instrument editor

The instrument editor is the most complex window within Efflux. It is here where you'll spend time shaping the exact sound of your instruments. Each instrument is a synthesizer. It is recommended you start out by entering a simple pattern (either a long sustained note or a generic melody) in the pattern editor and loop the pattern with the instrument editor open, or by using an attached MIDI hardware device to play back notes while adjusting the instruments parameters.

oscillator editor

Each synthesizer has up to three oscillators (you can think of an oscillator as a "voice" that "sings" the note you tell it to play) and you can toggle the editing window between them using tablist "A".

Each oscillator generates sound by synthesizing a waveform, which is displayed in window "B". By using selector "D", you can switch between a few preset waveforms such as sawtooth, triangle and square wave, each of these have a different characteristic sound.

For more shaping possibilities you can draw a custom waveform inside window "B" using the mouse / touch and directly hear the results during playback. This is how you can create your own unique tones!

Keep in mind that by default each instrument only has one oscillator (the first) activated, to activate the others, click on the oscillator number inside tablist "A" and activate the oscillator using selector "C".

tuning your oscillators

Using the controls in section "E", you can tune each oscillator individually. From top to bottom, the controls are:

Detune, Octave shift, Fine shift and Volume.

Detune allows you to... detune your oscillator. The center position doesn't apply any detuning, the most left applies a detuning of -50 cents while the most right applies a detuning of +50 cents.

You may wonder what the point is of moving your carefully selected notes out of tune, but this can be a powerful means to fatten your sound. Much like a choir or a string ensemble, where not every voice is exactly in tune in relation to the others. In reality there are slight pitch differences, making the combined sound wide and thick.


Octave shift tunes your oscillator up to 2 octaves down (by moving the control to the left) or up to 2 octaves up (moving the control to the right). The steps are single octave increments.

Fine shift allows you to tune your oscillator in semitone steps in the range from -7 (most left position) via 0 (center position) to +7 (most right position). This allows you to harmonize your oscillators, making it possible to play "chords" using nothing more than a single note input and multiple tuned oscillators.

Finally, volume allows you to set the level of the oscillator, allowing you to balance it against the other oscillators within the instrument.

controlling envelopes

In section "F" you can edit either the Amplitude or Pitch envelopes of the oscillator by switching between the available tabs.

Amplitude basically describes the loudness of the sound, Pitch describes the amount of pitch movement the sound will have. Both envelopes will change their value over the course of the notes lifetime.

Both amplitude and pitch envelopes are provided with four controls to shape the envelope behaviour: Attack, Decay, Sustain and Release.


  1. Attack is the total time it takes from the initial note start to reach its maximum level (e.g. fade in).
  2. Decay is the following fade out to the designated sustain level that occurs after the attack phase.
  3. Sustain describes the level of the sound between the decay and subsequent release phases.
  4. Release is the fade out phase in which the sound reaches a volume of 0. The release phase initiates after the note stops playing (e.g. "key" is released).

pitch envelope

Pitch envelopes also have a Range-parameter.

The range paramter sets the amount of pitch shift that is applied by the envelope.

This goes from -24 semitones (set slider knob left from center) to +24 semitones (right from center).

By adjusting the sustain phase of the envelope, the decay phase will restore the pitch back towards the original pitch center. Same for the release phase (requires a positive release in the amplitude section to be audible).

multi-timbral playback

When entering notes using either the pattern editor or a connected MIDI peripheral, you are basically describing an instruction for the instrument as a whole, though each oscillator will work independently from the others to synthesize the sound.

So if you have three different oscillators configured, each of the oscillators will play the requested note using their own tuning and envelope settings. The tuning is applied to the frequency of the requested note while the amplitude and pitch envelopes are applied to the generated sound.

As such it is possible to have an oscillator detuned 2 octaves that has a long attack time so it fades in, while another oscillator is tuned up 1 octave, sounds immediately due to a low attack time, but fades quickly due to a short decay envelope.

adjusting the filter

A filter can either increase or decrease the intensity of certain frequencies of the sound.

By using selector "A" you can toggle the filter on / off for the instrument. Controls "B" and "C" define its cutoff frequency and resonance. The cutoff describes a specific region within the sound where the filter will "focus" on. The type of filtering is determined by selector "D". There are plenty of variations like lowpass (filters out high frequency content), highpass (filters out low frequency content) etc.

The filters cutoff frequency can also be modulated using an LFO (Low Frequency Oscillator). You can toggle this oscillators waveform (or disabled state) using selector "C".

Finally you can control the oscillators speed and depth using controls "E". The maximum speed is 25 Hz.

repeats... eats... ts...

Another way to add expand the sound stage of your synth is by using delay, an effect that creates echo.

You can toggle the delay on/off using selector "A" and select the type using selector "B".

Slider "C" sets the delay time, which basically defines the time between the original sound and each of the repeats. The maximum time is 2 seconds.

Slider "D" sets the feedback level, basically determining the amount of repeats from 1 to an endless loop where the echoes will feed on themselves.

Slider "E" sets the frequency cutoff of the repeats, while slider "F" sets the offset of the echoes between the left and right stereo channel (maximum half second, move the slider left to offset the left channel, move the slider to the right to offset the right channel).