This manual covers Ohmicide firmware v1.0
Ohmicide is a stereo distortion Eurorack module, inspired by its eponymous software plug-in.
Automate for live conditions with small rack space. Rythmic distortions
Follow the instructions below carefully to avoid any damages.
The USB port is only used to update the module firmware.
The signal is first splitted into 2 bands using the XOVER parameter. The lower band is not processed, allowing to preserve the bass content for more control.
The higher band then goes into a Low-pass filter which frequency is controlled with LPF IN. This allows to remove smoothly some harmonic content before new one is added in the distortion stage.
The distortion is selected using the TYPE parameter. 37 different distortions are available, ranging from wave shapers, wave folding, saturation, overdrive, fuzz, bit crushing and completely novel distortions including a fractal chaotic feedback equation, cyclic distortions, slew rate limiters, sample & hold analog emulation, noise based distortions, a ball bouncing on walls which velocity is controlled by the input signal, a fridge emulation or one based on Lorenz strange attractors.
Each distortion then has 3 variants using the FAM switch:
The distortion can be further controlled using the BIAS and MOD parameters:
For FAM Standard and Xxx, the BIAS parameter emulates malfunctioning hardware circuirty and adds a DC offset before the distortion is applied. But don't worry, this DC offset is removed later in the signal path. For FAM Odd, the BIAS parameter controls the distance between harmonics: normally a distortion harmonics are all multiplicative of the fundamental. FAM Odd allows to expand or shrink the relation between those harmonics, making it inharmonic.
The MOD parameter is then specific for each distortion. For example it brings even harmonics for wave shapers, or change the base parameters of the algorithm itself.
Each distortion has of course a GAIN parameter from very low to extreme gain settings, with very low noise at extreme gain settings thanks to its clean audio analog circuitry.
Finally the distorted signal reaches another Low-pass filter which frequency is controlled with LPF OUT. This allows to "tame" the distortion by removing progressively the harmonics generated in the distortion stage.
In total, Ohmicide has 111 distinct sound possibilities, with BIAS and MOD for infinite number of variations.
The Ohmicide has an automatic gain staging which preserves on output the power of the input signal. This allows to play with the module without fearing the module would suddenly be extremely loud.
Every parameter can be CV controlled, and on top of that, GAIN, MOD, BIAS and XOVER also have attenuverters.
The PRODUCER mode, the default when the module is switched on, is typically used at home or in the studio. No menu diving, and every change of parameter is instant. This allows for example to cycle through the entire list of distortions TYPE by just turning the encoder, letting one to "dial-in" the perfect distortion for the input sound quickly.
The more advanced Performer modes are typically used when preparing for live conditions with limited rack space. The Ohmicide software plug-in originally introduced the "Melohman" feature which allowed to "play" the plug-in using a MIDI keyboard, and this feature was adapted to Eurorack and its CV/Gate-centric workflow.
The SIMPLE Performer mode is exactly like Producer mode, except a click on the encoder is needed to activate the selected distortion. Compared to the Producer mode, this allows to "jump" to a specific distortion without hearing all the distortions in between.
To access Simple mode, press TYPE for 2 seconds, a menu will appear. By rotating TYPE, navigate to PERFORMER and click TYPE. SIMPLE is already selected, press TYPE. The module will go back to its initial screen, except the frame around the current distortion is dashed.
Rotate TYPE to select the distortion. The screen will blink and show the current active distortion, and the latent one. The latent one will become the current active distortion when TYPE is pressed again.
Note: The distortion becomes active exactly when the TYPE button is released. This allows to be more precise in Live conditions, and is a common feature found on DJ consoles.
To go back to PRODUCER mode, press TYPE for 2 seconds. PRODUCER is already selected, press TYPE. You are back in the default mode.
The CV MODE and TRIGGER MODE Performer modes work as a mini-sequencer inside Ohmicide, with as much as 16 individual sequences. In PRODUCER mode, you can double click on TYPE and save the current Ohmicide knobs and distos configuration in a step of the current selected sequence, for a maximum of 8 steps. In those two modes, the TYPE knob and associated CV refers to a step in the sequence.
