SF1 Dual / Stereo Filter

Dual linkable VCF with multiple responses and voltage controlled panner/crossfader output

SF1 is a dual voltage controlled filter (VCF) module designed to be used either as a pair of identical, but separate VCFs, or as a stereo filter, accepting its input as 2 mono (L/R) inputs through standard 3.5mm TS connections.

The core of SF1 is a 4-pole voltage-controlled lowpass filter which uses precise “pole-mixing” to provide a multitude of outputs from each filter. Each filter has TWO outputs which are available concurrently. The first set of outputs (L1/R1) may be selected to output Low Pass, High Pass, or Band Pass responses. At each one of these selections, the cutoff curve may be selected between “2 pole” (12 db/octave) or “4 pole” (24 db/octave).

The second set of outputs (L2/R2) may be selected to output a single pole Notch, 2 pole All-pass, or 4-stage Phaser response.

Finally, each pair of outputs (L1/R1 and L2/R2) feeds into a set of 2 voltage controlled crossfaders which may be used to modulate the amount of panning between the 2 sides of SF1.