"A voltage controlled filter, or VCF, is by definition a filter whose cutoff frequency or center frequency is determined by a control voltage input. Other parameters of the filter (such as resonance) might or might not be voltage controllable, but if the cutoff frequency is voltage controllable, then the filter qualifies as a VCF."@en . "Voltage controlled filter"@en . . . . . . . "A voltage controlled filter, or VCF, is by definition a filter whose cutoff frequency or center frequency is determined by a control voltage input. Other parameters of the filter (such as resonance) might or might not be voltage controllable, but if the cutoff frequency is voltage controllable, then the filter qualifies as a VCF."@en .