One of the most-argued gain pairings on a pedalboard. The Rat is a hard-clipping distortion with a lot on tap; the Tube Screamer is a lower-gain, mid-humped overdrive that pushes an amp. They are not really the same class of pedal — one distorts, the other drives.
| ProCo Rat | Tube Screamer | |
|---|---|---|
| Gain type | Hard clipping (diodes to ground) — grittier, more aggressive, more gain available. | Soft clipping in the op-amp feedback loop — smoother, lower-gain, amp-like push. |
| Tone shape | Its Filter knob rolls off treble as you turn up — can go dark and thick or bright and cutting. | Fixed mid-hump: pushes mids forward and tightens the low end. |
| Gain range | Mild overdrive all the way to full fuzzy distortion — very wide. | Low–medium; really shines as a boost into an already-dirty amp. |
| Best at | Standalone distortion, gritty leads, thick rhythm — works on a clean amp. | Tightening a high-gain amp, blues-rock lead, cutting through a band. |
| Famous for | Jeff Beck, Radiohead, early Metallica rhythm, grunge grit. | SRV, metal rhythm tightening, countless blues records. |
They do different jobs. A ProCo Rat is a hard-clipping distortion with lots of gain and a Filter knob for darkness — it makes its own dirty sound even on a clean amp. A Tube Screamer is a lower-gain overdrive with a fixed mid-hump that tightens and boosts an amp that is already breaking up. Pick the Rat for standalone distortion, the Tube Screamer to push a dirty amp.