The Brownian LFO offers control voltages that wander as a particle in a glass of water, generally meandering back and forth with idiosyncratic aimlessness along the way. Unlike noise, where each output voltage is independent of the last, Brownian motion is always derived from previous values, creating a more natural, organic change that still offers randomness.
Adding a little bit of width to the Brownian LFO module, the “+” is for the extra modulation options, allowing you to modulate the modulation (perhaps with other Brownian LFOs) for interesting changes in rate, effect size, and effect ranges. The SIZE control sets how big a random variation can get and modulating it lets you decide how often larger variations can occur. The TIME control determines the frequency of random variations and modulating it allows you to create a mixture of quick and longer changes, which is useful for tape-like flutter effects. GLIDE is used for smoothing and modulating it is a great way to balance jagged changes with smooth transitions. The two BOUNDS dials set the upper and lower limits of voltage swings and they are modulated together, increasing and decreasing around a center voltage with the SPREAD control specifying the range between these boundaries. A handy MOD button can be flipped to stop modulation to calm things down while you’re working. The RECENTER jack accepts trigger pulses to push the voltage back toward zero so that you can specify moments where you’d like the device to be neutralized.
Where the Brownian LFO provides wandering oscillations for control voltages, the Brownian LFO+ adds a host of modulation options to create additionally complex movements, well-controlled types of randomness that can dynamically change with the music, and opportunities for serendipitous discovery.
If you already own the Brownian LFO, you’ll find this module discounted by the full price of that module (as if it were free).