dBu

Manufacturers use dBu to state input sensitivity, nominal and maximum input and output levels, threshold ranges, noise floors, and distortion test levels¹²³⁴⁵. For example, a pedal may list a nominal input level of -20 dBu, a maximum output level of +10 dBu, or a residual noise level of -93 dBu⁴¹³⁶. In a rig, these figures describe how signal levels at a pedal's inputs and outputs are measured and rated⁷⁸.