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The Axe-Fx UltraTM contains two dual-voice monophonic synthesizers. These are classic oscillator-based synthesizers and can be used to do synth leads with your guitar or other instrument input. Alternatively, they can be controlled manually.


Each synth has two voices with the following parameters:

  • TYPE - Selects the type of waveform. Sine and triangle are the smoothest while the square and ramp types are more “buzzy”. Available types are: sine, square, triangle, sawtooth up, sawtooth down, random, pink noise and white noise.
  • TRACK - Selects the type of input tracking. OFF allows the frequency and level to be set manually via the FREQ and LEVEL controls. ENV ONLY selects the level to be controlled by the envelope of the input with the frequency set manually. PITCH+ENV selects the frequency and level to be controlled by the pitch and envelope of the input.
  • FREQ - If input tracking is set to OFF or ENV ONLY this paramter sets the oscillator frequency.
  • SHIFT - Shifts the frequency of the oscillator up or down in semitone steps. The oscillator can be shifted +/- 24 semitones.
  • TUNE - Detunes the oscillator slightly. The oscillator can be detuned +/- 50 cents.
  • DUTY - When using the TRIANGLE or SQUARE waveforms this parameter controls the duty cycle of the waveform.
  • LEVEL - Controls the output level of the oscillator.
  • PAN - Controls the panning of the oscillator.
  • FILTER - Sets the cutoff frequency of a low-pass filter after the oscillator.
  • Q - Sets the Q of the post-oscillator filter.
  • ATTACK - Sets the attack time of the envelope follower on the input.


If the synth sounds too sterile, add an amp and/or a cab afterwards, or try to run it through a drive block (e.g. Tape drive).