Five Oscillators That Refuse to Choose Between Audio and Control
Most oscillator banks are content to generate audio signals and leave modulation to dedicated LFO modules. But Crows Electromusic’s Ovum Eurorack—the modularized evolution of their 2023 desktop drone synthesizer—operates from a more flexible premise. Each of its five analog triangle-core oscillators can switch between audio-rate oscillation and slow modulation duties, creating a module that’s simultaneously a drone synthesizer, LFO bank, or hybrid combination of both.
This Vancouver-built module transforms the straightforward charm of the original Ovum desktop unit into a modular powerhouse that adapts to whatever your patch demands. At $149 USD for 20HP, it delivers five analog oscillators with the kind of versatility that makes small modular systems surprisingly capable.
From Desktop to Rack: Evolution Through Modularization
The original Ovum established itself as a compelling drone synthesizer with minimal controls but maximum character. Five oscillators, simple pitch controls, and straightforward mixing created an instrument that proved less can indeed be more when the less is carefully chosen.
The Eurorack version preserves that essential simplicity while adding the flexibility that modular integration demands. Each oscillator gains individual switching between audio and LFO rates, individual outputs, and proper Eurorack voltage levels. It’s the same core concept, refined for modular workflow.
Five-Oscillator Architecture: Audio or Modulation on Demand
The heart of the Ovum Eurorack remains its five analog triangle-core oscillators, each with dedicated controls for pitch, level (via slider), and wave shape morphing from bright square to crisp triangle. But the crucial addition is the per-oscillator audio/LFO switch that transforms each voice’s role on demand.
Oscillator Specifications:
- Five analog triangle-core oscillators
- Individual pitch, level, and wave shape controls per oscillator
- Audio/LFO switch for each oscillator
- Wave shape morphing from square to triangle
- 10Vpp output level (+/-5V) per oscillator
- Individual outputs normalled to main mix output
- 20HP Eurorack format
- Hand-built in Vancouver, Canada
The individual switching capability means you can configure the module as five audio oscillators, five LFOs, or any combination in between. Need three drones and two modulation sources? Switch three to audio rate and two to LFO rate. The flexibility is immediate and intuitive.
Triangle Core Character: Analog Warmth with Digital-Like Precision
Triangle-core oscillators offer a unique sonic character that bridges the gap between the warmth of analog circuits and the precision of digital waveforms. The triangle wave provides a pure fundamental with minimal harmonic content, while the square wave morphing adds harmonic richness and brightness control.
This waveform selection proves particularly effective for drone applications, where pure tones can create beating patterns and harmonic relationships that evolve slowly over time. The morphing capability allows real-time adjustment of harmonic complexity without losing the core drone character.
Normalization Intelligence: Individual Control, Collective Output
The Ovum’s output normalization scheme reflects smart modular design thinking. Each oscillator has its individual output, but these are normalled to the main mix output on the right side of the module. This means you can use the module as a five-oscillator voice with mixed output, or break the normalization by patching individual oscillators to separate destinations.
This approach maximizes flexibility while maintaining simplicity. Leave everything unpatched for a classic five-oscillator drone, or patch individual outputs for complex polyphonic applications, modulation distribution, or hybrid audio/control voltage scenarios.
LFO Capabilities: Slow Motion Analog Modulation
When switched to LFO mode, each oscillator becomes a slow modulation source with the same wave shape morphing capabilities available at audio rates. Five independent LFOs with shape control and individual outputs provide substantial modulation capability for complex patches.
The analog nature of these LFOs means they have the subtle timing variations and harmonic content that make analog modulation feel alive compared to digital alternatives. Use them for filter sweeps, amplitude modulation, pitch variations, or any parameter that benefits from slow, organic movement.
Hybrid Applications: The Best of Both Worlds
Perhaps the most interesting applications emerge when using the Ovum in hybrid configurations—some oscillators at audio rate, others providing modulation. Two oscillators creating drone tones while three others modulate filter cutoffs, VCA levels, and effect parameters creates complex, evolving soundscapes from a single module.
This hybrid approach is particularly effective for ambient and experimental music, where the boundary between pitched content and modulation often blurs. The Ovum makes these blurred boundaries easy to explore and musically useful to exploit.
Hand-Built Quality: Vancouver Craftsmanship
The hand-built construction in Vancouver reflects Crows Electromusic’s boutique approach to module manufacturing. Each Ovum receives individual attention during assembly, ensuring quality control that mass production can’t match.
At $149 USD, this hand-built approach represents exceptional value, especially considering you’re getting five analog oscillators with switching capabilities and individual outputs. Compare this to the cost of separate oscillator and LFO modules, and the Ovum’s value proposition becomes compelling.
Integration Suggestions: Building Around the Ovum
The Ovum works particularly well as a foundation module for drone-focused systems. Add a colorful multimode filter, some effects processing, and basic mixing capabilities, and you have a complete drone synthesizer that can also provide modulation for more complex patches.
The 20HP footprint is substantial but reasonable for five oscillators with this level of functionality. In smaller systems, the Ovum can serve as both primary sound source and modulation provider, reducing the need for multiple dedicated modules.
Missing Features: Room for Evolution
The lack of frequency modulation (FM) between oscillators represents a missed opportunity for even more complex harmonic relationships. As noted in the first impression, this feature could appear in a future Mk2 version and would significantly expand the module’s sonic possibilities.
Similarly, CV control over pitch and wave shape morphing would increase the module’s integration with other modular components. These aren’t critical omissions, but they represent logical evolution paths for future versions.
European Distribution: Reverb.com Integration
The use of Reverb.com’s official store for European orders reflects smart distribution strategy for a small manufacturer. This approach provides European customers with familiar purchasing processes and reliable shipping while allowing Crows Electromusic to focus on design and manufacturing.
Value Proposition: Five Oscillators, Endless Possibilities
At $149 USD, the Ovum Eurorack delivers exceptional value for analog oscillator functionality. Five triangle-core oscillators with wave shaping, individual outputs, and audio/LFO switching provide capabilities that would cost significantly more if purchased as separate modules.
The hand-built quality, boutique character, and Vancouver craftsmanship add intangible value that mass-produced alternatives can’t match. You’re not just buying functionality—you’re investing in a unique take on oscillator design from a creative small manufacturer.
The Drone Evolution
The Ovum Eurorack represents successful evolution from desktop instrument to modular component. By preserving the essential character of the original while adding modular-specific functionality, Crows Electromusic has created something genuinely useful rather than merely adapted.
Whether you’re building a dedicated drone system, need substantial modulation capability, or want analog oscillator character at an accessible price point, the Ovum Eurorack offers a compelling combination of simplicity and flexibility.
Ready to let five oscillators shape your modular destiny? The Crows Electromusic Ovum Eurorack at $149 USD proves that sometimes the best evolution is knowing exactly what to change and what to preserve.
About Me
Hi, I’m Canoy Dang. I grew up in Granada and now living in Málaga, in the south of Spain. Sound has always played a central role in my life — from early home recordings to the deeper, ongoing exploration of the modular synth world. Modular, semi-modular, and desktop synthesizers have become my main tools for expression, experimentation, and sometimes, simply for getting lost in the process.
