Control Forge

Programmable Universal CV Generator

Control Forge Firmware v1.01c 170608 has been released. Check the Downloads tab for details.

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.
  • A new “Tempo Mode” lets you specify each segment’s length in musical note values relative to a tempo set in BPM.
  • 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.

BPM Mode Demo

A video introduction to the BPM Mode introduced in firmware version 1.01c. Another great video 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)

What’s New in Firmware Version v1.01c 170608 (PDF)

Download the latest Control Forge firmware and Factory Presets.

There is an updated version of Control Forge firmware!

There is a (slightly) updated version of Control Forge factory presets.

The latest version of Control Forge firmware is v1.01c 170608.

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.

What’s New in Version 1.01c 170608

OLED Brightness and Screensaver

OLED displays have long lifetimes under normal use, but if you leave your system on 24/7 (or just want to ensure the longest possible life for your display), you can adjust the brightness of the display (which is also useful for optimizing it for the ambient lighting level of your work environment) and, optionally, you can set a time after which the display enters a screensaver mode. Both of these can help extend the life of your display.

NOTE: Once the screen saver has appeared, any button press or a turn of the encoder will dismiss it and return to the regular display. Such encoder turns or button presses are not registered as control inputs.

ANOTHER NOTE: The screen saver will not appear when you are executing a Utilities Menu function. However, it will appear if the Utilities Menu is displayed (but no function selected).

Here’s how it works:

– Select Utilities > OLED Control on your Control Forge.

– Turn the encoder to select a brightness level of 1-11. You’ll see the display change in brightness as you scroll through the values. The value number also changes color to indicate their effect on OLED life (Green=great, Yellow=okay, Red=beware if you leave your system on 24/7)

– Click the encoder to move to the ScreenSaver setting.

–  Turn the encoder to select the time after which the screen saver will appear. Choices range from 2 minutes to 60 minutes and “Never.” If you consistently leave your system on long periods of time, “Never” is probably not a good choice.

NOTE: The screen saver is a small version of Control Forge’s Segment Shape plot that moves randomly around the display. Note that this plot is actually functional, responding in real time to segment changes.

Tempo Mode

Tempo Mode gives you the option of specifying Segment Length in musical note values relative to a tempo (in BPM) specified in the Preset Globals Menu.

Here are the details:

–  There’s a new item in Preset Globals: Tempo Mode. When it’s “Off,” everything works like it always has. When it’s at any other setting (i.e., a tempo in BPM):

– The Play Mode screen displays “Tempo” instead of “Time Scale

– In Program Mode, the Time parameter for each Segment is displayed in note values (e.g., 1/8, 1/2t, 1/4d – t=triplet, d=dotted, ( 1 )=whole note, ( 2 )= 2x whole note, etc.). The range is from 1/128th note to 32 whole notes.

– Double-clicking the encoder toggles between tempo/note display and the equivalent time display.

NOTE: Setting the Mode in the Preset Globals menu and saving the preset saves that setting. The double-click action is temporary and its state is not saved. If you load another preset, its Tempo Mode setting overrides the double-click state.

IMPORTANT: The above note also means that if Tempo Mode is not set in the Preset Globals Menu and you use the double-click to temporarily switch to Tempo Mode and then save the preset, the preset is NOT saved in Tempo Mode. The only way to save a preset in Tempo Mode is to set it in Preset Globals and then save the preset.

ANOTHER NOTE: If Tempo Mode is turned off in the Globals menu, using the double-click to temporarily turn it on assumes a default tempo of 120BPM, which can then be changed by the encoder or Time Scale CV in Play Mode.

Other Stuff

– Fixed: A problem that sometimes caused the top few lines of the display to flicker or pulse.

– Fixed: In Preset Globals, field selection now skips over the disabled Reset Level when Start Level is set to Current

– A few other internal bits no one but us noticed.

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_v1.01_170608.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_v1.01c2_170621.wav as a zip archive.

Factory Presets

If, for any reason, you need to reload Control Forge’s factory presets, download the file below and use the Load User Data function to load it into your Control Forge. Alternatively, you can use Merge User Data to load it and leave any other presets you might have created intact.

This updated version of presets contains the following changes from the originally shipping version:

– Fixed faulty preset 457
– Added template preset 320 (External clock sync via WaitForLogicRise)

Click here to download