Product Overview
The FilterFX project uses the Druid STOMPLFO to control a 12dB/oct state variable filter. A state variable filter (SVF) is chosen because this filter design offers highpass, bandpass, and lowpass outputs which gives us the greatest range of different effects. The LFO offers eight waveforms, including two random waveforms (one does those crazy sample-and-hold effects like the Maestro FSH-1).
Furthermore, the PCB provides for addition of an expression pedal to allow the filter to be used like a wah pedal (but don’t expect a replacement for your Clyde McCoy – this is a whole different thing!). The expression pedal can be used as well as the LFO modulation, or with Depth at zero, by itself. The Expression pedal input can also be used with a 0-5V CV. There is also a Sync input for the LFO which allows the LFO to be kept in time with an external clock from a sequencer, drum machine, or another LFO. In many ways, this is a modular synth filter in a stompbox, and it can sound like it, too – there’s a distinctively “synthy” element to the sound with this one.
A PCB for the FilterFX 12dB/oct SVF project. This PCB is designed to fit into a Hammond 1590BB enclosure in landscape format, and can be used with PCB mounting pots for a simple, reliable construction.
The PCB is FR4 fibreglass for strength, with plated through-holes and green soldermask and white screen print on both sides. The PCB layout can accept film capacitors with either 5mm/0.2″ or 7.5mm/0.3″ lead spacing, so you’re not limited in your choice of capacitors.
You might find it easier to order the FilterFX PCB + parts set, which includes the two vactrols, the two unusual On-On-On DPDT switches, and the Druid StompLFO chip.
