CV (Control Voltage) is a type of analog signal used in synthesizers to control different parameters of the sound. It is essentially an electrical voltage signal that is used to control a parameter or feature of a synthesizer module or circuit, such as the pitch of an oscillator, the cutoff frequency of a filter, or the amplitude of a signal.
In an analog synthesizer, CV signals are typically sent between different modules or circuits using patch cables. For example, a keyboard module might generate a CV signal corresponding to the note being played, which would be sent to an oscillator module to control its pitch. A modulation source, such as an LFO (Low Frequency Oscillator), might generate a CV signal that is sent to a filter module to control its cutoff frequency, resulting in a pulsating, rhythmic sound.
One of the advantages of using CV in an analog synthesizer is the ability to create complex and dynamic sounds by modulating different parameters of the sound in real-time. For example, an LFO could be used to modulate the pitch of an oscillator, while another LFO could be used to modulate the filter cutoff frequency, resulting in a swirling, evolving sound that changes over time.
Here is an example of how CV could be used in an analog synthesizer:
- Patch a keyboard module into the CV input of an oscillator module. This will allow the keyboard to control the pitch of the oscillator.
- Patch an LFO into the CV input of a filter module. This will allow the LFO to control the cutoff frequency of the filter.
- Set the LFO to a slow rate and adjust the amount of modulation on the filter cutoff frequency to create a subtle pulsating effect.
- Play a note on the keyboard and listen to the sound. As you hold the note, the pitch of the oscillator will remain constant, but the cutoff frequency of the filter will slowly modulate, creating a pulsating effect that adds movement and interest to the sound.
- Adjust the LFO rate and amount of modulation to create different rhythmic patterns and textures in the sound.
Overall, the use of CV in analog synthesizers allows for complex and dynamic sound creation, and is a key feature of analog synthesis that sets it apart from digital synthesis.
CV and MIDI
CV (Control Voltage) and MIDI (Musical Instrument Digital Interface) are two different methods of controlling synthesizers and other musical instruments. CV is an analog signal that is used to control different parameters of an analog synthesizer, such as the pitch of an oscillator or the cutoff frequency of a filter. It is typically generated by a module in the synthesizer, such as a keyboard module, and is sent to other modules or circuits in the synthesizer using patch cables.
MIDI, on the other hand, is a digital protocol that allows electronic musical instruments and computers to communicate with each other. It consists of a series of messages that are sent between devices, and can be used to control parameters such as note on/off, pitch, velocity, and control change messages. One of the main differences between CV and MIDI is that CV is an analog signal, while MIDI is a digital signal. This means that CV can be affected by factors such as cable length and interference, while MIDI is not affected by these factors. MIDI is also more flexible than CV, as it can be used to control a wider range of parameters and can be sent over long distances using standard MIDI cables or USB connections.
Advantages of CV over MIDI:
- Analog signal: CV is an analog signal, which means that it is more responsive and can provide a more natural and organic sound. It also allows for subtle variations and nuances that can be difficult to achieve with MIDI.
- Tactile control: CV is often preferred by musicians and producers who value the hands-on, tactile approach of analog synthesis. Patching cables and adjusting knobs can provide a more immersive and creative experience than programming MIDI messages.
- Low latency: CV signals can be transmitted with very low latency, making it ideal for live performance and real-time sound manipulation.
Disadvantages of CV over MIDI:
- Limited range of control: CV signals can only control a limited range of parameters, such as pitch, filter cutoff, and amplitude. MIDI, on the other hand, can control a much wider range of parameters, such as velocity, aftertouch, and modulation.
- Limited flexibility: CV signals are often fixed and cannot be easily modified or adjusted on the fly. In contrast, MIDI messages can be easily edited and customized to suit the specific needs of the musician or producer.
- Cable management: CV signals require patch cables to be physically connected between different modules or circuits in a synthesizer, which can be cumbersome and may require additional equipment, such as a patchbay or mult. In contrast, MIDI signals can be sent over a single cable, making it easier to manage and organize connections.
Both CV and MIDI have their own advantages and disadvantages, and are often used together in modern music production. CV is often preferred by musicians and producers who value the tactile and hands-on approach of analog synthesis, while MIDI is often preferred by those who prefer the convenience and flexibility of digital technology. Many modern synthesizers and other musical instruments offer both CV and MIDI connectivity, allowing musicians and producers to use both methods of control depending on their needs and preferences.