Future Sound Systems ENV1 Cyclical Function Generator

Future Sound Systems are proud to release the Cyclical Function Generator ENV1 Eurorack module to the world; a fully-featured function generator for your eurorack system.

The CFG was designed preliminarily for Cric, yet stands as a fully-featured function generator for modular systems too. Each ENV1 module features two CFGs, with each featuring:

• an Attack and Decay stage
• different shape modes for the two stages (linear, exponential or logarithmic)
  
• modulation over each stage's time
• a Pulse output, switchable between an End of Decay pulse or a Comparator output which goes high when the CFG slope is above 50% of its total range
• three modes of operation - looping, attack/decay and attack/sustain/decay
• a Loop input, coupled with jumpers on the rear of the module to also force each CFG to trigger on an incoming pulse to this input

The CFG has been designed to cover a wide time range for both attack and decay stages, with their minimum times resulting in oscillations in the kHz range, up to their maximum times of several minutes per stage for a single cycle.

The Pulse source derived from each CFG can be switched between End of Decay (EoD) or Comp. In EoD mode, a brief trigger is sent as soon as the Decay stage has completed. This can be used to chain several CFGs together in a sequential fashion. Meanwhile, in Comp mode, a comparator sends a pulse which is high as long as the Slope is above the midpoint of its range, and low when it is beneath this midpoint. With Attack and Decay set to produce a perfectly triangular slope, a 50:50 square wave will be generated in Comp mode.

The CV Depth attenuverters follow the law that, for a positive voltage source at the corresponding destination, negative settings (anti-clockwise from 12 o’clock) reduce the stage times and positive settings (clockwise from 12 o’clock) extend the stage times. Without a jack present at the corresponding input, the CV Depth control becomes a fine tune for each stage, which is particularly useful if using the CFG as an audible oscillator.

As with many "West coast" inspired function generators, each CFG can cover a plethora of use cases:

• low-frequency oscillator
• envelope generator
• frequency sub-divider / sub-harmonic generator
• audio oscillator
• pulse-train generator
• gate/trigger delay and monostable