ADDAC 507 Random Bezier Waves
Two channels of smooth random control voltage, with Bezier curves doing the smoothing.
Overview
The ADDAC 507 Random Bezier Waves is a Eurorack module with two fully independent channels of smoothed random control voltage. Each channel puts out bipolar voltages that glide between points using Bezier curve interpolation. Instead of linear ramps or stepped jumps, you get curves that feel natural, almost biological. The modulation keeps evolving rather than just changing.
The 507 sits between an LFO and a random voltage generator. Both channels are identical and interconnected, so you can create feedback loops, cross-modulate parameters, or average their outputs. None of that needs a patch cable beyond your power bus. It gives usable results even with a basic setup.
It drifts, pulses and folds without demanding attention.
Specifications
| Manufacturer | ADDAC (ADDAC System) |
| Product Type | Eurorack Module; Two-channel modulation source for random control voltages |
| Power Requirement | 70 mA (+12 V) / 40 mA (-12 V) |
| Width | 10 HP |
| Depth | 45 mm (4.5cm) |
| Outputs per Channel | Wave output, inverted wave output, and gate output |
| Additional Outputs | Two averaged outputs (AB Average and Inverted Average) |
| Parameters per Channel | Frequency, Level (VCA), Offset (+/-5V), Curve (form of interpolation) |
| Per Channel Toggle Switch | Limit/Fold/Thru |
| Per Channel Controls | LED displays and CV inputs with attenuators for frequency and level |
Key Features
Smooth Random Generation with Bezier Curves
Each channel on the ADDAC 507 is a complete smooth random voltage generator. Instead of jumping or ramping linearly between random points, it uses Bezier curves for the transitions. The "Curve" parameter adjusts the shape of this interpolation, so you control how the voltage moves from point to point, from a gentle arc to something more dramatic.
Interconnected Dual Channels
The two channels talk to each other. When you leave the CV inputs for Frequency and Level unpatched, they are internally connected to the main output of the opposite channel. Channel A can modulate Channel B's speed and amplitude, and vice versa. That gives you self-generating, evolving feedback patches right out of the box, with no external modulation source.
Smart Gate Outputs with Different Personalities
The gate outputs on the two channels work differently. Channel A's gate fires a pulse every time a new random value is generated, which suits triggering envelopes or sequencing events in time with the voltage shifts. Channel B acts like a comparator: it outputs a high gate whenever its main output is positive. That gives you rhythmic patterns based on the polarity of the waveform.
Flexible Output Options and Visual Feedback
Besides the main and inverted wave outputs on each channel, the module has two summed outputs: AB Average and Inverted Average. These blend the two channels into a single, more complex control voltage, handy for modulating a filter cutoff or pitch. LED displays show both bipolar activity and gate behavior, so you can watch the randomness as it happens.
Offset, Attenuation, and Signal Shaping
Each channel has an Offset control that shifts the whole voltage range up or down within a ±5V window, so you can match the random signal to the destination module. The Level control works as both an attenuator and a VCA, scaling the output from full amplitude down to silence. CV inputs for both Frequency and Level each have their own attenuators. You can modulate the module externally or let it run on its own.
Historical Context
The ADDAC 507 Random Bezier Waves started as an idea from Rijnder Kamerbeek, better known as Monotrail, a YouTuber and modular enthusiast. His idea was a straightforward random generator that interpolates between points using smooth curves, effectively a complex, ever-evolving LFO. ADDAC System built it as part of their ADDAC500 Series. No broader historical context or market timing has been documented beyond this collaboration.
Collectibility & Value
The ADDAC 507 is currently available new from retailers at €245.08 (excluding VAT). No original MSRP or production years have been confirmed. There is no documented data on common failures, maintenance issues, or long-term reliability. Collectibility is driven more by utility than scarcity.
One user review reads: "Slow Random Voltages kann man sich auch selbst basteln… oder man benutzt ADDAC 507 Random Bezier Waves. Zwei, drei schnelle Einstellungen und der Käse ist gelutscht." (Translation: "You can build slow random voltages yourself… or you just use the ADDAC 507. A couple quick settings and the job's done.") The reviewer goes on to say the Bezier interpolation produces "weichere Übergänge" (softer transitions) than traditional methods, concluding: "Wer leistungslos bessere Ergebnisse erzielen will, als mit viel Fummelei, ist hier bestens bedient. Ich liebe das Teil." ("If you want better results with less effort, you're in good hands here. I love this thing.")
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