Axe-Fx II FAQ

INTRODUCTION

This is a FAQ for the Fractal Audio Axe-Fx (AFXII) II. I copied content from forum messages by Fractal Audio, Fractal forum administrators/moderators and other experienced users (Matman, Javajunkie, Bakerman, Jay Mitchell, Scott Peterson, Don Petersen, Rex, GuitarDojo etc.) and added missing stuff.

This FAQ is not officially supported by Fractal Audio.

Note: THIS FAQ IS UNDER CONSTRUCTION! Its content is being migrated to a new Wiki. The official Axe-Fx II manual, created by Matman, is available now.

Alexander van Engelen (Yek)

CONNECTING THE INPUT / INSTRUMENTS

How do I connect my guitar

1. The front panel input uses a proprietary circuit and dedicated A/D converter for low noise. Always use the front input for guitar, whether wired or wireless. Source
2. The front input does not disable the rear input (different from Standard/Ultra). Use the menu to select either the front or the rear for Input 1. You can leave everything plugged in. Source
3. The front input impedance is 1 Mohm, or less if Input Impdance is adjusted.
4. All rear analog inputs are balanced like the onboard XLR outputs. The inputs detect whether the incoming signal is balanced or not.
5. Do not use speaker cable to connect to the 1/4" inputs.

How do I connect a wireless receiver

The same way as with your guitar: to the front input, to take advantage of the front input's "special sauce" for noise reduction. The rear inputs (both 1 and 2) operate at line level, the front input operates at instrument level.

How do I set the input level(s)

Instead of knobs on the front panel, there are soft Input knobs in the I/O menu. The input levels are controlled via digitally-controlled potentiometer. These work globally, not per preset. The setting doesn't affect the input gain of the Amp and Drive blocks. Source1 Source2

Can I connect a music player

Yes, connect the player to the USB slot. The signal will be mixed into the output signal. Adjust the volume on the player. Source

CONNECTING THE OUTPUT / AMPLIFYING

How do I use it with FR amplification

(tube / ss poweramp)

How do I use it with my own preamp or amplifier (4CM)

The AFXII supports unity gain when settings things up for 4CM: Four Cable Method. To obtain unity gain turn both Output knobs on the front panel fully up. Source

How do I set up two separate output feeds

1. FOH
2. FR
3. speaker cabinet

How do I set the output levels and avoid clipping

1. The XLR outputs are line-level. Source

How does it obtain unity gain

The AFXII has digitally controlled potentiometers before and after the A/D and D/A converters. Therefore it knows what the input and output gains are. It compensates for these gains in the digital path. This allows "unity gain processing". If you set the Output Level knob to maximum you will get out what you put in (assuming the blocks have no gain). So if you were to make a preset with shunts from input to output and you put a 1V signal into the unit you would get 1V out. Source

How do the HumBuster outputs work

1. The 1/4" outputs have a "remote ground sense" feature. You take a TRS cable and on one end you put a TRS plug and on the other end you put a regular TS plug. On the TS end you tie the ring conductor to ground. Plug the TRS end into the Axe-Fx II. The ground noise of the attached equipment is sensed and added to the output signal thereby cancelling the common-mode noise (hum). This is especially useful when doing the 4CM since that's when you usually get the worst ground loops. Source
2. Manual page ...

How do I adjust the headphones level

Use the Output 1 knob. Source

How do I mute the signal when using the Tuner

See Noise Gate.

CREATING AND EDITING PRESETS

How many presets can I use

384.

Can I load Standard and Ultra presets

No. Source1 Source2

How does the DSP load compare to the Ultra

A patch that uses 94% of the DSP on an Ultra will use around 70% on the AFXII. Source

How do I prevent overloading the DSPs

1. Manual page ...

How do I use the presets of other users

1. Manual page ...

Does it have a Compare function for presets or effect blocks

No(t) yet. Source Alternatively you can set up two presets, use the X/Y function or use Axe-Edit's Snapshot to compare.

How do I use the Quick Control knobs

1. You can use them to quickly scroll through presets instead of using the Value Wheel. Source
2. They can be assigned to any modifiable parameter per patch. Source
3. Or configure them to function as controllers. Source1 Source2

What's the DIR tab on the main preset screen for

It lists preset names and numbers for quick recall. Source

How does Input Impedance work

It is a parameter in the layout menu that affects a hardware switch. It can be set to automatic (detects the appropriate setting based on your first effect) or you can set it manually. Source Its range is 70k - 1Meg. Source The input impedance is selectable from a dozen or so values. It is done right at the instrument input using analog switches. Source It changes based on the amp model, however amps are always 1 Meg. If the first active effect is a Drive, for example, the impedance will change based on the Drive model. Source It can be saved per preset. Source The impedance feature will only have an audible effect if you are plugging your guitar directly in. It operates by loading down the guitar's pickups. If you have anything buffering the guitar then you won't be loading the pickups. Source

The amps are all 1Meg but if there's an active effect before the amp and it's default impedance is lower the input impedance will switch to that (if configured to "auto"). __________________

What are Global Blocks

1. An effect block can be saved as a Global Block. It then can be linked to from other presets, just like Global Amps. A change to the "master" will affect all linked blocks.
2. Manual page ...

