Expand the functionality of your synth with the Erica Synths Highpass VCF Voicecard, an expansion card for the Bullfrog synthesizer that expands the sound treatment capabilities of the instrument by bringing a high-pass voltage-controlled filter into the mix, allowing for the exploration of high-pass and bandpass filtering under CV control.

The voice card features typical VCF controls including cutoff frequency, resonance, and CV level. The CV source switch allows for selecting between three CV sources (envelope generator 2, Sample & Hold, or LFO). The voice card features internal audio connections that pass the signal from the output of the mixer into the highpass VCF, which outputs to the low-pass VCF and VCA. For more flexibility, no CV connections for the Bullfrog are present on the voice card, so you have to do the patching yourself.