What Is a Voltage-Controlled Amplifier?
A voltage controlled filter (VCF) is a processor, a filter whose operating characteristics (mainly the cutoff frequency) can be controlled by a control voltage applied to the control input. It can be thought of as a frequency dependent amplifier. Although generally known for their use in analog music synthesizers, they have other applications in military and industrial electronics. [1]
- VCF allows its cut-off frequency and Q factor (resonance at the cut-off frequency) to be continuously changed; the signal output can include low-pass response, high-pass response, band-pass response and notch response. The filter can provide a variable slope that determines the rate of attenuation outside the bandpass, typically 6dB / octave, 12dB / octave ('2-pole' filter) or 24dB / octave ('4-pole' filter) Device). This also varies by Q.
- In a modular analog synthesizer, a filter receives signal inputs from a signal source, including oscillators and noise, or outputs from other processors. By changing the cutoff frequency, the instrument passes or attenuates the part.
- "Filter scan" has become a common effect in some popular electronic music styles. These scans are created by changing the cutoff frequency of the VCF (sometimes very slow). Cut-off is controlled by transient voltage control (such as an envelope generator), especially with relatively fast attack settings that can simulate attack transients from natural or acoustic instruments.
- Historically, VCF includes variable
- Introduced
- Electronic filter
- Nonlinear filter
- Self-oscillation
- Subtraction synthesis
- Voltage controlled amplifier
- Voltage controlled oscillator