Maestro Parametric Filter

The Maestro Parametric Filter, more commonly referred to as the "Coltrane Box" in my little world, is an old guitar effect I've used for more than 20 years. I could educate you with a bunch of technical jargon that means nothing to me, or I could tell you about all the times I've stomped on that noisy old beast and let the midrangey wash elevate my rudimentary, fuzzed out pentatonic scales to new heights.