This sequence can be then played back either as a classical step sequencer using TRIGGER MODE where the TYPE jack input acts as a trigger input, or using it as a CV to address steps in any order using CV MODE.
The sequence length can be tuned from 1 to 8 steps, and the TYPE CV input in CV MODE can be configured to handle either ±5V or 0..5V depending on the capabilities of the module controlling it.
For even more playability, each knob of a song can be configured further:
To select the current sequence, press the TYPE encoder for 2 seconds, navigate to PERFORMER, then CUR SEQ. Press the encoder. By rotating the TYPE encoder choose the current sequence from 1 to 16. Once selected, navigate to BACK, press the encoder, and repeat this to go back to the initial screen.
To save the current configuration of the knobs and switches, first make sure you are in PRODUCER mode. Then press the TYPE encoder two times quickly, and the "save step" menu will appear. The first line shows the current selected sequence and allows to exit without saving the step. To save a step into the sequence, rotate the encoder to the desired step and press the encoder. The step is then saved and the module will go back to the initial screen.
To activate CV MODE or TRIGGER MODE, press the TYPE encoder for 2 seconds, navigate to PERFORMER and then choose one of those two modes and press the encoder. The module will go back to the initial screen and will show a mini representation of the sequence:
Show sequence.
To change the length of the sequence, press the TYPE encoder for 2 seconds, navigate to PERFORMER and then SEQ LEN. Press the encoder, and rotate it to choose the desired length from 1 to 8. Once selected, navigate to BACK, press the encoder, and repeat this to go back to the initial screen. The screen will now show the new sequence length.
To change the start of the sequence, rotate the TYPE encoder. The screen will blink and show the current active start, and the latent one. The latent one will become the current active start when the encoder is pressed again. In TRIGGER MODE this will also reset the current step.
Simply pressing the encoder while in TRIGGER MODE will reset the current step.
There are 2 ways to reset a step:
To change the step reset mode, press the TYPE encoder for 2 seconds, navigate to PERFORMER and then STP RST. Press the encoder, and rotate it to choose the desired mode, either IMDT (ie. immediate), or NEXT.
Finally to change the knobs option, press the TYPE encoder for 2 seconds, navigate to PERFORMER, then POTS OPTION. Navigate to the knob you desired to change, press the encoder and rotate it to choose either LAT (Latch), REL (Relative) or OVR (Override).
By default, All CVs are ±5V, but this is not always a good option, in particular for TYPE which controls also the step in a sequence, or FAM.
Depending on your module controlling CV, some might not be able to generate negative voltages. In this case you can use the 0..5V instead.
To change the CV range of TYPE and FAM, press the TYPE encoder for 2 seconds, navigate to SETTINGS, and then to either TYPE CV of FAM CV. Click the encoder and change the value to the desired range.
Typically for shooting a video in a controlled light environment, the screen contrast might be too high, and you might not want the screen saver to trigger.
To change the contrast of the screen, navigate to SETTINGS, then SCREEN and finally CONTRAST. Click the encoder and change to value to the desired contrast, from 0 to 15.
To change the screen saver option, navigate to SETTINGS, then SCREEN and finally SAVER. Click the encoder and change to value to the desired value, either ON or OFF.
Thanks to the Daisy platform, upgrading the firmware of your module only requires a USB micro cable and a computer with the Google Chrome web browser installed.
Upgrading the firmware brings new features and bug corrections. You don't need to update the firmware if the firmware version already matches the one installed in your module.
To check your firmware version, press the TYPE encoder for 2 seconds and look at the version displayed at the bottom of the screen.
For complete up-to-date instructions, please refer to the firmware update page that can be found on the Ohmicide product page.
But in general:
Depending on electrical conditions or ambiant temperature, your module CV and knobs might be slightly off and might require recalibration.
Also, should you have a problem with the module, our support team will ask you to run "test mode" to have a rough idea of what the problem is.
This operation requires a bit of care because the module will need to be powered by your Eurorack case in order to complete successfully. You will also need a simple LFO and VCO.
To enter test mode and calibration: