The 266e Source of Uncertainty provides a general source of musical unpredictability. Operation is divided into four sections, each of which perform a unique function.

Three type of noise are available, with corresponding dedicated outputs. White noise is electrically flat, but acoustically balanced toward the high end of the spectrum ( 3 db/octave). Integrated white noise has a low spectral bias (-3 db/octave). Musically flat noise has a flat spectrum (constant energy per octave) and is a particularly useful source for subsequent processing.

Fluctuating Random Voltages are continuously variable, with voltage control of bandwidth over the range of .05Hz to 50Hz, making possible changes that vary from barely perceptible movement to rapid fluctuation.

Quantized Random Voltages change upon receiving pulses. The number of states is voltage-controllable from two to 24, and their distribution can be varied both spatially and temporally.

Stored Random Voltages have three parameters under voltage control. Degree varies the amount of randomness; Chaos alters the distribution from just a little uncertain to total chaos; Skew biases the randomness toward one extreme or the other.

All settings of the 266e can be stored and recalled under control of the 225e or 206e Preset Manager