Always consult the Owners Manuals first


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Official product information

Fractal Audio website.

Owner's Manual

Owner's Manual.

AX8 wiki

Relevant wiki pages.

AX8 rigs


About the AX8

The AX8 is an all-in-one floor version of the Axe-Fx II, designed for the gigging musician. It provides Quantum amp modeling and UltraRes speaker cab sims, plus hundreds of effects and the familiar 4x12 grid, with the same quality as the Axe-Fx II. It differs from the Axe-Fx in that it offers only one instance per preset of amp, cab and some effects blocks (e.g. Reverb, Flanger, etc.) Also, certain esoteric effects found on the Axe-Fx are not included in the AX8 (Vocoder, Megatap, etc.) It has multiple outputs offering Humbuster technology, S/PDIF out and an effects loop.

  • "It is not an Axe-Fx. It won't be able to do two amps or two cabs. It won't have things like the Vocoder and other esoteric blocks. It's a stripped down floor version at an aggressive price.
  • It will have G3 modeling and user IR slots. It has two dual-core DSPs, one for amp modeling the other for effects. These DSPs are slower than the ones in the Axe-Fx so it won't be able to do two instance of amps.
  • There will be block compatibility between the Axe-Fx and the AX8 meaning you can copy blocks from your Axe-Fx presets into the AX8.
  • It has USB, XLR outs for FOH, 1/4" outputs for local monitoring and an FX loop. Four expression pedal inputs. AC powered, no wall-wart." (source)
"When I designed the AX8 I designed a product based on my 25 years playing as a pro and what I used 99% of the time during a gig. Even with the Axe-Fx II 99% of the time I dial up an amp, a cab and a few effects. What I care about most is a great tone. The Axe-Fx amp modeling algorithms are the best in the world. I wanted to design something portable and affordable enough to get those algorithms into the hands of a lot more players." source
"The DSPs used in the Axe-Fx are far too costly and require exotic cooling that is not suitable for a floor application. The AX8 covers the needs of 99% of performing guitar players." source
"The AX8 is not "way more powerful" than the FX8. The AX8 has one additional DSP that is DEDICATED to amp modeling. If you don't use the amp modeling the AX8 has the same power as the FX8. The AX8 will not work as well as the FX8 in 4CM. It is not designed for that. It will do 4CM, as will most digital processors but the FX8 is the only processor of which I'm aware that is truly optimized for 4CM. That optimization requires a lot of expensive circuitry. The op-amps used are very expensive and there's dozens of them just to support the 4CM stuff. Add to that relays for true bypass, metal film capacitors, etc., etc., and you end up with an expensive design. The FX8 and AX8 are built on the same code base. There is a single folder that is used to build the common elements for both products. Enhancements to one automatically enhance the other. All this work we've been doing for the AX8 will improve the FX8. The AX8 will be much more popular than the FX8. That should be obvious. Most people want the amp modeling. If you don't care about the amp modeling then the FX8 is the better product and the whole reason for having two different products." source



More specifications in the Owner's Manual.

(about memory in AX8) "More than will ever be used." source
"Each pedal jack support pedals or switches." source
"The AX8 was built to a price point with quality of sound the primary consideration. It's primary use is as a live performance product. A color LCD and USB audio were not deemed pertinent for the intended application. Had those been included the price would be much higher than $1399." source
"Unbalanced to monitors, XLRs to mains. Or use FX Send and echo to the send. Same as an Axe-Fx." source
(can I use the USB to send and receive midi for switching from a computer?) "Yes." source

Manufacturing details

Originally the AX8 made in the USA. Manufacturing has been shifted to China.

