Changes

Many others have popped up that mimic the basic design of the ''Tube Screamer'' but tweak certain component values, making some strong changes to the tone. The basic principle is to use a high-pass filter to remove some low end and "tighten" the tone, while using a low-pass to trim some extreme highs, and a variable band-pass to dial in the resonant peak that defines the distortion tone. However, the ''Tube Screamer'' is almost always the basis of comparison, due to its high name and tone recognition.

Various ''treble booster'' pedals were quite popular in the 60's and 70's and remain popular for vintage sounds. These typically provided a high-pass or high-shelf filter with a variable gain and frequency. While I find these nice for a "quick and dirty" approach to dialing in a distortion tone, I prefer to use EQ or a distortion pedal where I have more tone-shaping control.