The Buchla 266 Source of Uncertainty Classic Reissue is a recreation of the iconic random voltage module of the original 200 series.

The Buchla 266 Source of Uncertainty is a random voltage generator using two continuously fluctuating random voltages, two pulse-actuated voltages, and audio noise with three spectral distributions and a specialised sample and hold function.

A wide range of voltages can be controlled by varying the amount from 0.05 to 50 Hz. Changes can vary from barely perceptible to rapid movements.

Voltage controllable varying random voltages have a bandwidth (probable rate of change), which allows for changes ranging from barely perceptible movements to rapid fluctuation.

A constant voltage is output from each random voltage source. This constant voltage changes with each pulse input. A variable correlation limits successive changes while maintaining range.

The three flavours of noise are white noise, integrated white noise, and musically flat noise. White noise is electrically flat, but acoustically balanced towards high frequencies (+3dB/Octave) while integrated white noise has a low spectral bias (-3dB/Octave) and Musically flat noise features a flat spectrum with constant energy per octave.

The Source of uncertainty model 266 Buchla module includes voltage control over probability distribution and quantisation, integrator and a specialised sample and hold.