"Both the AX8 and FX8 are made in the USA." source
"The AX-8 and FX-8 are 100% made in China." source
"The AX8 isn't exactly featherweight either though. It has a heavy steel chassis and aluminum end-caps. It's pretty heavy but very durable." source
"Final test, programming and QC will still be done in the US. We test and inspect every unit. We do not do random sampling. Every single unit is put through a full functional test and inspection. A second QC operation is then performed prior to shipping. Costs more but results in less returns due to defects." source
"Our warehouse, shipping center, and engineering lab are in Plaistow NH. The real heart of the AX8—the firmware and all the software, are made in America. The design and mechanical are done here too. The unit is assembled in China using components sourced globally sourced components. In the context of such questions I always point out how the computers we're chatting through are made—who knows where—but in a global economy, what matters in the context of your such a question is that Fractal Audio Systems is an American company, with high quality overseas partners who handle certain physical aspects of getting the product made." source

Comparing the AX8 to the Axe-Fx II and FX8

"The XL+ front input circuit is identical to the AX-8 except the AX-8 doesn't have the variable impedance circuitry." source
"AX8 and Axe-Fx II share the same code base so any updates to the Axe-Fx II apply to the AX8." source
"Dimensions and weight are the same as the FX8." source
"Same grid as Axe-Fx II. 512 user cab slots, 512 preset slots. Same factory amps and cabs as Axe-Fx II. Same high-quality, low-noise design as Axe-Fx II XL+. True differential I/O to the converters, not the single-ended stuff used in consumer-grade gear. Silent Switch technology from the MFC-101 Mark III. Humbuster I/Os. Most importantly it has Quantum and the "Fractal Sound". source
"The AX8 and FX8 uses the same converters (CS4272-CZZ) and op-amps. The circuit design in the FX8 is necessarily much more complex to support true-bypass switching (without pops and clicks) and to optimize the outputs for use in 4CM. The AX8 removes the dedicated true bypass switching circuitry and simplifies the output design to save money. The cost savings is used towards an extra DSP." source
"Layout grid which is just like the Axe-Fx II." source
"The AX-8 is not an Axe-Fx II on the floor. If it was it would cost a heck of a lot more than it does. It uses the exact same modeling code as the Axe-Fx II. The overwhelming majority of people love the AX-8 and understand its place in the Fractal Audio model line-up. Putting an Axe-Fx II on the floor wasn't feasible due to the DSPs used in the Axe-Fx II requiring active cooling and being very expensive. The AX-8 was designed as a lower cost, simpler product that would address the needs of 99% of users. Power users will want an Axe-Fx II which is still the best modeler in the world." source
"The AX8 has Humbuster outputs as well. It will do 4CM but probably not as good as an FX8 which was purpose-designed for 4CM. If we used the output topology of the FX8 in the AX8 the AX8 would cost a LOT more." source
"The SHARC processors in the AX-8 support 40-bit word lengths and we use them just as we do in the Axe-Fx II." source
"The AX8 uses the same converters as the Axe-Fx II. We put the money where people can't see it but where they can hear it." source
"The Axe-Fx II can run multiple instances of amps, cabs and most effects. The AX8 cannot. The processors used in the AX8 are not nearly as powerful as the processors used in the Axe-Fx II. They are also significantly less expensive." source
"It does not have the vocoder and several of the other more esoteric effects. It does have the looper, synth and all the bread-and-butter effects. And it has the beautiful high-quality reverb from the Axe-Fx and FX8 (because I'm a reverb junkie). Most importantly, though, it sounds like an Axe-Fx." source
"They are very cool. They're not an Axe-Fx but they're close. Same amp and cab modeling. Stripped down effects section. Two 450 MHz DSPs; one for amp modeling the other for effects/housekeeping. Uses the same silent switch technology as the MFC-101 Mark III and FX8. Switches are assignable per patch via our new "Switch Assign Matrix" feature." source
"It's pretty much "Axe-Fx Lite". All the advanced parameters are available in the amp block, you access them via the traditional edit menu. The dedicated Bass, Mid, etc. knobs can be accessed at any time. And it sounds like an Axe-Fx, so there's that." source
"The AX8 was not designed for use with Global Block." source

