." [27]

"The CPU % displayed is the primary CPU %." [28]

"The FM3 is somewhere between the AX8 and the II. Probably closer to the AX8. The new SHARC+ DSPs aren't terribly fast. In fact they're a tiny bit slower than the previous generation SHARCs. However you get two DSP cores plus an ARM core in a single package that only consumes a couple watts. They also have dedicated FFT and FIR accelerators whereas the previous generation you could only use either-or. The pipeline in the SHARC+ is a lot longer and there's an extra cycle of instruction latency for many operations which slows things down if you don't code around it. We had to rewrite all our assembly libraries to compensate for this. Pain in the rear. The memory bus is a little faster though and there's better caching which improves overall performance. Still, the SHARCs pale in comparison to the Keystone DSP in the Axe-Fx III. That thing is a monster. But it also costs three times as much and needs a lot of ancillary support ICs. The net DSP cost is probably around 7-8 times higher." [29]

"Under certain circumstances (using an Amp block and two Delay blocks with Diffusion on) the second DSP could get overloaded. The easiest solution at this time was to remove the Diffusion parameter. If we are able to improve the code efficiency we will reinstate the parameter. You have to realize the FM3 has only about 1/5 the DSP power of an Axe-Fx III. Trying to fit all those goodies in there while not sacrificing audio quality is a balancing act. I ALWAYS insist on quality over quantity. That's what differentiates our products. It takes a LOT of horsepower to do it right." [30]

"The converters used in the FM3 have 12 samples of latency which is 0.25 ms at 48 kHz. This is quite typical." [31]

"The III uses (1) dual-core Texas Instruments DSP. The FM3 uses (1) dual-core Analog Devices DSP. The FM9 uses (2) dual-core Analog Devices DSPs. The TI DSPs are much more powerful than the Analog Devices DSPs per clock and run at around twice the clock speed as well. So one TI DSP core is about four times more powerful than one Analog Devices DSP core. If we normalize processing power to the III it would be:

  • Axe-Fx III: 100%
  • FM9: 50%
  • FM3: 25%

So why not use the TI DSPs in everything? Power. The TI DSPs use more power and generate more heat requiring active cooling. They are also more complicated to use requiring dedicated clock generation units, multiple power supplies with specific sequencing requirements, etc." [32]

"FM3 and FM9 use the same SHARC+ family as the QC." [33]

"The Cabinet block uses an FIR accelerator to do the IR processing. This FIR accelerator offloads processing from the CPU and, as such, doesn't reflect in CPU usage." [34]


"The latency is now around 2ms." [35]

"A basic amp + cab preset in the FM3 should be 3.17ms. In the Axe-Fx III it should be 2.2ms. Cab blocks do NOT add latency. However the IR itself may have some leading silence or the peak in the time response might be delayed which would add latency."

Latency should not increase with CPU load.

"Most blocks do not add latency. The only blocks that add latency are Drive and Amp. The reason being that they oversample and oversampling adds latency." [36]

"FM3: 3.3 ms. Latency testing was performed using a pulse into the DUT. Preset in DUT consisted of all possible locations in a single row populated and all but the amp block bypassed, i.e., In->Drive->Eq->Amp->Cab->Delay->Reverb->etc.->Out with all but Amp bypassed." [37]


Read this

Comparing the FM3



Two separate USB-Serial/Audio Drivers are required for Windows operating systems. Available here

No driver is required for Mac operating systems.

Note: when using a USB-C to USB adapter on a newer Apple computer, plug the USB-C adapter into a the port on the Mac first, allow it several seconds to “wake up” and then connect a USB cable and FM3 into the adapter.


Read this: Editors



Read this:

Boot time

"The progress bar during boot indicates presets being copied from FLASH to RAM. If a preset is empty it is skipped so the more empty presets you have the shorter the boot time." [38]

I/O connections


Read this:

"The USB outputs (IN Endpoints) are Output 1 L/R, Instrument In and Input 2 Left." [39]

"The USB-A connector is for a FLASH drive to import/ export presets. However it’s currently not working yet." [40]

“The USB-A port can be whatever we want but it requires writing drivers (or buying them and hooking them into the OS). If the demand is great enough we can look into these things. Peripheral drivers are a lot easier than host drivers and USB-A is host.” [41]

"The USB-A port can provide power if enabled. At this point the port is disabled and reserved for future expansion." [42]

"The USB A port is NOT designed to be connected to a computer. It is reserved for future expansion." (..) "We also looked into the ramifications of doing this and it WON'T damage anything. It just won't work."[43]

(Can it be controlled with a regular MIDI pedal) "Of course." [44]

"The MIDI runs at 5V."

