Func - Function Generator

Type: Module

Category: Envelope generators

Updated: Apr 11, 2021

Manufacturer: Collider Modular

Contact Manufacturer

Documentation & Help

$10.00 $18.00

On Sale


Func: The multi tool function generator 🛠️

  • 2 channels (x, y)
  • 4 function modes (attack/decay, attack/release, looping/LFO, and gated loop)
  • Variable function shape
  • End of decay trigger
  • Independent clock syncable duration per channel
  • Independent clock division and multiplication per channel
  • Blendable output ("OR") with additional mangling on tap
  • Integrated stereo VCA
  • 4 blinking LEDs to impress your non-modular friends

Func can be used as a...

  • Envelope generator
  • Clock synced LFO
  • Stereo VCA
  • Burst generator
  • Clock source
  • Clock divider/multiplier
  • Source of wild control voltage

Video Manual:


Attack Decay (AD)

In AD mode, when a rising edge (trigger, gate) is received at "Gate In", the control voltage rises from 0.0 to 5.0 following the chosen shape. As soon as the attack phase is complete, the decay phase begins.

AD mode outputs a unipolar signal.

Attack Release (AR)

In AR, sometimes called AHR (attack hold release), mode, when a rising edge (gate) is received at "Gate In", the control voltage rises from 0.0 to 5.0. It remains high while the input at "Gate In" remains high. Once the input drops low, the decay phase drops from 5.0 to 0.0.

Note that in AR mode, the Time + Skew setting affect the total time in a slightly different way. While in AD mode, Time sets the total time, in AR mode on the attack phase is counted towards the function's time. The decay (release) time is in addition to that.

AR mode outputs a unipolar signal.

Looping (LFO)

In Looping mode, Func behaves the same as in AD mode, except that as soon as the decay phase is finished, a new attack phase is triggered.

Looping mode outputs a bipolar signal.

Gated Loop

Gated Loop mode is like AR and looping mode combined. It outputs a bipolar looping function as long as the input gate remains high.

Gated loop mode outputs a bipolar signal.


Func supports synchronization with an external clock.

  • When no clock signal is patched, the Time knob sets the function duration in milliseconds.
  • When a clock signal is patched, the Time knob is instead synchronized with the external clock signal. With the Time knob straight up ("noon" position), the duration of the function will be identical to the source clock. When the Time knob is turned to the left, the clock signal will be divided, from 1.5 times slower to 16 times slower. When the Time knob is turned to the right, the clock signal will be multiplied, from 1.5 times faster to 16 times faster.

Special note about digital clock signals: Func works like most digital modules in that it takes 2 cycles, at a minimum, to detect the clock duration. To minimize the effects of digital sampling, the duration of clock pulses are averaged together. This means that the clock input works best with a stable signal. When fed a highly variable clock source, a slewing of time will occur, with the module taking a few milliseconds to stabilize to the new time. This can be intentionally misused for creative effect if so desired.

Global Features


Blend combines the X and Y channels of Func into a single output. The knob shifts the bias, giving more or less of a given channel. The blended signal can be distorted or inverted with the Mutate knob.


Signals patched to input jacks labeled "VCA IN" will be attenuated by the X or Y channel respecitvely on the corresponding "VCA OUT" outputs. Input value patched to X is automatically normaled to Y's input when no cable for Y is present.


Func contains two channels. Both are identical and independent, but can be cross-patched for interesting results.


  • Shape - Adjust the attack slope and decay slope of the function; Continuously variable; Can be modulated with the "Shape" input jack.
  • Skew - Sets the percentage of time the attack versus decay phase tacks. Pointing straight up ("noon" position) the duration is split 50/50 between attack and decay. As the knob is turned to the left, more time is given to decay. As it is turned to the right, more time is given to attack.
  • Time - When no clock is connected, Time sets the total time for attack and decay to complete. When a clock signal is connected, this knob instead seats the clock divisor or multiplier.
  • Mode - Changes the channel mode.
  • Gate Button - Triggers the function. When in AR and gated loop mode, the button can be held down to keep the gate signal high.
  • Blend - Controls the balance of combining the values of the X and Y channels together. To the left adds more X channel signal. To the right adds more Y channel signal.
  • Mutate - Modifies the blended signal. Turning to the left causes the signal to become stepped. Turning to the right blends between combinations of rectification and inversion.


  • Gate In - Triggers the function when > 4v is detected
  • Shape - Modulates the shape position. This value is added to the position of the shape knob. The attenuator can be used to attenuate or invert the incoming control voltage.
  • Time - Modules the time position. Without a clock connected, it modulates the real duration. With a clock connected, it modulates the division or multiplication of the clock.
  • Clock - See "Clock" above.


  • OUT - The control voltage output of the function (ie. envelope or LFO CV). Range is 0.0 to 5.0v
  • END - A 5ms trigger that happens as soon as the decay or release phase of the function completes. In LFO mode this behaves like a clock signal, and can be used to self-trigger or trigger another channel.

Tips & Ideas

Burst Generator

Set the X channel to a triangular shape, and looping mode. Next, patch the "OUT" jack to the "Time" jack of the Y channel. Set the time attenuator at max value (towards the "+"). Whenever the Y channel receives a gate input, a stutter of triggers will appear on the Y channel "END" jack.

Cross Patched LFO for Complex Shapes

The output of the Y channel can modulate the "Shape" or "Warp" parameters of the X channel. Normally this would produce unpredictable results. However, by patching the "END" output of the X channel to the "Clock" input of the Y channel, it synchronizes the two function so that modulation occurs at the same rate on both channels.

Furthermore, if both channels are running in LFO mode, the Y channel can be divided or multiplied to make shape modulation that takes several cycles to change the X channel shape, but remains synchronized and predictable.

Stereo VCA

The input of the X channel VCA IN is normaled to the Y channel input. Patching a single input the X VCA IN, then synchronizing the two channels to the same clock duration, allows the warp or shape to be subtly changed for the Left and Right channel, creating a kind of stereo widening.

Func as a Clock Source

Setting the channel mode to looping, the "END" output then becomes a clock signal. The Time knob can be used to set a specific BPM. The math is 60,000 / BPM = duration. Thus, to have a clock signal at 120 BPM, set the Time knob to 500 (60,000 / 120 = 500). Right-click the Time knob and chose "Edit value". This allows a precise value to be entered.

Clock Divider or Multiplier

With an external clock signal patched to the "Clock" input, the Time knob now becomes a clock divider or multiplier, with the divided or multiplied clock signal appearing on "END".

Change Log

April 11, 2021

  • Improvement: Re-wrote internal clock with improved precision and better response to changing BPM
  • Improvement: Module will now emit a single trigger when changing mode or reloading from a saved state, if Gate In jack is connected
  • Bug: Fixed a bug where triggering looping mode with Gate In would cause the polarity to get 'stuck'

March 9, 2021

  • Initial release