Processing and latency

(Does the cab/mic/ir use the fx dsp or share the amp dsp?) "Neither really. They are done in an a separate accelerator so they have minimal CPU loading. An accelerator is a DSP unit dedicated to performing a defined task. In this case it performs convolution. The difference is that a "DSP" as we commonly call them is really just a microcomputer optimized for Digital Signal Processing. The term DSP most correctly refers to any device that does signal processing using numerical computations. That device can be an FPGA, ASIC or fixed hardware unit. In the AX8 it is a convolution processor." source
"The AX8 has two ADSP-21469s and two microcontrollers. It will only do one amp model at a time. Our amp modeling algorithms use up the entirety of one DSP. The second DSP is running at over 90% utilization. That's how detailed our algorithms are." source
"The TigerSHARC architecture is vastly superior to the SHARC, and it's a shame it has been discontinued. In our tests a TigerSHARC performs about 50% faster clock-for-clock. Then factor in the higher clock speed and it's about twice as fast. See here for independent benchmarks: The newest SHARCs are the same as the 213xx except they have the FIR accelerator. As one can see a TigerSHARC (Axe-Fx's use the ADSP-TS201S) is about twice as fast. (...) The TigerSHARC has a more modern core and much better architecture (larger register file, wider buses, better DAG units, etc). It can do six floating point operations per clock. In practice this is two multiplies, two adds and two store/fetch instructions. This means a 4096 point IR only requires 2048 clock cycles. Secondly the TigerSHARC has a much wider bus than a SHARC. The TigerSHARC has a 512 bit bus whereas a SHARC has a 128 bit bus. The TS can move data around much faster and pipeline stalls due to bus contention are far less frequent. It can load or store eight words in a single clock cycle whereas a SHARC is hard pressed to do two. The TS also has a LOT more on-chip memory. A TS has 24 Mbits of on-chip memory compared to 5 Mbits for the best SHARC. This means more code/data in fast memory and less stalls waiting for data access. Also the TS has a superior cache unit which caches both instructions and data, as opposed to instructions only on a SHARC. There are numerous other improvements as well including better DMA engine, better interrupt handling, vastly superior 40-bit floating point support (which we use for amp modeling), etc. Having written hundreds of thousands of lines of code for both (including coding the SHARC's FIR accelerator) my experience is that the TS is a much better chip but it is much more expensive. We moved to SHARCs for our floor processors for a variety of reasons but performance was definitely not one of them. The FIR accelerator is nice and all but it only applies to cab modeling which is a small percentage of a typical preset. On an Axe-Fx II a stereo Hi-Res cab block only uses 11% of the DSP. On an AX-8 it's still a couple percent as the accelerator doesn't handle everything needed in the block. So the net savings is less than 10%. The rest of the effects then run about twice as fast which means almost twice as many effects per preset on an Axe-Fx compared to an AX-8. While "all about the code" has some merit, in reality it's "all about a lot of things" including the architecture and clock speed. Algorithm complexity is also very important and it becomes diminishing returns (i.e. it takes twice as much CPU to improve the sound quality 10%). If it were just about the code everyone would still be using the original 33 MHz SHARCs. The TigerSHARC enjoyed a long run as the best DSP on the market but, alas, all good things must come to an end. The good news is that Atomic, Fractal and Line6 are all using the same DSP family in their respective floor products so it's highly unlikely Analog Devices will discontinue them and there are now more choices for the consumer." source
"There will be no pay-to-play stuff. All amp models from the Axe-Fx II will be included as well as all the Drives, etc." source
"The latency is the same as the Axe-Fx II."
"Latency is fixed and does not change with CPU usage. It's less than 2 ms."
(Can the Ax8 run a stereo UR cab and the AxII HD reverb?) "Yes, with ease." source
(How many effects can you run at a time?) "Depends on the effects but typically 8-10 in addition to amp and cab. The amp and cab block use very little of the main DSP. The amp runs in a dedicated DSP and the cab processing runs in an accelerator. Therefore most of the main DSP is available for effects." source
"You can have more than 8 effects in a preset. For example, you could have 12 effects in a preset. You then assign which of those effects you want to be able to switch on and off via the footswitches." source
"Our modeling is very detailed and whenever the amp model changes the "virtual circuit" needs to be reconfigured. We can switch quickly but often this causes clicks and pops due to the reconfiguration. So the amp block needs to run silently for a bit so things will settle. Then we unmute the block. This mute period is what you are hearing. Most other products just use a fixed algorithm and change the input/output EQ and gain. With this type of algorithm you can switch quickly without clicks and pops but, of course, you don't get the realism and detail." source

Buttons, knobs, switches

Navigate and operate

Operating requires the use of buttons (PAGE, ENTER, EXIT etc.), footswitches and the following knobs:

The AX8 provides 8 physical amp controls: Drive, Bass, Mid, Treble, Presence, Depth, Master, Level.

