Eurorack can seem intimidating at first, but understanding the core concepts is key to unlocking its creative potential. Today, we'll delve into three fundamental signals: CV (Control Voltage), Gate, and Trigger.
1. CV (Control Voltage)
- What it is: CV is an analog voltage signal that controls a parameter of a module. This could be the pitch of an oscillator, the cutoff frequency of a filter, the amplitude of a VCA, or any other controllable parameter.
- How it works: CV signals typically range from -5V to +5V (10V peak-to-peak). 0V often represents a neutral or center point, with negative voltages moving in one direction and positive voltages in the other. Some modules may have different voltage ranges, so always check the manufacturer's specifications.
- Examples:
Pitch CV: Controls the pitch of an oscillator, creating melodies and harmonies.
- Example: Our 3340 VCO features a 1V/octave input, meaning each volt of incoming CV shifts the oscillator's pitch by one octave.
Filter CV: Controls the cutoff frequency of a filter, shaping the timbre of the sound.
- Example: The CV input on our 3320 Low Pass VCF allows for dynamic control over the filter's cutoff. The included "amount" potentiometer provides fine-grained adjustment of the CV signal's influence.
VCA CV: Controls the amplitude (volume) of a signal.
- Example: Our 3360 VCA offers basic CV control over the audio signal's level, allowing for dynamic expression and modulation of volume.
2. Gate
- What it is: A digital signal that indicates the presence or absence of a signal. It's essentially an on/off switch.
- How it works: A gate signal is typically represented by a voltage above a certain threshold (usually around +5V) for "on" and below that threshold (usually around 0V) for "off."
- Examples:
- Triggering envelopes: Gate signals can trigger the attack and decay stages of envelope generators.
- Gating VCOs: A gate can turn an oscillator on and off, creating rhythmic patterns.
- Controlling sequencers: Gate signals can step through the sequence of a sequencer.
3. Trigger
- What it is: A short, sharp pulse that initiates a specific action within a module.
- How it works: Unlike a gate, which can remain "on" for an extended period, a trigger is a very brief pulse, typically lasting only a few milliseconds.
- Examples:
- Retriggering envelopes: A trigger can instantly reset an envelope, creating percussive sounds.
- Starting LFOs: A trigger can start an LFO cycle from its beginning.
- Resetting counters and sequencers: A trigger can reset the position of a counter or sequencer.
Putting it all together:
- CV + Gate: You can use CV to modulate a parameter while a gate signal controls whether the module is active or inactive. For example, you could use a gate signal to turn on an oscillator and then use CV to control its pitch.
- Trigger + Gate: A trigger can be used to initiate a specific action within a module, while a gate signal can control the overall activity of the module.
Key Takeaways:
- CV, Gate, and Trigger are fundamental signals in Eurorack.
- Understanding how these signals work is crucial for patching and understanding how modules interact.
- Experimentation is key! Try different combinations of CV, Gate, and Trigger signals to discover new and unexpected sounds.
This is just a basic introduction to these concepts. As you delve deeper into Eurorack, you'll discover more nuanced uses and interactions between these signals. Happy patching!
Disclaimer: This is a simplified explanation for educational purposes. Always refer to the manufacturer's documentation for specific details and operating instructions for your modules.
I hope this blog post helps you understand these core concepts better! Let me know if you have any other questions.