The FM3 is NOT a USB MIDI Device. It uses “COMM over USB” channels for Fractal-Bot and FM3-Edit, but will not appear as a MIDI device in a DAW or other MIDI program.

"MIDI over USB is used for Fractal-Bot and FM3-Edit, but the FM3 does not appear amongst the MIDI devices on your computer. For the purpose of preset changes, cc messages, tempo, etc, it can definitely be controlled by a 3rd party MIDI device or MIDI interface, such as a MIDI Sport." [45]

"The FM-3 does NOT support MIDI-over-USB. Sending MIDI to it over USB can lead to unpredictable behavior." [46]

The FM3 is not effected by phantom power. [47] [48] [49]

The FM3 does not have onboard relays but it can transmit MIDI messages to a 3rd party amp or a dedicated relay switcher.

MIDI-over-USB functionality can be added to the FM3 by using a separate MIDI/USB cable or interface.

"The FM3 is not really geared towards amp integration. It's primarily intended to be a standalone solution with a single fx loop. For amp integration or multiple loops we recommend the FM9 and Axe-Fx III." [50]

Pedal ports

The FM3 has two pedal ports for direct connecting to expression pedals and/or single or dual external switches.

An expression pedal should have a linear resistance taper, max resistance of 10-100 kOhm, and requires a TRS-to-TRS cable. The pedal must be calibrated before use in the I/O menu.

An external switch can be a momentary or latching one, and uses a TS-to-TS cable (single button switch), TRS-TRS cable (dual button switch) or TRS-dual TS cable (two switches). Use the I/O menu to tell the hardware what type of external switch you're connecting and its polarity.

External switches can perform the other or the same tasks as the onboard switches.

The Owner's Manual contains tutorials about connecting, calibrating and configuring a pedal, either connected directly to the device, or via another controller.

The FM3 allows selecting a pedal or switch directly as a modifier source (without assigning it to an external controller first).

The FC-6 and FC-12 foot controllers also allow connecting expression pedals and switches to the controller. These are configured in the Setup > Foot Controllers menu. Read this: FC-6 and FC-12 foot controllers

"You can plug in dual button footswitches into the pedal inputs."

"External switches can do anything the "local" switches can."

"Any button can be assigned to activate the tuner.


Number of presets:

  • 512

About the factory presets:

Effects list

Click on the image below:

FM3 effects.jpg

There's a comparison between the various hardware products in the Blocks Guide.

"Due to the lesser processing power there are fewer instances of many effects, i.e. two instead of four. Channel counts are the same." [51]

"Only one amp block. (...) It does not have all of the Axe-Fx III effects but has the most important ones (no vocoder, etc.)." [52]

"We could potentially do two amp blocks but at reduced quality and I don't want to do that. Part of the problem with other modelers is that they don't oversample enough (and use single-precision in places where you need double-precision). Then you get complaints of artifacts and ear fatigue and all the other things associated with inadequate sample rate and word length. The vast majority of users only use one amp block so we wanted to make something with one very high quality "Ares" amp block." [53]

(Cab block runs on CPU accelerator) "It's a CPU accelerator thing. A second Cab block would use a lot more than 3%." [54]

(comparing the amp modeling to the Axe-Fx III) "They are the same quality. Certain features were removed to allow the algorithms to run including the bias tremolo, input dynamics processing, and several other inauthentic enhancements." [55]

"We removed all the superfluous stuff (bias tremolo, dynamic presence/depth, etc.) in order to get the core amp modeling to run on the slower processor." [56]

"The Axe-Fx III contains various algorithms that allow you to enhance the amp modeling that don't exist on a real amp. I.e. dynamic presence/depth, input dynamic processing, etc. These were removed to allow the core amp modeling to run on the lower-powered processor." [57]

"The changes to the Megatap block have not been ported to the FM3 at this time. They may or may not be ported at some future date." [58]

Reverb on the FM3 defaults to the “Economy” quality mode to keep CPU usage low.