How do I edit presets on the computer

Use Axe-Edit.

How do I make editing easier and faster

1. Manual page ...

How do I use settings from other presets

1. Manual page ...

How do I reset an effect to its defaults

1. Manual page ...

How do I insert more than 12 effects in a preset

1. Manual page ...

How do I add an effect to a preset

1. Manual page ...

What do I need to know about running an effect in mono or stereo

1. Manual page ...

What's the correct Bypass Mode for an effect

1. Manual page ...

How do I avoid output clipping

1. Manual page ...

How do I globally control the Bypass Mode of an effect block

1. Manual page ...

USING PRESETS / PLAYING

How fast does it switch between presets

About 20ms.

Does it support spillover of delay trails and reverb between presets

1. Yes, in the same way as the 1st-generation units.
2. Manual page ...

Can I adjust the levels of presets during play

1. Manual page ...

How do I adjust effect settings globally to the room

1. Manual page ...

How does the X/Y function work

1. You can set up certain effect blocks to switch between two sets of parameters. For example, with Amp blocks you can have 4 configured amps per preset, of which two can be active. Then use the X/Y knob on the front panel, or an IA switch (toggle) on a MIDI foot controller, to switch between the sets. This essentially doubles the number of those blocks within a preset. X and Y can be the same type of effect, say a RAT drive, but with different parameters. There's no transition between the two. Switching occurs at block level using a MID CC, not on preset level. Source1 Source2 Source3 Source4 Source5 Source6
2. Cliff: "The idea behind X/Y is that people often have multiple distortion/chorus/delay/etc. pedals on their board but they rarely have more than one on at a time. So rather than creating more instances of effects, which sucks up CPU, have each instance capable of more than one sound." Source
3. X/Y switching is nearly instantaneous. Source
4. X/Y doesn't support spillover. Source
5. On the MFC-101 X is green, Y is Red. Source
6. The X and Y buttons also double as user-definable Quick-Jump keys, which can be set to open the EDIT menus of any 2 blocks without going through the grid.
7. Values 0-63 for the CC select Y, and 64-128 select X. Source
8. Manual page ...

AMP BLOCK

How many amp models can it hold

Lots. Source Each preset can have two Amp blocks. There's no impact on the DSP capacity because one of the two AFXII DSPs is devoted entirely to amp modeling. Each Amp block can also use the X/Y feature to switch between sets of parameters. The current state is indicated on the front panel display.

Can I rename the amp types

No. Source

How much DSP-capacity does an amp block require

One Amp block uses about 40%. One of the two DSPs is dedicated to Amp blocks. So you can run 2 of those. The other DSP is for other effects. Source

Does the amp modeling differ from Standard/Ultra

1. Yes. It's called G2 and Virtual Vaccuum Modeling modeling. See Fractal Audio website.
2. A part of it has been ported to Standard/Ultra firmware (firmware 11).
3. Cliff: "As you listen to clips from modelers what you start to recognize is a certain "stationary" aspect to the tone compared to the every-changing tonality of a tube amp. Another thing is finger response. With a good tube amp you can vary the tone quite a bit just by how you fret the note and attack it. Modelers tend to make every note sound the same. So I tested some hypotheses and came to the conclusion that it's because a real vacuum tube has a transfer function that is not static. The transfer function is dependent on time, frequency and amplitude. Where you really hear it is in the in-between regions where the tube is just starting to distort. At first I tried some dynamic transfer functions but that was a lesson in futility. So then I created the VVT stuff. In VVT there is an actual vacuum-tube replica in software. You enter the values of the resistors and capacitors on the grid, cathode, etc. and it behaves just like a tube complete with Miller effect, cathode memory, etc. The problem is that it requires an obscene amount of horsepower so the only solution was a dedicated DSP. The other big part of the G2 sound is the output transformer modeling. The OT distorts and as it distorts its inductance decreases which changes the bandwidth and loop characteristics." Source

How do I know which cab type to use with an amp

1. Wiki

Where is the 8-band EQ positioned in the Amp block

It's fixed in position at the very output. Source

What are Global Amps

Global Amps do not exist anymore. There are Global Blocks now.

Do amps still have negative presence

No. However for amps with no negative feedback (damp at 0) it turns into a Hicut parameter. Source

Can I split the preamp and poweramp

No.

Are all amp parameters assignable to MIDI controllers

No. Cliff stated it now has the ability to do that for all parameters so maybe down the road. Source1 Source2

How do I use Presence

1. The way Presence works is changed. It's now a traditional Presence control (0-10) for amps that have a Presence control. There's no default, so keep this in mind when changing amp types. Source For amps without Presence, it's changes into a Hi-Cut control.

