This is the wiki for products made by Fractal Audio Systems, maintained by members of the community.
Update: coming weeks the wiki will be updated with information about the new AMP4 amp modeler!
Difference between revisions of "AM4 amp modeler"
| Line 180: | Line 180: | ||
The four foot switches have colored indicators, but no scribble strips. | The four foot switches have colored indicators, but no scribble strips. | ||
| − | They support Tap and Hold functions (e.g., to switch channels). | + | They support Tap and Hold functions (e.g., to switch channels). Factory default is the so-called <q>Gig Mode</q>. You can customize the functions. |
=Remote control= | =Remote control= | ||
Revision as of 23:57, 24 November 2025
This page is under development!
Contents
- 1 References
- 2 Rig pictures
- 3 Design and development
- 4 Dimensions and weight
- 5 Processing and memory
- 6 Latency
- 7 Screen
- 8 Power
- 9 Firmware
- 10 Analog I/O
- 11 Digital I/O
- 12 Onboard switches
- 13 Remote control
- 14 User interface
- 15 Presets, scenes and channels
- 16 Effects
- 17 AM4-Edit software editor
- 18 Videos
References
Documentation:
Rig pictures
See “Owners show their AM4 boards” for a discussion how forum members are using their AM4 units.
Design and development
FRACTAL AUDIO QUOTES
[...] ...
Dimensions and weight
- Weight
- 3 lbs 9 oz (1.63 kg).
- Dimensions
- 10.00" x 6.31" (254mm x 160.3mm).
Processing and memory
FRACTAL AUDIO QUOTES
[...] ...
Latency
FRACTAL AUDIO QUOTES
[...] ...
See Latency for more information.
Screen
The display is a 480 x 272 high-contrast color LCD.
The AM4 does not have a touchscreen.
Power
The power connector is a 2.1mm barrel connector, with a negative center. The power-supply (9V DC, 1.5A) is included.
Do NOT use an AC supply. It WILL damage the unit.
The unit has a power button.
Firmware
The firmware is upgradeable, allowing adding new features and bug fixes.
You can download the latest official release from the AM4 downloads page.
Analog I/O
Input
Single mono input, 1/4" TS jack, max +20dBu (instrument level).
Input impedance is variable and is adjustable per preset.
The Input pad in SETUP is adjustable, with auto correction. The manual states that the AM4 is pre-configured for a typical guitar with hot pickups. If input clipping occurs, an ”IN CLIP“ warning is displayed and the Input Pad setting is temporarily increased.
OWNERS MANUAL
If the input of the AM4 clips persistently, the unit will automatically increase the Input Pad setting. When this occurs, the word “Auto” will appear next to the Input Pad value, for example: “12 dB (Auto)”, indicating that the pad was automatically increased to 12 dB. When you reboot the AM4, the automatic setting is cleared, and the last manually selected value is restored. If you want to make the automatic pad setting permanent, just turn the Input Pad knob one “click” to clear “Auto”.
As with the VP4, the input range of the AM4 is the same as an 18V pedal.
Output
1/4" TS L/R (mono/stereo), max +16dBu, 1 KOhm. Balanced. No Humbuster.
The output can be switched between mono and stereo in SETUP.
Similar to the VP4:
FRACTAL AUDIO QUOTES
[1] Humbuster is not necessary because it's DC powered and the chassis is floating. Hum occurs due to ground loops. If equipment is AC powered the chassis must be grounded by law. This introduces ground loops when using unbalanced connections. The correct solution is for everything to be balanced but the industry seems reluctant to embrace that.
4CM
4CM (Four Cable Method) is not supported.
Inserts
The AM4 does not provide a effects loop.
But it has a fixed insert point between the internal effects and the balanced outputs. Use these to connect external gear while preserving the clean, low-noise performance of the balanced outputs. The insert is fixed in hardware and cannot be repositioned or switched on/off.
It applies only to the main outs and is not heard on USB, SPDIF, or headphones.
For mono, use a standard patch cable. For stereo, use a TRS-to-dual-mono insert cable (tip = left, ring = right).
Headphones
The AM4 has a 3.5mm stereo headphones port.
Impedance is 35Ω. Recommended headphone impedance is less than 600Ω.
Digital I/O
Converters
24-bit, 48kHz (fixed).
Dynamic range is 114 dB, 20-20k frequency response.
USB
USB-C port for data and audio.
MIDI-over-USB is supported.
USB Audio 2.0 provides 4 channels (2x2) at 48kHz.
- OUT channels 1+2: processed output
- OUT channels 3+4 : unprocessed (copy of inputs)
- IN channels 1+2: send incoming USB Audio directly to outputs
- IN channels 3+4 : process incoming USB Audio and send to outputs
Windows computers require a software driver which is available on the AM4 Downloads page.
See USB for more information.
SPDIF
SPDIF can be used to digitally connect the AM4 to an VP4, FM3, FM9 or Axe-Fx, through RCA connectors, at 48kHz fixed sample rate.
A digital connection avoids the necessary A/D and D/A conversion and inherent latency that comes with analog-to-digital connections.
The SPDIF output of the AM4 always mirrors the signal at the analog outputs, except for the insert (see above).
Read Digital I/O and recording for more information.
Onboard switches
The four foot switches have colored indicators, but no scribble strips.
They support Tap and Hold functions (e.g., to switch channels). Factory default is the so-called Gig Mode
. You can customize the functions.
Remote control
MIDI
The unit has 3.5 mm (1/8”) MIDI IN and OUT ports. Adapters are available at Fractal Audio.
The Boss BMIDI-5-35 cable has been tested and works with the VP4 to connect to 5-pin MIDI gear.
The VP4 supports:
- Sending and receiving Program Changes (PC)
- Sending and receiving Control Changes (CC)
- MIDI-over-USB
- MIDI clock (receive only, currently)
- Software MIDI Thru
A table in the manual translates MIDI Program Changes to VP4 presets.
See MIDI for more information.
FRACTAL AUDIO QUOTES
[2] The VP4 supports MIDI over USB so it appears as MIDI ports in a DAW.
[3] Messages sent to the VP4 via MIDI-over-USB are not echoed to its MIDI OUT port, and messages received at its MIDI IN port are not passed to the computer via USB.
[4] The VP4 has fewer than 128 presets. MIDI Bank Select messages are not necessary to access all of its presets
Expression pedals and external switches
The unit supports two expression pedal connections (TRS, 10–100 kΩ max), or two single TS external switches (momentary or latching).
The unit does not provide FASLINK connections and therefore does not support connections to FC-6 and FC-12 foot controllers foot controllers.
Amp switching
The VP4 itself does not provide relays to switch amp channels, but it can connect through MIDI to a relay switcher to perform that duty.
Possible solutions include:
- MIDI Solutions Relay
- Suhr MicroMIDI Control
- Voodoo Lab Control Switcher
- Pirate MIDI CLiCK
- RJM Mini Amp Gizmo (no longer available from RJM but might be available used. The manual is currently available online.)
- EM
User interface
Compared to Fractal's modelers, the VP4 UI is simplified and streamlined.
Press + together to enter the “Mode Select” menu which allows you to select between Preset, Scene, Effects, and Tuner/Tempo. The mode determines what's displayed on the LCD, how the Select knob operates and what the switches do.
The factory default's “Gig Mode” configuration makes it easy to select presets, scenes, effects, channels, tuner and tap tempo. The startup mode can be set in Setup.
Press + together to enter Setup.
To edit parameters on the hardware, turn in Effect mode to highlight a block, press to edit the block, turn the corresponding knob to adjust the value, or to get to other pages.
When editing parameters on the hardware, press + together to enter “Expert Edit” mode. Expert Edit includes advanced parameters. Press to quit Expert Edit.
On the home page in FX Mode, select the desired block, hold the button, and turn to move.
FRACTAL AUDIO QUOTES
[5] Behind the scenes it's the architecture from the Axe-Fx III. There's still a grid and scenes and channels, etc. It's just that it's mostly hidden from the user and simplified.
Tip: If you don't need scene names, use the available space to indicate the specific effect types instead. Insert spaces to visually align them.
Presets, scenes and channels
The unit has 104 presets, supports four scenes per preset and four channels per effect block.
The presets are organized into 26 banks, each identified by a letter from A to Z. Within each bank, there are four presets, numbered 1 through 4. Presets can be configured for PRE, POST or 4CM. A list of factory presets is included at the the end of the Owners manual.
Switching between presets, scenes and channels is gapless.
VP4 presets and blocks are not compatible with Fractal Audio's other processors, nor vice versa.
The latest factory presets are available on the VP4 downloads page.
FRACTAL AUDIO QUOTES
[6] There are enough dissimilarities between the VP4 and the other products, that preset compatibility is not practical.
In response to the question:
Are saved blocks (no entire presets) transferable between VP4 and other Fractal products?:[7] No, many of the effects have changes that facilitate the simplified BASIC mode interface.
[8] [...] Block library entries are not cross compatible between VP4 and other products. Keeping the translator in sync across products/firmware versions is a can of worms, and b) the VP4 also has a few small differences in terms of how things are handled internally.
You can copy settings by hand and things will sound the same, but see the note in the purple box on p. 26 of the manual.
Effects
Available effects:
- Chorus block
- Compressor block
- Delay block
- Drive block
- Enhancer block
- Filter block
- Flanger block
- Formant block
- Gate/Expander block
- GEQ block
- IR Player block
- Megatap Delay block
- Multitap Delay block
- PEQ block
- Phaser block
- Pitch block
- Plex Delay block
- Resonator block
- Reverb block
- Ring Modulator block
- Rotary block
- Synth block
- Tremolo/Panner block
- Volume/Panner block
- Wah block
Note: there's also an IR player block.
There is a Noise gate at the input, before the four effects, and a 10-band EQ at the output of each preset, which are always on
.
The VP4 does not provide amp and cab modeling, but an IR Player has been added that has access to up to 256 onboard IRs. Also, compared to the FM3, there's no Multiband Compressor, Ten-Tap Delay, Mixer, Looper, Send/Return and Multiplexer.
Compared to the Axe-Fx, FM3 and FM9, the unit features:
- Additional tweaked types, such as Vibrato and single voice Pitch types
- Tweaked MIX Law for time-based effects
- Mode switch in some Drive types instead of multiple types (e.g. Timothy)
- Some renamed types
Effect blocks 2+3+4 can be routed in parallel with the previous effect.
The blocks support Fractal Audio's system of Modifiers and controllers.
FRACTAL AUDIO QUOTES
[9]
Can it run a Dual Detune, Reverb, Delay and a Plex Delay simultaneously, in a non-economy algo mode?
Yes[10]
Does the VP-4 support the improved FM9/Axe-FX III spring reverb algorithms?
Yes, it is totally up to date with Axe-Fx III in all effects.[11] The VP4 uses the newest pitch detector from the Axe-Fx III.
[12] The mix law in many blocks is different to suit the "all effects before the amp" crowd better.
[13] The sweetened mix law places a wider range of knob motion in the portion of the curve where the delay is quieter.
This replicates the way pedals that are designed for use in front of an amp work because the amp's compression reduces the difference between the quiet echoes and the louder dry signal.
AM4-Edit software editor
AM4-Edit is the editor for the AM4, with Fractal-Bot built-in.
You can download AM4-Edit, along with the Windows driver, firmware and factory presets updates, from the AM4 downloads page.