Assign effects and functions to switches

The main screen on the AX8 is the Footswitch Page (FS), which displays 8 switchable blocks, assigned to effects. You can also assign other functions, aka "footswitch blocks". You assign an effect or function by selecting a footswitch, turning the VALUE knob and pressing ENTER. Select from:

IMPORTANT: before you can assign an effect to a footswitch, you need to add the effect to the grid on the Layout page first. Use VALUE to select the effect and press ENTER. To access the Layout grid from the FS page, press Page. To leave the grid, press SHIFT + PAGE or EXIT (depending on the EXIT setting in the Global menu).

Footswitch assignments do not affect effect blocks or their order.

You can turn a footswitch into a "global" footswitch, forcing its assigned function to be the same across all presets. Footswitches are designated as either "Global" or "Per-Preset" using the Global Footswitch (“GBL FS”) page in the GLOBAL Menu.

You can assign multiple footswitches to the same effect block. This enables you to, for example, assign a latching AND a momentary switch to the same effect.

Assign the F-switches

In Global > F-switch you can assign functions to the 3 switches at the right. Each switch supports a Press action and a Press-and-Hold action. Select from:

Using the editor simplifies the assignment of footswitches.



LAYOUT page:

Within a block's EDIT menu:

AMP GEQ page:


Switch presets

There are several ways to switch presets:

The AX8 does not provide a "global preset" feature. Workaround:

  1. Set one of the 1-8 switches to "Global latching" (Global menu).
  2. Assign that switch to the preferred preset in the bank (FS page).
  3. Now press that switch at any time to immediately recall the preferred preset.
  4. To make it work across multiple banks, copy and paste the preferred preset to the same position in those banks.

The parameter "Display Large Preset" in the Global menu enables or disables the display of preset titles in a large font size, and the number of seconds (or "always") that you want it displayed.

Bank Limit

The Bank Limit parameter in the Global menu simplifies preset and bank selection during a live performance. It limits the available banks you can access through the footswitches with an UPPER and LOWER limit. For example, you can limit your device to footswitch access to banks 1 through 4 for one gig.

Bank Limit is available in the Global menu.

There are three parameters:

Switch scenes

There are several ways to switch between scenes:

In the Global menu you can specify the default scene for all presets. This includes the possibility to specify: Current scene. This means that when switching presets, the device will stick to the current scene number. You can also set the preferred scene per preset.

Switch an effect block between X/Y

Read this: X/Y switching.

Press & Hold interval

You can specify how long you need to press and hold a switch to engage its “hold switch” functionality in the Global menu.

You can also disable press-and-hold, see below.

Up-stroke versus down-stroke switching

By default the unit engages or bypasses an effect or function when "releasing" a switch. This is necessary for the "press-and-hold" functionality.

You can make the switch activate immediately when pushed:

With press-and-hold disabled, operating the unit feels faster. But you can no longer hold a switch to switch an effect between X/Y.

Also, when you set the “HOLD” function of any F-switch to “NONE”, its TAP function switch will execute on the switch down-stroke instead of the up-stroke.

Latching and momentary onboard footswitches

Momentary switches do not “latch” when you step on them. They engage while your foot is down on the switch, and stop when you lift it up. Any of the numbered footswitches may be designated as MOMENTARY. This can be done either GLOBALLY (Global menu) or PER-PRESET (Config page).

If a momentary footswitch is used to BYPASS/ENGAGE effects, the effect state will be reversed by the action of the switch. A block that is saved as ENABLED will by momentarily bypassed. A block that is saved as BYPASSED will by momentarily enabled. The same is true for a momentary footswitch assigned to SCENE 1/2 Toggle: depending on whether Scene 1 or Scene 2 is selected, the switch will momentarily toggle to the other.

The settings on the CONFIG > FS MODE page have no effect for a footswitch if it is set to one of the GLOBAL options on the GBL FS page.

The AX8 lets you assign multiple footswitches to the same effect block. This enables you to, for example, assign a latching and a momentary switch to the same effect.

