Overdrive

The Speaker Cranker™ is a discrete, all-analog distortion enhancement device (i.e., not a booster), designed to give your signal some extra grit and a slight boost without drastically altering your tone. Think of it as sticking an extra preamp tube in your amplifier for more overdrive.

Single notes will blossom and bloom with rich harmonics and responsive, tube-like sag. Power chords will sound thicker and crunchier, a little more ragged around the edges. Complex chords will remain distinct and complex, as the Speaker Cranker is designed to preserve your tone’s integrity without muddying up the low-end, or “rounding out” the mids, or adding any top-end “shimmer,” or “sparkle,” or any of that other garbage. It’s your tone. Cranked. Ya got that?

Repeat after me: “The Speaker Cranker is an overdrive, not a boost.”

https://www.earthquakerdevices.com/speaker-cranker