A concept in which a basic parameter of a sound producing or processing component can be taken down to zero and then into negative values, and the component will do something sensible with the transition. A basic example is that of the ring modulator, which can be regarded as a VCA capable of both positive and negative gain (see Four quadrant). When the ring modulator is in the negative gain range, it amplifies the input signal according to the absolute value of the gain, but the output is inverted.