Control Switches

You can assign footswitches 1-8 to operate as CONTROL SWITCHES. This enables you, for example, to create a BOOST footswitch (Volume modifier), a WHAMMY effect (Pitch Block: Control modifier), a single footswitch that toggles two or more effects on or off in unison (BYPASS MODE modifiers) and more.

CONTROL SWITCH 1 and 2 are footswitch blocks which can be assigned globally or per-preset, like any other footswitch block from the main Footswitch (“FS”) page.

To set up a Control Switch footswitch:

  1. On the Footswitch (“FS”) page, use the NAV and A knobs to assign CS1 or CS2 to footswitch 1 – 8.
  2. Add a modifier to the desired effect parameter, setting “CTRL SW1” or "CTRL SW2” as the source.
  3. Adjust the modifier to work as desired.

Now, when you step on the footswitch, the modifier will change the value of the assigned parameter.

Coupled with the “Momentary Footswitch” options, Control Switches are quite powerful.

The initial value of each Control Switch is saved per scene. The initial values are set on the Control Switches (“CTRL SW”) page of the CONTROLLERS area of the CONFIG page.

To set initial values for a Control Switch:

  1. From the main FOOTSWITCH (“FS”) page of the AX8, page right to the CONFIG page.
  2. Select the CONTROLLERS option and press <ENTER>.
  3. Page to the CONTROL SWITCH (“CTRL SW”) page.
  4. Set the initial value of each switch for each scene to either “ON” or “OFF”.

Forum discussion about the use of Control Switches.

"The switches are multi-function. They operate as preset, scene, looper or bypass switches. There are four expression pedal inputs. There is a stereo effects loop. The dedicated knobs control only those parameters for which they are indicated. There are five soft knobs under the display that are used for adjusting other parameters." source
"Footswitches are freely assignable. There is a footswitch assign menu." source
"The AX8 uses assignable switches. So rather than a dedicated Looper control mode, you can choose which Looper controls you want on the assignment page. Most people don't use all the Looper controls so this system is more flexible." source
"The eight main footswitches are assignable per preset. A screen shows you at glance what each switch controls. The function switches are configurable globally." source

Tips and tricks

Improving readability of preset list

Improve the readability of the preset titles in the Single/Sticky Preset screen, by adding spaces to each consecutive preset name:

Then start over again.

Make sure to not add too many spaces, because it will roll off the title off the screen when recalling that preset.


Mounting the AX8 on a pedalboard

You can remove the rubber feet of the AX8 to mount it on a pedalboard with Velcro. BUT: do not use the same screws again, use substitute screws. You need M3.5 x 6mm flat head screws. source

Where to find these substitute screws in Europe.

FAQ (from the Owner's Manual)

Q: How do I upgrade the firmware of my AX8?
A: Use Fractal-Bot, available here.

Q: Can I load my presets from the Axe-Fx or FX8 into the AX8?
A: No, but you can transfer individual blocks using the editor software for each product.

Q: Why does my AX8 keep changing to the Edit menu of one of my effects?
A: This is normal while AX8-Edit is running. The pause button in the upper left corner of the program is designed to stop this so you can edit the unit from its top panel without interference from the editor.

Q: The effect on/off footswitches seem a little sluggish. Why is that?
A: Because it supports Press-and-Hold functions, the AX8 activates effects on the upstoke of the footswitch instead of the down-stroke. You can change this behavior.

Q: I’m hearing click and pops.
A: Are you clipping the AX8 outputs? Could it be a bad cable in your rig? Excessive CPU usage may also be to blame. Check the STATUS page in the UTILITY menu under SETUP. Is the CPU meter in the mid 90s or higher? If so, you’ve overloaded the current preset. Try removing one block.

Q: Where can I learn more about all the many parameters for all of these effect blocks?
A: We’re currently working on a universal Effect Parameters Guide for all Fractal Audio Systems products. Meanwhile, the Axe-Fx II manual has most of the answers you might need. Find it here.

Q: One my effects has totally stopped working!
A: Relax. When a tweaked effect overloads the CPU, the AX8 will disable one effect block. This block will be quickly blink on the grid and footswitch page, and its Edit Menu will show “DISABLED”. Reduce CPU load and the effect should automatically re-enable itself.

Q: My expression pedal isn’t working. What should I do?
A: Expression pedals need to be calibrated, mapped to a controller, and assigned to a parameter. Are you using a TRS cable? Is it connected to the right jack on the AX8? Is it actually an expression pedal? Did you set up a modifier?

Q: My AX8 won’t start up correctly.
A: One problem that may cause this is a bad preset. To get around this issue, reboot the AX8, but as soon as the “Splash Screen” is displayed, tap ENTER to load an empty, initialized preset. If this solves your trouble, you’ll need to find and overwrite the problem preset, which may be as easy as pressing STORE, ENTER, ENTER after performing this special startup routine.

Q: One or more of my presets produces no sound. What gives?
A: This might be any one (or several) of a number of things: Is your rig working correctly? Most of the time, the problem is a faulty or disconnected cable! Have you double-checked to ensure that you have a complete path from the input to the output? Is there a MODIFIER assigned to a volume or level control while the pedal or external switch is not present? You may also need to change the Initial Value for an external controller from 0% to 100%. Does the preset require a USER CAB which is not loaded? Try changing the CAB block to a Factory cab.

Q: Can I use a computer or external MIDI controller to operate the AX8?
A: Yes. The AX8 has a rich MIDI spec which allows it to be remote controlled.

Q: What is “FRFR”?
A: FRFR stands for “full-range, flat response.” This acronym is used to describe a “neutral” speaker or speaker system that is designed to reproduce the entire audible spectrum of 20 Hz – 20kHz without emphasis or de-emphasis. Examples of FRFR systems would include studio monitors and properly designed PA systems or components. Many manufacturers are also now offering FRFR systems designed specifically for direct guitar applications.

Q: Why all the technical terminology? Can’t every control just go from 1 to 10?
A: Only the precise terminology of audio engineering allows the very diverse communities of casual and professional players, producers, engineers, and others, to get the most from the AX8. If you’d like to brush up on Hertz, PicoFarads, milliseconds, etc., you can easily find a good glossary of pro audio terms online, or refer to the appendix of the Axe-Fx II manual.

Q: Why would I place a certain effect BEFORE or AFTER the Amp and Cab?
A: Sonically speaking, the main reason to care about effect placement is that a given effect will sound different when placed before or after distortion. How does this difference sound? If you’ve ever switched the sequence of traditional DRIVE and WAH pedals, you’ve heard an excellent example. In the case of wah before overdrive, the resonant filter of the wah “excites” the overdrive in a cool way while still retaining a natural overall tone. When the wah follows distortion, you might hear a more dramatic filtered sweep—with heavy distortion it can get almost synth-like—which might be considered less “classic.” It’s not surprising then that Wah would traditionally be a run as a “pre” effect between guitar and amp. The amp’s distortion follows the wah effect. Many other effects fall in this same category. A different example is found in overdrive with reverb and delay. In the natural world, reverb and echo occur because of open spaces around your guitar amp – like a club or concert hall. These effects would therefore NOT be heard before a distorted amp, but after it. Recording studios often add these kinds of effects at the console—after the mic has picked up the distorted sound from the guitar amp. If you wanted to simulate this natural sounding reverb or delay these effects would likely be run “post.” This is not to say that delay or reverb before distortion is a “no-no.” Many “legendary” tones came from echo units in front of an amp—but this effect is very different from “post” delay not only tonally, but also in terms of dynamics. The good news is that the AX8 allows you to experiment easily and find what combinations of pre- and post-effects work best for you. Creativity begins where conformity ends

Q: Why do I hear a pop or a gap when changing certain X/Y block types?
A: When you change X/Y, the AX8 may need to completely reprogram a block for its new function. In some cases, this is sonically transparent. In other cases, this may mean making changes inside the block which cause a small pop or gap. One option for DRIVE blocks that makes this completely avoidable is to use two different blocks instead of one block with X/Y Switching.

Q: My AX8 stopped working during or after a firmware update. How can I recover it?
A: The AX8 has a built in recovery routine. Power the unit off. Hold down the SHIFT button, and then power the unit on. Hold the button for about 1 second beyond the power up, and then release. Turn the page to the FIRMWARE screen and you will be able to install firmware using Fractal-Bot.

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