EVENT DIY Kit- Eurorack Module by Rat King Modular

This is the DIY Kit of the EVENT Module from Rat King Modular.

VCO, envelope, slew limiter (portamento), waveshaper, LFO, envelope follower…
The EVENT does it all, making it one of the most versatile analog modules
available.

Controls:
- ONSET: Controls the positive rate (time) of change in voltage. It has a
bipolar CV input jack.
- DURATION: Controls the negative rate (time) of change in voltage. It has a
bipolar CV input jack.
- HEIGHT: Controls the held voltage level when a continuous gate is applied.
- TRACK: 1v/oct input. It is particularly useful when patching the EVENT as a
VCO.
- START: A simple gate/trigger/pulse input that initiates a cycle when the
EVENT is patched as a voltage controlled envelope.
- SIGNAL input: Can be a constant or fluctuating voltage. This input is
particularly useful for mangling CVs.
- SIG OUT: The main output, the result of the gate/trigger/pulse input or
SIGNAL input.
- PLS DLY: A short pulse used for triggering other events as pulse delay (or
as self trigger when patching the - EVENT back into itself).

Specifications:
- Module width: 8HP
- Module depth: 22mm
- Current draw:
+12V: 50mA
-12V: 43mA

View the assembly instructions here:
http://ratkingmodular.com/event-module-2/event-module-assembly-instructions/

View the bill of materials here:

https://docs.google.com/document/d/1eVvQb4cBt8gw0ufQ-mY4xyObC_vFJeTuunMF945P6xw/edit?usp=sharing

Check out our Demo Videos:
https://youtu.be/Zlwowg_ySd8
https://youtu.be/8GWHmIicdsk
https://youtu.be/YmdMW1OkDuE


Patch suggestions

Envelope:

Patch a gate or trigger output to the start input. Patch the output to any CV
input. Change the position of the ONSET, HEIGHT, and DURATION knobs to create a
corresponding change in the shape of the output CV. Keep in mind that the time
required for ONSET and DURATION to reach their maximum value is from
practically 0 to essentially infinite! You may think this is a problem, but
this ridiculous range is useful when the EVENT is made to perform as a VCO
(described below).HEIGHT controls the voltage level when a gate is held. One
could say it is a "sustain" control, if that is the kind of terminology you
prefer.

ONSET and DURATION can each be controlled in two ways. Obviously the knob
control determines stage length, but there is also a CV input each for ONSET
and DURATION. Additionally, there is another CV input (TRACK) which controls
both ONSET and DURATION inversely. (I know, it's confusing, but we'll get
there. The complexity is what makes it so useful!) A positive change in CV
input on either of the ONSET or DURATION inputs will cause an increase in the
time of that stage. Correspondingly, a negative change will decrease the time.
Now, let's talk about that inverse TRACK input. TRACK is a 1v/oct input (that
can be calibrated somewhat to obtain at least 3 octaves of accurate tuning)
that is inverse to the individual CV inputs of ONSET and DURATION. This means
that an increase in positive voltage will create a decrease in the time of both
ONSET and DURATION. This is useful when we want to use the EVENT as a signal
source. In other words, a VCO.

VCO:

To turn the EVENT into a VCO there are two things that must be in place.
First, take a stacking patch cable and plug in one end to the START input, take
the other end and put it into the PLS DLY output. This creates a loop in the
circuit. When the EVENT output has reached the end of the cycle (the end of the
DURATION stage) a quick pulse is generated. This pulse can be used to recycle
the entire output shape. We now have a variable waveshape VCO, but we have to
initiate the cycle the first time. This where the need for the stacking cable
comes in a trigger, gate, or pulse on either end will start the cycling process
(you can also patch a trigger into the SIGNAL jack if you do not have stacking
cables). Be careful not to ground the tip of the connector if you unplug it
from your trigger source, this will stop the cycle. The output is now a
continuous oscillation, the frequency of which is determined by the ONSET and
DURATION controls, the CV inputs, and the TRACK input. The curious thing about
this VCO is that the shape of the output waveform changes depending on the
setting of the ONSET and DURATION controls and the modulation of their inputs.
Just as before these controls vary the shape of the output by changing the time
it takes to to reach either the peak or trough of the waveform. So, as these
controls are varied, either by the knob or CV, the wave shape changes. Possible
wave shapes are ramp to triangle to sawtooth, or high harmonic content to low
harmonic content (there is another way this can useful when applying a signal
source or CV to the signal input). The Track input proportionately changes the
time for both ONSET and DURATION and does not change the shape of the output as
the voltage is applied proportionally.

SLEW:

A third method of using the EVENT is as a voltage controlled lag processor
whose fluctuations in voltage can be slewed in positive change, negative
change, or both. In much the same way as the other two patching methods changes
are made through knob control or CV input voltages. When using this method of
patching the voltage to be mangled should be applied to the SIGNAL input.



Within the description and patching examples we have outlined here there is
enough to get you started on thinking about how this module can be used. The
EVENT has been named accordingly. By itself, multiple iterations of this one
module can perform every basic function of synthesis. Every detail is not laid
out here. Part of the magic of modular synthesis is discovery, so go play!