Always consult the Owners Manuals first.
Note: the wiki is currently being updated with information about the FM3.

Synth block

From Fractal Audio Wiki
Jump to: navigation, search

Available on which products

  • Axe-Fx III: 2 blocks
  • FM3: 1 block
  • Axe-Fx II: 2 blocks
  • AX8: 1 block
  • FX8: 1 block

Channels or X/Y switching

  • Axe-Fx III and FM3: 2 channels
  • Axe-Fx II: no
  • AX8: no
  • FX8: no

About the Synth

"The Synth block is a very simple monophonic synth. It doesn't compare to the polyphonic capabilities of something like the FTP and it can't control outboard MIDI synths." source

The Synth block requires monophonic input. This means that you have play REALLY clean. Always hit single notes and avoid overlapping notes.

Introduction video

CPU usage

The Synth has 3 voices. Turn off voices that you don't use to save CPU.


Parameter (per voice) Axe-Fx III / FM3 Axe-Fx II AX8 / FX8
Type yes
Track yes
Frequency yes
Shift yes
Tune yes
Duty Cycle yes
Pan yes
Filter Frequency yes
Filter Q yes
Attack yes
Level yes


Frequencies of musical notes=

Read this

Simple Sine tone

Set a single voice to Sine and turn off Tracking.

Warm up the Synth sound

To warm up the Synth, add a Drive block before or after it. Try the Rat model.

Fatten the Synth sound

To fatten the Synth, use at least two voices and detune them slightly. source

Drone note

  1. Turn off Voices 2 and 3.
  2. In voice 1 switch off Tracking and adjust pitch with the Frequency parameter.

Look up the frequencies of notes


  • Try the Sawtooth waveform.
  • Make the sound fatter by using two Synth voices set to the same frequency.
  • Make the sound less boring by adding a low-pass Filter with lfo-controlled Frequency.
  • Make the sound wider by adding a 100% wet Multi-Delay or Plex Delay set to Detune.
  • Change the pitch of the drone note, by switching the Synth between channels or by using Scene controllers, attached to the Pitch or Shift parameter of the voice(s). Or just send the Synth into a Pitch block (changes the pitch of all voices).
  • Use the Sequencer controller to have the Synth block play lines.

Pink or white noise

The Synth block can generate white or pink noise.

White noise in Wikipedia

Pink noise in Wikipedia


Select a Square waveform and attach a LFO to the FREQ parameter of a single voice. Add a lot of reverb.

Calibration tone

"Set the synth block to a 1K sine wave at -12 dB. Turn OUTPUT 1 to the maximum level position." source
"There's actually a hidden calibration tone that is used during functional test. The Synth block is reference quality. I use it all the time to generate test tones. The output is spectrally purer than my $2000 Stanford Research Systems Synthesized Function Generator." source

More information

Look for synth presets created by Simeon, Swedish Chef and Admin M@. Search the forum and visit Axe-Change.

Wikipedia: Synthesizer