Generates a sequence of curves.

DHE Modules includes three Curve Sequencer modules:

• Curve Sequencer 4 (shown).
• Curve Sequencer 8.
• Curve Sequencer 16.

The three modules operate identically, except for the number of steps.

Note: The Curve Sequencer modules are deprecated. New patches should use Sequencizer instead. See How to Convert Curve Sequencer Presets to Sequencizer Presets.

See also:

• Factory Presets for descriptions of the presets included with the modules.
• Usage Notes for basic ideas about how to use these modules.
• Details for explanations of several non-intuitive aspects of these modules.
• J and S Curves

Controls

Each Curve Sequencer has controls for the overall sequence and controls for each step in the sequence.

Sequence Controls

• RUN: Determines whether the sequencer is running.

  If RUN falls while a sequence is in progress, the sequencer pauses the sequence. If RUN rises while a sequence is paused, the sequencer resumes the sequence.

• LOOP: If LOOP is on when a sequence ends, the sequencer immediately begins a new sequence.

  If LOOP is off when a sequence ends, the sequencer becomes idle.

• START and LENGTH select the steps of the sequence.

  Bracket-shaped markers next to the ACTIVITY lights indicate the currently selected steps.

• GATE: Controls when a sequence starts, and may influence when the sequence advances.

  If GATE rises while the sequencer is idle, the sequencer starts the sequence, activating the first selected, enabled step.

  See the ADVANCE step controls for details of how an individual step may react to GATE conditions.

• RESET: When RESET rises, the sequencer becomes idle, abandoning any paused or in-progress sequence.

  See details for explanations of several likely non-intuitive aspects of the RESET feature.

• IN: The input signal to the curve sequencer.

• OUT: The output signal from the curve sequencer.

Step Controls

• ACTIVITY lights indicate which step is active (if any), and how far the active step has progressed. When a step starts, its light is red. If the step is in a timed mode (CURVE, HOLD, INPUT, CHASE, or LEVEL), the light transitions from red to green over the step’s duration. Note that the light indicates progress, not voltage.

• MODE: Selects what kind of envelope stage this step generates:

  • CURVE mode generates a curve ending at the LEVEL voltage. The SHAPE, CURVE, and DURATION controls govern the shape and duration of the curve.

  • HOLD mode holds the OUT port at its current voltage for the duration selected by the DURATION controls.

  • SUSTAIN mode sustains the OUT port at its current voltage until the GATE condition selected by the ADVANCE stepper occurs.

  • INPUT mode sends the IN signal to the OUT port for the duration selected by the DURATION controls.

  • CHASE mode generates a curve that progressively approaches the IN voltage. The SHAPE, CURVE, and DURATION controls govern the shape and duration of the approach.

  • LEVEL mode sends the LEVEL voltage to the OUT port.

• ADVANCE: Selects the condition that triggers the sequencer to advance from this step to the next.

  • TIME: The sequencer advances to the next step when this step completes its full duration. The state of the GATE is ignored.

    Selecting this option for a step in SUSTAIN mode disables the step.

  • RISE: If the GATE rises while this step is active, the sequencer advances to the next step.

  • FALL: If the GATE falls while this step is active, the sequencer advances to the next step.

  • EDGE: If the GATE rises or falls while this step is active, the sequencer advances to the next step.

  • HIGH: If the GATE is high while this step is active, the sequencer advances to the next step.

  • LOW: If the GATE is low while this step is active, the sequencer advances to the next step.

• LEVEL: The voltage at which the curve ends. The range of each LEVEL knob is set by the common LEVEL RANGE switch (to the right of the LEVEL knobs).

• SHAPE: Selects the shape of the curve.

• CURVE: The curvature of the curve.

• DURATION: The duration of the CURVE or HOLD. The range of each DURATION knob is set by the common DURATION RANGE switch (to the right of the DURATION knobs).

• ENABLED: Determines whether the sequencer can enter this step. When ENABLED is off, the sequencer bypasses this step when advancing.