How does Input Trim work

Changing the input trim doesn't affect the amount of distortion. This the whole idea. You set the trim to optimize the signal level into the converters. Internally the unit applies the inverse of the trim so that the signal into the grid is constant. In other words, if you put 1V into the input the input to the grid is 1V regardless of the trim setting. Source

What do I need to know about the advanced parameters

1. Saturation switch: it switches in a zener diode clipping stage right before the tone stack. This is the "Arrendondo Mod". Source
2. Warmth and Thump: these Standard/Ultra parameters haven been removed from the Amp block in the AFXII. Source

What about Standard/Ultra amp types that are not in the list (yet)

1. Cliff: "The amps I haven't ported yet are because I don't have the real amp yet. I could use theoretical values but I would rather not." Source
2. Javajunkie: "Plexi2 on Ultra = Plexi 1 w/ different bright cap val, xformer hi freq, and presence freq. I have the values written down. You can do the same with the Plexi normal on the II. From what I understand (and Cliff can correct if I am wrong) - Plexi 1 and 2 are the same models with different default values. Source
3. Cliff: "As for Eggie... It's just a Blues Jr. with no negative feedback." Source

CAB BLOCK

How many cab slots does it have

1. 70 factory (stock) cabs.
2. 50 user cab slot for external IRs.
3. Each Cab block can also use the X/Y feature to switch between sets of parameters. Source

Which new parameters are added to the cab block

Room Level, Room Size, Mic Spacing, Low Cut and High Cut. Source

What are 2048-point IRs good for

1. Cliff: "Depends on the cab. Certain cabs benefit more than others. I started out with 8192 but didn't hear any difference so couldn't justify wasting all that space and CPU. You can hear it with room mics but the room simulation sounds nearly identical. There are a couple reasons for 2048. Probably most important is that it allows 1024 in stereo mode. To be able to do stereo 1024 requires a 2048 convolution engine. Secondly, some IRs benefit from longer IRs. Better to have the ability and not need it than the converse." Source1 Source2
2. A stereo cab (LoRes) now uses two 1024 IRs (instead of 512 on Standard/Ultra). Source
3. Jay Mitchell's comments on 512-, 1024- and 2048-point IRs: Source1 and Source2 and Source3 and Source4.
4. It's no use converting 1024-point IRs to 2048 since they don't contain the necessary data. You need a WAV-file to convert to 2048. Use AlbertA's conversion utility to convert WAV files into 2048-point IRs.

Where do I find 3rd-party IRs

Sources for 3rd-party IRs:

• Ownhammer
• RedWirez

These companies create and sell high-quality IRs for Standard/Ultra as well as AFXII. You can load these IRs into the user cab slots using Axe-Edit. Some of their IRs are included with the AFXII as stock cabs.

Also included are IRs by Jay Mitchell.

Where is the Drive parameter in the cab block

This parameter has been removed from the Cab block in the AFXII. Instead, the Amp block has dynamic speaker modeling in the Amp block. Source

Does it have a cab type for acoustic guitar

No. But there's a thread on the forum that contains Fishman Aurex IRs (1024-point). And there's an IR available of an acoustic body that has been converted to 2048 points.

Can I rename cabs in the user cab slots

Yes, using Axe-Edit. The AFXII uses the name contained in the sysex data of the IR-file to show on its display with a maximum of 32 characters. Source1 Source2

Can I make it sound more like an amp in the room

1. Select a farfield cab type (not close-mic'd).
2. Set the Mic Type to none, to keep tone colorizing by the mic away.
3. Use the room simulation controls in the Cab block. These can be used with any IR. It's a special reverb algoritm.

Why are two cab blocks louder than a single one

Bakerman: "It depends on how you're panning. Assuming a mono signal sent to cabs: Stereo cab w/ Pan L and Pan R fully left & right will be the same output level as 2 mono cabs w/ balance L & R. If pans/balances are centered the 2 mono cabs will be 6 dB louder. Balance elsewhere would be between 0 and 6 dB louder, and balance doesn't correspond 1:1 to pan L/R for the same placement. Balances will need to be further toward -50 or 50. Source

What's the AIR parameter for

There's no AIR parameter anymore.

How do I know which cab type to use with an amp

See Wiki.

What are the factory (stock) cab types

See page 57 of the manual.

PEDALS, SWITCHES, FOOT CONTROLLERS

Can I use the Quick Control knobs as pedals

Yes. Source

What's the purpose of the Rj45 port

Use this to connect the MFC-101, instead of using a MIDI cable. It uses a regular CAT-5 network cable and a propietary protocol. This supports bidirectional communication and phantom power. Source

When using the CAT-5 cable a 9V adapter is no longer needed to provide phantom power. Source1 Source2

When switching off the AFXII, the MFC-101 also switches off. Source

All four pairs are used. The two normally unused pairs are used to carry power and ground. Source

Does it support a future MFC-101 expansion unit

Yes. Source

How many pedals can be connected directly

One.