[Nitrox 1.11]

Nitrox comprises five independent freely customizable envelope generators to be used as modulation sources just like ADSRs. The envelopes window can be opened with the following button in the main windows tool bar:

In contrast to the custom waves or wave shapers window all five envelopes are shown simultaneously. Only one of the envelopes has the focus at any time which is indicated by a grey rectangle around the envelope (ENV 1 in the image below). The focus is acquired by clicking anywhere into the envelope. The focus controls, to which envelope the tool bar buttons in the top right corner apply.

Each envelope has three parameters on the left hand side and a curve display on the right hand side.

Curve Display

In the curve display the envelope's curve can be freely customized. An envelope is definid by so-called handles which are depicted by either a square or a circle. The envlope curve itself is displayed in light blue. Furthermore, there are two so-called loop markers which are depicted in a darker shade of blue.

The curve display itself is divided in three horizontal areas:

  1. The Scale Area is the topmost area with a dark background. When the grid is enabled, the beats (1q, 2q, 3q, ...) are displayed in this area.
  2. The Curve Area is the second one an has a slightly lighter background. It takes almost 90% of the height and contains the envelope's curve.
  3. At the bottom there is again an area with a dark background which is called the Loop Handle Area.

Scale Area

When the grid is enabled, the beats (quarters) are displayed in the scale area. With the scale area the curve display can also be scrolled and zoomed:

Scrolling left-click + dragging
Zooming left-click + Alt + dragging

[Curve Display]

Curve Area

In the curve area the envelope curve can be defined by placing and dragging the curve handles. There are two types of handles which are depicted a square or a circle.

Square Mathematically spoken, at a square handle the envelope curve is unsteady, i.e. the curve before the point has no influence on the curve after the point and vice versa. This enables very sharp bends like percussive attacks and alike.
Circle At a circular handle the envelope curve is interpolated such that smooth sine-like curves can be achieved.

The following operations can be applied in the curve area between the first and the last handle of the envelope:

Create Handle left-click into empty space for square handle
left-click + Alt into empty space for circular handle
Delete Handle left-click + Ctrl into existing handle
Note, that the first and the last handle of an envelope cannot be deleted.
Switch Handle Type left-click + Alt into existing handle
Note, that the first and the last handle of an envelope are always of type square.
Drag Single Handle left-click into existing handle + dragging
Drag Complete Tail left-click + Shift into existing handle (NOT the last one) + dragging
Stretch Whole Curve left-click + Shift intfo the last handle + dragging

[Curve Display]

Loop Handle Area

At the lower end the loop markers have a triagular handle each. The loop start handle points to the left, whereas the loop end marker points to the right. The loop markers can be positioned by clicking into the handles and drag them. The loop start marker can be dragged between the beginning of the envelope curve and the loop end marker. The loop end marker can be dragged between the loop start marker and the ending of the envelope curve.

Three loop modes can be achieved by correctly positioning the loop markers:

Loop The loop start marker is positioned left of the loop end marker. In this case the envelope loops between to two marker positions as long as the keyboard is not released, i.e. as long as MIDI note off is not received. See ENV 2 .. 4 in the above image for an example.
Note, that unlike the LFOs this type of oscillation is voice specific.
Pause Loop start and loop end markers are dragged to the same position somewhere within the envelope curve. In this case, the envelope pauses at the position specified by the loop markers until the keyboard is released, i.e. MIDI note off is received. See ENV 1 in the above image for an example, which implements a classical ADSR (Attack, Decay, Sustain, Release) curve.
One-Shot If both loop markers are positioned at the end of the envelope there is no looping at all. See ENV 5 in the above image for an example.

[Curve Display]


  1. Sense
  2. Grid Mode
  3. Snap To Grid


Sense determines the influence of the key press (MIDI note on) velocity on the maximum output level of the envelope. A value of 0% means no influence and, hence, maximum output and a value of 100% means total impact of the keyboard velocity.


Grid Mode

The grid of the curve display always refers to the beats per minute, i.e. quarter notes. Grid Mode determines the scaling of the grid from "None" to a scale division of 8.


Snap To Grid

Snap To Grid enables some degree of "magnetism" of the grid in the curve display to the handles of the envelope curve and the loop delimiters. This facilitates the creation of envelopes which are perfectly synchronized to the beats.



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