Factory Presets

The Curve Sequencer 4 module includes these factory presets:

• AD: Generates an Attack Decay envelope.
• ADHR: Generates an Attack Decay Hold Release envelope.
• ADSR: Generates an Attack Decay Sustain Release envelope.
• AHR: Generates an Attack Hold Release envelope.
• ASR: Generates an Attack Sustain Release envelope.
• Batman: Calls for help.

Usage Notes

To create a traditional sequencer step. Select LEVEL mode and set the step to ADVANCE on RISE. Then set the duration longer than the clock cycle. Note that using the other ADVANCE options give you a great deal of flexibility compared to a traditional sequencer.

INPUT mode essentially bypasses the sequencer for the duration of the step.

CHASE mode generates a curve that chases a moving target: The voltage at the IN port.

To restart a sequence. To interrupt a sequence and start a new sequence, send a rising edge to both RESET and GATE. The rising RESET resets the sequencer to idle. The rising GATE immediately starts the next sequence.

To start a sequence at a specified voltage.

• Feed the IN port a signal with the desired voltage.
• Send a rising edge to both RESET and GATE. The rising RESET copies the IN voltage to the OUT port. The rising GATE immediately starts a new sequence starting from the OUT port voltage.

To skip a series of steps. Set a series of adjacent steps to advance on the same GATE value

either HIGH or LOW. If the selected value appears at the GATE while any of those steps is active, the sequencer immediately completes the active step and all of the successive steps with the same ADVANCE condition, and executes the next available step that has a different ADVANCE condition.

For example, to generate an ADSR envelope that jumps to the Release step when the GATE goes low, set the ADVANCE condition of the Attack, Decay, and Sustain steps to LOW.

To track the IN voltage. If RESET is high while the sequencer is idle, the sequencer copies the IN voltage to the OUT port. So if you want control the sequencer externally to “track” the IN signal:

• Send a rising signal to RESET. The sequencer interrupts any sequence in progress and becomes idle.
• Hold RESET high. As long as RESET is high and the sequencer is idle, the sequencer copies IN to OUT.
• Prevent GATE from rising. If GATE rises while the sequencer is idle, the sequencer starts a sequence and stops tracking IN (unless the first selected step is in INPUT mode).
• To stop tracking, set RESET low or send a rising signal to GATE.

Pausing and resuming a sequence. Turning RUN off while a sequence is in progress pauses the sequence. When RUN turns on, the sequence resumes from the point where it was paused.

Details

Several aspects of the Curve Sequencer modules, though purposefully designed, may be unexpected:

• ADVANCE options and timed modes. If the active step is in one of the timed modes (CURVE, HOLD, INPUT, CHASE, or LEVEL), the sequencer advances to the next step as soon as either or both of these things occurs:

  • The active step completes its duration.
  • The GATE satisfies the ADVANCE condition.

  If the active step completes its duration, the sequencer advances to the next step regardless of whether the GATE satisfies the ADVANCE condition.

  If the GATE satisfies the ADVANCE condition, the sequencer advances to the next step regardless of whether the active step regardless of whether the active step has completed its duration.

• The starting voltage of each mode. A step in CURVE, HOLD, SUSTAIN, or CHASE mode starts at the current OUT port voltage.

  A step in INPUT mode starts at the the voltage at the IN port. and tracks the IN signal for the duration.

  A step in LEVEL mode starts at the voltage specified by the LEVEL controls and tracks the value of those controls for the duration.

• Once started, a step always completes. Once a step starts, it always proceeds as if enabled, even if ENABLED is turned off while the step is in progress.

• RESET and RUN. A rising RESET resets the sequencer to idle even while RUN is off. If RUN is on, a rising RESET abandons any sequence in progress. If RUN is off, a rising RESET abandons any paused sequence.

• RESET, idle mode, and the IN port. While the sequencer is idle and RESET is high, the sequencer copies the IN port voltage to the OUT port.