rossum-electro/control-forge

Control Forge

Rossum Electro-Music

Programmable Universal CV Generator with 8-segment function generator, 67 transition shapes, conditional jumps, AutoChain, preset sequencer, and two programmable triggers — inspired by the E-mu Morpheus Function Generators.985

Capabilities 4

Envelope Generatorenvelope-generator
Programs ADSR-style and complex multi-stage envelopes using conditional jumps and Gate Fall Jump; each stage can have multiple segments with distinct shapes.985
Function Generatorfunction-generator
8-segment programmable function generator with variable time, level, and 67 transition shapes per segment; supports one-shot and cyclical operation.985
LFOlfo
Creates cyclical LFO-style patterns via Free Run or Always-at-End jumps back to Segment 1; can be retriggered and time-scaled in real time.985
Sequencersequencer
Uses DC Delay shapes and AbsQ Level Mode to create traditional step sequences of up to 8 steps per preset; extended via Preset Sequencer or preset chaining for sequences of hundreds of steps.985

Jacks 12 (8 in / 4 out)

NameSignalVoltageDescription
Inputs (8)
CV 1cv-5V to 5VCV input used for conditional jump testing, CV passthrough to output during selected segments, and data loading via utility functions.985
CV 2cv-5V to 5VCV input used for conditional jump testing and CV passthrough to output during selected segments.985
Gate/TriggateAccepts triggers and gates; controls contour start, reset, and conditional jumps based on Preset Globals settings.985
LogicgateDigital logic input used for conditional jump tests; rising/falling edges or high/low states can be tested per-segment.985
Preset Sequencer DECtrigger985
Preset Sequencer INCtrigger985
Preset Sequencer RESETtrigger985
Time Scale CVcv-5V to 5VModulates the time values of all segments; a 1V change scales the rate by a factor of 2, multiplied by the encoder time scale value.985
Outputs (4)
+ Outputcv-5V to 5VMain CV contour output; outputs the programmed voltage contour, accurate to 1mV or better over the full range.985
- (Inverted) Outputcv-5V to 5VInverted CV contour output; the polarity-inverted version of the + Output, accurate to 2mV or better.985
Trigger 1trigger≤10VProgrammable trigger/gate output that fires based on user-assigned conditions; width is selectable from fast pulse to percentage of segment length.985
Trigger 2trigger≤10VSecond programmable trigger/gate output; also used as a data transmission line when sending presets to a Satellite or another Control Forge.985

Parameters 15

NameTypeRangeBehavior
Assign TriggersbuttonPrograms the firing conditions for Trigger 1 and Trigger 2 outputs; conditions include gate/logic events, segment begin/end events, and jump events; width is also configurable.985
Conditional Valuebutton-5V – 5VSets the voltage threshold used when the Jump Mode tests a CV input or knob; ignored when Jump Mode does not involve a CV comparison.985
CV 3 (Time Knob)knobThe Time knob doubles as CV 3 in Play Mode, allowing manual real-time setting of a CV value for conditional jump tests and CV passthrough segments.985
CV 4 (Level Knob)knobThe Level knob doubles as CV 4 in Play Mode, allowing manual real-time setting of a CV value for conditional jump tests and CV passthrough segments.985
Data/Time Scale Encoderknob0.031 – 32In Program Mode, sets parameter values. In Play Mode, controls time scale in approximately logarithmic steps; its value is multiplied by the Time Scale CV to give the final time scale.985
Jump ModebuttonSelects the condition under which the segment will jump to the Jump Target; options include Never, Always at End, on Gate Rise/Fall, wait modes, Logic conditions, and CV threshold comparisons.985
Jump TargetbuttonSelects the destination when a conditional jump fires; can target a segment (1-8), a stop state, preset sequencer commands (Dec/Inc/Reset), or a specific saved preset.985
LevelknobSets the target voltage level the segment will reach at its end; affected by Level Mode (Absolute, AbsQ, Relative, RelQ). Clamped to ±5V in Relative modes.985
Mode/QuantizebuttonCycles through four Level Modes: Absolute, Absolute Quantized (1/12V steps), Relative, and Relative Quantized. An LED indicates whether Absolute or Relative is active.985
Randomnessbutton0V – 5VSets the symmetrical range in volts within which the segment's Target Level will be randomly varied; distribution can be Linear or Gaussian. Interacts with Level Mode.985
Reset Levelmenu_setting-5V – 5VSets the initial voltage level at the start of a contour when Start Level is set to Reset.985
Reset Random Levelmenu_setting0V – 5V985
Scale All Timesmenu_setting0.031 – 32Destructively rescales all segment time values by a multiplier, preserving relative rhythmic relationships. The initial value is the most recently captured encoder Time Scale.985
Timeknob0.0001s – 9999sSets the duration of the currently selected segment; can be fine-tuned with the encoder after initial knob adjustment.985
Transition ShapebuttonSelects one of 67 transition shapes for the segment's trajectory between start and target level; includes linear, exponential, circular, chaos, random, zig-zag, DC, and CV passthrough shapes.985

Firmware history 1 version

VersionReleasedNotes
v1.01c2017-06-08Added OLED brightness control and screensaver. Added Tempo Mode for specifying segment lengths in musical note values (BPM). Fixed display flicker. Fixed Preset Globals field selection skipping disabled Reset Level when Start Level is Current. Fixed faulty preset 457. Added template preset 320.985

References 2

  1. [985]
    Rossum Control Forge Manualmanual
    verified 2026-05-26
  2. [986]
    Rossum Control Forge product pageproduct_page
    verified 2026-05-26