Control Forge

Programmable Universal CV Generator

CONTROL FORGE’s core functionality is drawn from the E-mu Morpheus’s insanely powerful (but hard to program on a two-line display) Function Generators. But now expanded into a supremely flexible modulation source encompassing elaborate one-shot contours, evolving cyclical patterns and sequences of arbitrary length and complexity.

  • At its most basic, it’s an 8-segment function generator with variable time and target voltage level for each segment.
  • Each segment’s level can be defined either absolutely or relative to the ending level of the previous stage and can optionally be quantized to the nearest 1/12 volt.
  • Each segment’s level may have a user defined range of randomness of either linear or gaussian distribution.
  • The time scale may be modulated under CV control or manually via the encoder during runtime.
  • There are 67 different transition shapes between segments (indicated graphically on the display during selection), from linear and exponential shapes to various flavors of random, chaotic, and many more that don’t lend themselves to one-word descriptions, including the ability to pass CVs directly through to the output for individual segments.
  • Also included are “DC” shapes that allow the module to be used as a sequencer with all of the module’s available programmability. When combined with the Preset Sequencer described below, sequences can be hundreds of steps long and modified in real time manually or by CVs.
  • Each segment may optionally have a conditional jump mode that results in a jump to another selected stage if a particular condition is met. E.g., a CV being above or below the selected conditional value, the presence or lack of a gate or logic high at their respective inputs, rising or falling edges at the inputs, etc. So, in addition to one-shot shapes, extremely elaborate cyclical patterns can be programmed that evolve based on the various conditional inputs.
  • Control Forge’s AutoChain functionality allows the creation of two very specific kinds of multi-preset patterns: A multi-preset retriggerable pattern (like a long syncable LFO), and a multi-preset “envelope-like” pattern with retriggerablity, an optional sustain section, and a “release” section that’s jumped to on gate fall.
  • Two independent triggers can be programmed to fire in response to a variety of events and can be used to affect either CONTROL FORGE itself or external modules.
  • 500 presets can be saved and recalled
  • A preset sequencer allows stepping through up to 200 user-defined series of presets under trigger, clock or manual control. This allows contours and sequences of almost unlimited length and complexity.
  • All presets and sequences can be transferred to any number of Satellite modules, which can then operate as stand-alone modulation sources, completely independent of the Control Forge.

Like all Rossum Electro-Music digital modules, all parameters are available for adjustment with a single button press. No menu diving.

CONTROL FORGE is available from Rossum Electro-Music Dealers worldwide.


Control Forge Specifications






20,000 Dynamically Allocated



1x 3.5mm mono socket 100kΩ Input Impedance 1.6V threshold


1x 3.5mm mono socket 100kΩ Input Impedance 1.6V threshold

CV 1

1x 3.5mm mono socket 100kΩ Input Impedance -5V to +5V

CV 2

1x 3.5mm mono socket 100kΩ Input Impedance -5V to +5V

Time Scale CV

1x 3.5mm mono socket 100kΩ Input Impedance -5V to +5V

Preset Sequencer DEC

1x 3.5mm mono socket 100kΩ Input Impedance 1.6V threshold

Preset Sequencer INC

1x 3.5mm mono socket 100kΩ Input Impedance 1.6V threshold

Preset Sequencer RESET

1x 3.5mm mono socket 100kΩ Input Impedance 1.6V threshold


+ Output

1x 3.5mm mono socket <1Ω Output Impedance

-5V to +5V

Accurate to 1mV or better over the entire range

– (Inverted) Output

1x 3.5mm mono socket <1Ω Output Impedance

-5V to +5V

Accurate to 2mV or better over the entire range

Trigger 1

1x 3.5mm mono socket 1kΩ Output Impedance 10V
Selectable Width

Trigger 2

1x 3.5mm mono socket 1kΩ Output Impedance 10V
Selectable Width


+/-12V via 16-pin, Doepfer-style connector


125mA +12V, 25mA -12V (maximum)


22HP (W); Panel to power connector (with connector plugged in) 25mm (D)


1x 16-pin, Doepfer-style cable
4x M3 screws
4x M2.5 screws
4x Nylon washers

1x Quickstart Guide

Control Forge Introduction Video


Control Forge Tutorial/Demo

A great introductory Control Forge tutorial/demo from Martin Doudoroff.


Real-Time CV Modulation

From composer, sound designer, and beta tester extraordinaire, Kurt Kurasaki, a demonstration of using the Relative Quantized CV mode to generate 1v/oct patterns and then, using another CV source as the input, quantizing the input and then generating patterns based on the incoming voltage.

The Preset Sequencer

Another demo by Kurt, this time a Control Forge Preset Sequence driving a handful of modules with the CV out, inverted CV out, and the two trigger outputs. The Control Forge knobs have been programmed to act in a variety of functions as the sequencer steps through different presets.

Visual Control Voltages

Synthesist Worwell has created a fascinating video featuring a real-time scope display of his Control Forge’s CV contours along with the resulting audio.

View or download Control Forge documentation.

Control Forge QuickStart Guide (PDF)

Control Forge Owners Manual (PDF)

Download the latest Control Forge firmware.

The latest version of Control Forge firmware is v1.00c 161016.

To check the version that’s in your Control Forge, ensure that your Control Forge is in Play Mode and press and hold the Global button until the Utilities screen appears. Scroll to the bottom of the menu to see the current installed firmware version.

To update your firmware, you will need to play the .wav file linked below into the CV 1 Input of your Control Forge.

We’ve had good luck playing the file directly from a computer (but see the warnings below) and from mobile devices. In theory, any device that will play a .wav file without distorting the data should work. However, here are some caveats:

  • If you are steaming the file directly from the web, be sure that your data rate is sufficient to keep up. If necessary, wait until the file has been completely buffered before starting playback.
  • If you are playing through an audio interface, it should output line level.
  • If you are playing the file from a computer or phone, quit Facebook, your email client, and any other software that produces audio. Any other audio injected into the stream will cause the update to fail. If you’re using a smartphone, temporarily placing it in Airplane Mode will prevent any incoming call or message notifications from interfering with playback.
  • We have found that Safari on the Mac plays the file in a way that sometimes keeps it from being successfully recognized and decoded. If you are using Safari, we recommend downloading the zip archive below and playing the file from the local copy using Quicktime Player.
  • In fact, if you are having any problem streaming the file, downloading the zip archive is a good alternative.

To update the firmware in your Control Forge:

  • Connect a patch cable from the output of whatever you are using to play the .wav file to the CV 1 Input on your Control Forge (we’ve found that a regular Eurorack patch cord works fine)
  • Go to the Utilities Menu by long-pressing the Global Button while in Play Mode.
  • Select Load Software from the menu.
  • Press the Encoder switch twice as instructed.
  • Start playback of the .wav file. You should see a green progress message in the display:


  • When the file transfer is complete, press the Encoder again to reboot into your new firmware.



Click here to download ceres_v1.00c_161016.wav as a zip archive.

This is the latest Boot Software, should you ever need to reload it (unlikely). If you haven’t been instructed to come here as the result of a customer support issue, it’d be best to just ignore it.



Click here to download boot2_ceres_160813.wav as a zip archive.