Review: Bram Bos Ripplemaker

A semi-modular softsynth with a nod towards Buchla
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As the developer behind several impressive software synthesizers, Bram Bos’s iOS apps are quickly developing a cult-like following among iPad-based producers, thanks to his devotion to modeling actual circuit behavior.

Ripplemaker provides the flexibility of a hardware modular synthesizer, with a nod toward classic Buchla and Serge features.

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Ripplemaker is the perfect introduction to West Coast-style modular synthesis, with its approach to waveshaping and semi-additive tools. Bram wisely focused on core modules of the idiom, which lets newcomers quickly test out patching ideas without getting lost in the details. And the architecture is semi-modular, with a prepatched signal flow that can be modified via virtual patch cables. Let’s examine each module individually.

Oscillator: Ripplemaker’s oscillator is a great way to get a handle on the essentials of West Coast synthesis. It’s based on a triangle core, which can be continuously swept between triangle and square wave-shapes. From there, it hits the Fold circuit, where it is clipped; the folded part of the wave is inverted and added back to the signal, which introduces bright, FM-like harmonics to the waveform. Another cool West Coast feature is a Push function that applies DC offset to warp the waveform further. It’s remarkable to hear the tonal range of this oscillator in an iOS app.

Slope: Fans of so-called East Coast synthesis will look at this as a simple AD envelope generator. However, hitting the Cycle button allows Slope to be used as an oscillator—either as an LFO or at audio rates—with attack and decay controlling the shape and depending on how the CV is configured.

Lowpass Gate: Unlike mainstream resonant filters, Ripplemaker incorporates a Buchla-style lowpass gate that can smoothly morph from a VCA to a conventional lowpass filter (with a very slight resonant boost for emphasis). In addition to the Gate:Filter balance knob, there are controls for cutoff frequency and a bandpass switch for creating squelchier effects.

Noise S&H: This module is a sample-and-hold circuit based on a noise generator as its input. At rates below 100%, it generates the traditional randomly stepped voltages. At maximum speed, it functions as a white noise source.

Envelope: This will be the most familiar module for many users and includes a standard ADSR envelope with dual outputs for modulating multiple destinations.

LFO: The LFO is fairly standard, providing triangle and square outputs and a width knob that functions mainly as an attenuator for the output.

Amp/Delay: In addition to VCA features and voltage control, the amplifier section also includes a basic delay with level, time and feedback controls. Surprisingly, the time can’t be voltage-controlled, which isn’t necessarily a bad thing; it’s just unusual in the context of Ripplemaker’s overall architecture.

Utilities: In addition to all of the above modules, Ripplemaker also includes a pair of attenuators that can add or multiply the input sources, as well as provide summing, splitting, and scaling. You can also set a constant voltage for more unusual applications.

Ripplemaker is compatible with CoreMIDI, AudioBus 3, Ableton Link and AudioUnits, so it plays well with other iOS products. It also includes an integrated step-sequencer, so you can focus on your patches while a pattern is playing. For nine bucks, Ripplemaker is a compelling app and a fine intro to the world of West Coast-style modular synthesis.

Supports AUv3, AudioBus 3, and Ableton Link. Authentic modeled circuit behavior.

No CV for delay time.


Producer Francis Prève has been designing synthesizer presets professionally since 2000. Check out his soundware company at