The Distortion/Overdrive effect can do everything from tape saturation, to vacuum tube type overdrive, to transistor type hard clipping distortion.
Effect Variation - The type of distortion. Overdrive, Distortion, Saturation, Foldback, Flipover, Wraparound and Exponential.
Input Gain - The amount of gain applied to the input signal. The LED shows when it is over 0 dB.
Shape - The amount the signal is distorted. The Input Gain also effects the amount of distortion. Note: the name changes depending on the type of distortion.
Bias - The distortion symmetry. For symmetrical (odd harmonics only) or asymmetrical distortion.
EQ - The amount of boost or cut to the low, mid and high frequency bands.
Cabinet Resonance - The amount of cabinet resonance.
Cabinet On/Off - Switches the cabinet simulator on or off.
Cabinet Size - The size of the cabinet.
Output Gain - The amount of gain applied to the output signal. The LED shows when it's over 0 dB.