System reset

Read this: Reset system parameters

Buttons, knobs, switches


Navigate and operate

  • VALUE wheel (without push-button function)
  • NAV buttons. On the Home page these let you switch presets (left/right) and scenes (up/down)
  • PAGE LEFT/RIGHT buttons
  • HOME menu button
  • EDIT button
  • ENTER/EXIT buttons. ENTER also jumps to the layout grid from any screen
  • 5 rotary push-buttons (ABCDE) perform various functions in the GUI
  • Output level knobs for Output 1 and Output 2

Onboard switches


Three onboard footswitches – each with variable-color LED ring and mini LCD display — provide both tap and hold functions, which can be customized to do stuff, using switch layouts and views, globally or pre-preset.

The switches can be programmed to:

  • switch presets
  • switch scenes
  • switch channels
  • switch layouts and views
  • turn effects on/off
  • perform utility tasks
  • etc.

This is explained in depth in the FM3's Owner's Manual and in the Footswitch Functions Guide. Read this: FC-6 and FC-12 foot controllers.

Note: on the FM3, the Master Layout menu (MLM) is normally assigned to the Hold function of the middle switch.

Adding an FC controller

The FM3 can be expanded with up to two FC controllers.

FM3 FC6.jpg

"You can hook an FC-6/12 to it. So for small gigs/rehearsals use the FM-3 alone. For larger gigs connect an FC (or two)." [59]

"If anyone is curious the thought process was this:

  1. FM3 alone for rehearsals, small gigs.
  2. FM3 plus FC6/12 for larger gigs.
  3. Axe-Fx III plus FC6/12 for MSG. (Madison Square Garden)

Since the FC6/12 are "thin clients" you can exchange them with the Axe-Fx III and FM3 without having to do any programming." [60]

"FASLINK powers the first FC. FC setup is same as Axe-Fx III." [61]

Read this: FC-6 and FC-12 foot controllers


Firmware 5 and later for the FM3 add these shortcuts to the user interface:

  • Double-tapping EDIT edits the previous block
  • Double-tapping HOME enters the layout grid
  • Double-tapping STORE prompts immediately
  • When on the Home or Layout pages, double-tapping the Quick Entry knobs does the following:
    • A: Enters the Amp 1 menu (A = Amp).
    • B: Enters the Drive 1 menu (B = Boost/Drive)
    • C: Enters the Cab 1 menu (C = Cab)
    • D: Enters the Delay 1 menu (D = Delay)
    • E: Enters the Reverb 1 menu (E = rEverb)

Performance Pages: added in later firmware. These allow fast access to max 10 often-used parameters per page. You can choose these in FM3-Edit on the Perform screen. You can use block parameters, parameters from controllers (including Tempo), global parameters. There are Global Perform and Per-Preset Perform pages. Soft-knobs D resp. E let you jump to the Edit menu of AMP resp. CAB.

HOME page:

  • Press ENTER to jump to the layout grid of the current preset. Press EXIT to return to the Home screen
  • Use NAV LEFT/RIGHT to switch presets
  • Use NAV UP/DOWN to switch scenes
  • Turn knob "A" to switch scenes

AMP block > Output EQ:

  • Press ENTER to flatten the bands, and NAV UP/DOWN to change bands

CAB block:

  • Go to Cab Number field and press ENTER to view the Cab Picker


  • Press-and-hold ENTER to create (or clear) a series of shunts

Block Edit menu:

  • Keep pressing EDIT to step through the Edit menus of all blocks in the preset (top-to-bottom, left-to-right)


  • Press EDIT after storing a preset to go right back to where you were
  • If you navigate anywhere from the Home page, EXIT will return you to the first screen of that page


  • Press TEMPO to open the Controllers menu


  • Press ENTER to randomize

Switch presets


To switch presets:

  • Value wheel or NAV right/left button
  • Onboard switch
  • External switch
  • FC controller
  • MIDI
  • Editor

More about Presets

Switch scenes


To switch scenes:

  • NAV buttons or soft knob
  • Onboard switch
  • External switch
  • FC controller
  • MIDI
  • Editor

More about Scenes

Switch channels


To switch channels:

  • Soft knob
  • Onboard switch
  • External switch
  • FC controller
  • MIDI
  • Editor

Read this: Channels

Switch layouts


Layouts on the FM3 are the same as on the FC controllers.

The FM3 provides 8 layouts plus a Master Layout. Additionally, the FM3 support Views (shifts focus within a layout)

Read this: Layouts

Control Switches


Read this: Modifiers, Controllers and Control Switches