RAT
Hard clipping to ground, and a tone control that runs backwards.
Hard clipping to ground
Diodes after the gain stage shunt anything above their threshold straight to ground, so the waveform is sheared off flat with a corner on it. Same idea as soft clipping, applied in a different place, and the corner is the audible difference.
- In
- Out
Drawn to illustrate the description above, not measured from a specific unit.
What the circuit does
An op-amp gain stage with a very large available gain, followed by silicon diodes clipping to ground. Clipping after the stage rather than inside its feedback loop squares the waveform off far more abruptly than a Tube Screamer does.
What to listen for
A flatter, harder edge than a soft-clipping drive, and a lot more gain on tap at the top of the dial. The Filter control is a reversed tone: turning it up rolls treble off, which catches out everyone who meets one for the first time.
Where it goes
The overdrive and distortion slot
After the fuzz and before everything time based. Distorting a signal and then delaying it keeps the repeats clean; delaying a signal and then distorting it drives the repeats and the dry note together into one smear.
Controls
- Distortion
- Filter
- Volume