Doepfer A-149-3 Fluctuating Random Voltages

The Doepfer A-149-3 is a deep, modular reimagining of Buchla’s classic "Fluctuating Random Voltages" concept from the Source of Uncertainty. Going beyond imitation, this module offers four internally linked but independently usable sections: filtered noise, a noisy triangle LFO, sample & hold, and a vactrol-based slew limiter.

Three distinct digital noise flavours—Blue (+3dB), Red/Brown (–3dB), and Pink (Flat)—feed the Noisy Triangle generator, which combines an adjustable LFO with noise to produce lively, fluctuating voltages. This in turn is normalled into the sample & hold circuit, which includes a built-in clock with LED indicator and smoothing feedback (labelled Correlation). The final stage is a CV-controllable slew limiter with manual and modulated control over rise/fall time via a vactrol.

Whether you use the sections together to generate complex random voltages, or patch each one independently, the A-149-3 delivers a flexible and musical approach to West Coast-style unpredictability.

Key Features

• Inspired by Buchla’s Source of Uncertainty (265/266)

• Three digital noise outputs: Blue (+3dB), Red/Brown (–3dB), and Pink (Flat)

• Internal triangle LFO with frequency and range control

• Noisiness control blends LFO with selected noise source

• Noisy Triangle output for modulated fluctuations

• Sample & Hold circuit with internal or external clock

• Clock LED indicator and adjustable clock period

• Correlation control adds smoothing to S&H output

• Vactrol-based slew limiter with CV input and attenuator

• Manual Slew time control and normalled signal routing

• LED indicators for all key outputs and modulation activity

• Available in-store for demo