The VCF-12 is an advanced 4 pole resonating ladder filter with low pass output. This filter has a smooth characteristic and steep cutoff slope. The frequency can be modulated as well as scaled per keyboard tracking. The VCF-12 can self oscillate at high resonance settings.
The frequency knob changes the cutoff frequency.
The resonance knob controls the amount of feedback in the filter.
The control voltage amount knob applies the CV socket input to the frequency.
The keyboard tracking amount mixes the 1V/oct signal with the cutoff knob amount.
Control voltage input for frequency modulation.
Keyboard note value input in 1 volt per octave.
Low pass output.
24db per octave
20 hz to approx 12 khz
A low pass filter allows frequencies below the cutoff frequency to pass through while attenuating frequencies above the cutoff frequency.
High resonance values will emphasize the filter frequency and slightly reduce the amplitudes of all other frequencies. At very high resonance values, the filter will self oscillate a pure sine wave at the cutoff frequency.
You would typically filter waveforms with lots of harmonics such as sawtooth and square. Filtering a sine wave will have minimal effect.
When the keyboard tracking and cutoff frequency is set to maximum, adding the 1V/oct signal from the MASTER module will allow the filter to self resonate at the same pitch of the keyboard.