One of the simplest yet most potent effects out there is a quick and swift change of frequencies and resonance, and the fact that the Wah pedal brought this ultra-simple yet effective trick to us in treadle format, easily makes it one of the most important devices in effects pedal history. But the filter pedal fest has greatly evolved since then, enabling you to tap into synthetic territories through perfectly tuned low-pass filters, Sample&Hold devices, distorted LFO filters and so much more. So if you want to add great expressive potential to your tone, then you definitely need a filter pedal!