Guitar Pedal X - GPX Blog - A Brief Hobbyist Primer on Key Tone Stack Types and Circuit EQ Configurations - in collaboration with Master-Builder Adrian 'Thorpy' Thorpe
Second Hand Amp Tweaker Defizzerator Passive EQ Pedal w/box - - Andertons Music Co.
Anyone here ever use one of these ? Ayan Smooth and Slim passive EQ | The Gear Page
Passive 3 band EQ
SMALL FI 4 BASS CUT LO FIDELITY EFFECT PEDAL PASSIVE EQ HIGH PASS FILTER LOW | eBay