sag

Sag is a softening, compressed response associated with tube amps and reproduced by some pedals, often described as tube-like or amp-like¹². It appears at high gain as authentic tube breakup alongside compression³⁴, and in overdrives it makes lead lines sing while single notes bloom with sustain¹⁵. Some pedals offer a Sag or voltage-sag control that lowers voltage below 9V, producing glitchy, sputtery, dying-battery or Velcro-like fuzz sounds⁶⁷⁸. Sag emulation can also impart a vintage flavor with strong note-to-note clarity and an expressive response⁹.