The A-149-1 is based on Don Buchla’s “Source of Uncertainty” modules, and has four analogue random CV’s that are generated in different ways. The “Quantized Random Voltages” have 2 CV outputs: “N+1 states” and “2N states”. N is in the range of 1...6 and can be manually adjusted or by external control voltage with attenuator.
When the rising edge of the input clock a new random voltage is generated at N+1 and 2N output. The N+1 output generates N+1 different voltage levels, the 2N output up to 2N different states. If for example N is set to 4 the N+1 output generates up to 5, the 2N output 16 different states.
The voltage steps are exact semitones when used with a VCO. Even the “Stored Random Voltages” section have 2 stepped CV outputs available: one with even voltage distribution of the max. 256 output states and a second one with adjustable voltage, adjusted by a manual control and an external control voltage with attenuator. With the control set at minimum, most of the random voltages will be low magnitude but even medium and high magnitude voltages may appear but with smaller probability. As the control is turned up (or a positive control voltage appears at the CVD input) the distribution moves through medium to high magnitude voltage probability.
The A-149.1 can be extended by 8 random digital voltages with the A-149.2 Digital Random Voltages module