What is crossover distortion?
Crossover distortion is caused when a Class AB amplifier is biased too “cold.” Instead of the power tubes biased so that each half of the alternation is put back together to form a full sine wave, there are “gaps” between the alternations, which form a “broken” sine wave. The gaps between each alternation can be heard by the guitarist, and are interpreted as unpleasant high odd order harmonics by the brain. Note that the crossover distortion in the picture is exaggerated for educational clarity.
