NFM User Guide


NFM is an intuitive FM synthesiser with a streamlined interface. It works as an Audio Unit extension inside host applications such as GarageBand, Cubasis, Auria Pro, modstep and AUM.

User Interface

NFM interface consists of 2 views of controls titled Operators and FX & Output. The Operators view allows you to configure individual operators as well as the FM modulation matrix. The FX & Output view lets you further shape the sound.

Parameter Controls

  • Knob: Touch and drag your finger vertically to adjust the value.
  • Pop-up menu: Tap and choose an item from the popover.
  • XY Pad: This control allows you to control 2 parameters at the same time. Drag the main puck to adjust both X and Y parameter values simultaneously. To control them independent pdenetly use the dedicated handles.
  • Envelope: Envelope segment level, time and curve values can be adjusted independently with the dedicated handles. Level and curve values are adjusted by dragging corresponding handles vertically. Time values are adjusted by dragging the handles horizontally.
  • On/off switch: Tap the switch to toggle it.

Parameter Values and Numeric Pad

When adjusting a parameter the title of its control is replaced by the parameter value. In order to view the parameter value without adjusting it simply tap on its control or handle. The values can be set precisely using the built-in Numeric Pad. Simply tap on the value and the Numeric Pad will be presented.

Preset Selector

  • Preset Selector is always displaying the currently selected preset.
  • Tap it to browse and select presets from the popover.
  • From the popover you can swipe the preset name left to delete it. If you drag your finger left slowly you will be presented with options to rename or to delete the preset.
  • Tap the previous or next button to switch between presets.
  • Tap the Save button to save the current synth state as a new preset.

FM Algorithm

FM Algorithm's interface is inspired by Native Instrument's FM8 FM Matrix. It allows you to wire up modulators and carriers in any way you like. Every operator can be a modulator, a carrier, or both simultaneously. Each modulator can modulate any number of carriers. For example, operator C can modulate D, E and F and send feedback to A and B operators.

  • Tapping on an operator button (labeled A, B, C etc.) switches the active operator view.
  • The rest of the boxes indicate the modulation/feedback amount between the operators and can be adjusted by dragging you finger vertically.


NFM comes with 6 stereo operators, which can self feedback and be further modulated by the stereo LFO.

  • Output: Sends the output of the operator to the master output.
  • Self FB: The self feedback amount.
  • Pan: Pans the operator.
  • Mode: An operator has three oscillator modes: Ratio, Fixed and Noise. The first two sets the operator oscillator to a sinusoid wave. Noise produces shaped noise.
  • Coarse, Fine: They define frequency ratio between the note pitch and the operator oscillator frequency. For example, Coarse value of 2 will set the pitch of the oscillator an octave higher. Non-zero values of Fine parameter introduces inharmonicity. For chorus type effects, set Fine values closer to 0 or 1000.
  • Frequency: In Fixed mode you can set the oscillator frequency to a constant. The operator will ignore the note pitch.
  • Envelope: Modulates the oscillator amplitude. Enveloper is highly flexible with adjustable level, time and curve parameters.
  • Amp<LFO: Amount of modulation of the operator amplitude by the LFO.
  • Amp<Vel: Amount of modulation of the operator amplitude by note velocity.
  • Amp<Key: Amount of modulation of the operator amplitude by note key.
  • Time<Vel: Amount of modulation of the envelope segment time values by note velocity.

FM Drive

  • FM Drive: Adjusts FM Algorithm intensity.


  • Depth: Vibrato depth in semitones.
  • Rate: Vibrato rate.


  • Waveform: LFO shape. There are seven shapes to choose from.
  • Rate: LFO rate which can be tempo synced.
  • Depth: LFO Depth.
  • Phase: Left and right channel phase offset.
  • Sync: Toggles host tempo synchronisation.
  • Retrig: When it's on each note triggers its own LFO.


  • Distortion: Amount of analogue style distortion that's applied to each voice independently.


  • Time: Tempo synced delay time.
  • Filter: Filter cutoff for the delayed signal.
  • Feedback: Delayed signal feedback amount.
  • Mix: Delay wet/dry mix.

Pitch Envelope

  • Depth: Pitch envelope depth in semitones.
  • Envelope: Highly flexible pitch envelope with adjustable level, time and curve parameters. The pitch envelope is applied to all operators.


Stereo flanger's left and right channels are 90º out of phase.

  • XY Pad: Adjusts Flanger Delay and Feedback values.
  • Rate: Flanger rate.
  • FB Mode: Flanger has four feedback modes. Cross feedback sends the left channel output to the right channel and vice versa. In inverted feedback mode, both channel signals are inverted before they are fed back.
  • Mix: Flanger wet/dry mix.


  • Global output level.


  • Voices: Voice mode can be set to mono, legato or a number of polyphonic voices. Keep polyphonic voice count low to save on CPU resources.
  • Glide: The time it takes to glide from one note pitch to another.

CPU Performance

  • Decrease the number of polyphonic voices if not needed. For example, for bass or lead presets, mono or legato voice modes would be the most efficient.