centrevillage PLLVCO

MUSICAL FEATURES

PLLVCO is a module that combines a Phase Locked Loop (PLL) circuit with an analog oscillator.

The PLL circuit allows for pitch control not only using the common V/Oct method, but also by controlling the oscillator's pitch to a rational multiple (N/M) of the frequency of an external oscillator input to the PLL.

This allows you to control the frequency of an internal oscillator to 3/2 times the frequency of an externally input oscillator, and then mix those two oscillators with an external mixer to create an oscillator that produces chords overlapping by a perfect fifth.

Furthermore, when an external audio signal is input to the PLL input, the pitch of the input audio is detected and output as a V/Oct voltage from the FRQ output. This allows for interesting applications, such as inputting vocals or guitar sounds as the external audio source and controlling the pitch of another, more complex oscillator from the FRQ output. (However, it may not detect chords or complex harmonics well.)

The pitch tracking speed of the PLL circuit can be adjusted using the SENS slider. However, at high tracking speeds, phase distortion occurs in the waveform, resulting in a tonal change similar to oscillator sync. Therefore, the SENS is usually set to a speed that does not produce phase distortion.

The frequency range can be set to either a VCO or an LFO. When set to an LFO, it can be used as a clock-synchronized LFO. In this case, as with the VCO, it can oscillate at a speed that is a rational number of times the input clock, so it can be used as a clock divider or multiplier.