midiphy zetaSID: Expandable 4HP SID Eurorack Module

The midiphy zetaSID introduces a compelling new Eurorack modular synthesizer voice, reimagining the iconic SID chip from the Commodore 64. This compact 4HP module is designed to integrate the legendary sound of the 1980s into modern modular setups. Leveraging the robust MIDIbox SID synthesis engine, the zetaSID offers an extensive array of sound design tools, making it a versatile addition for electronic music producers. Moreover, its innovative design allows for significant expandability, ensuring it can adapt to various production needs and scales. This module represents a powerful fusion of vintage sound and contemporary modular flexibility.

Core Synthesis Engine and Features

At its heart, the zetaSID boasts a powerful synthesis engine derived from the MIDIbox SID. This includes six LFOs, dual envelopes with multi-stage attack, decay, and release phases, and flexible curve shape control. Furthermore, it features quad wave sequencers, which are instrumental for animating sound progression over time. Producers can also utilize eight modulation paths with dozens of sources, algorithmic operations, and an extensive 24×14 event trigger matrix for intricate sound design possibilities. For percussion, the module includes a Drum sound engine with up to 16 parallel instruments, offering 19 parametric drum algorithms ranging from bass drums and snares to classic C64 sound effects, capturing the distinctive percussive joy of that era. Similarly, the Lead sound engine provides vast options for melodic and textural synthesis.

Expandability and Polyphony via phybus

One of the zetaSID’s most notable features is its expandability through the midiphy phybus system. While a single unit functions as a monophonic voice controlled via CV/gate, integrating a nexusMIDI phybus expansion module allows for simplified polyphonic use, transforming it into a conventional MIDI synthesizer. In addition, users can chain up to twelve zetaSID modules in a phybus instrument cluster, achieving six polyphonic stereo voices. The system also supports ASID SID-file playback via MIDI. When expanding, unused CV and gate inputs can be repurposed as additional modulation sources, enhancing the module’s flexibility. This modular approach ensures that the zetaSID can grow with a producer’s needs, offering scalable power.

Intuitive User Interface and Sound Design

Despite its compact 4HP size, the zetaSID features an intuitive graphical user interface with a vibrant OLED display. This display provides fluid visualizations of oscillator outputs, arpeggio patterns, and filter curves, significantly reducing the need for deep menu diving. In fact, the user interface is designed for cooperative use; multiple zetaSIDs can be dedicated to different configuration tasks within a shared polyphonic SID sound engine patch. For instance, one module could adjust the filter, another could reconfigure LFO rates, and a third might manage the event trigger matrix. This unique cooperation model allows for a hands-on approach to sound design, dedicating a knob or button to specific patch sections. The module ships with 100 carefully crafted patches in its ROM bank, providing immediate inspiration and starting points for new creations.

Advanced Sequencing and Compatibility

The zetaSID integrates advanced per-oscillator arpeggiators, each with individually configurable and syncable clock speeds. These powerful arpeggio parameters are perfect for creating classic chiptune sounds, from slow sequences to high-speed multi-octave performances. Additionally, the integrated quad wave sequencer, based on original C64 sound generation techniques (unrelated to modern wavetable synthesis), enables step-wise modulation of SID patch parameters. This includes fine-grained adjustments of oscillator pitches over time using absolute or relative sequencer values for each step. Four wave sequencers per patch are available, each with individually configurable playback speeds. Therefore, complex rhythmic and melodic patterns are easily achievable. The module also offers limited compatibility with existing community MBSID v2 Lead and Drum patches, which can be stored and loaded in their original SysEx file format, though a microSD card is required for this functionality and for saving/recalling sessions.

Features

One of the world’s most powerful SID sound engines, based on MIDIbox SID, with six LFOs, eight modulation paths, two envelopes, and four integrated wave sequencers.
Drum sound engine with up to 16 different parallel instruments and 19 parametric drum algorithms.
Rack-space-saving 4HP minimalism with an intuitive graphical UI and fluid visualization.
Integrated ROM bank with 100 preset patches.
State-of-the-art SID sound chip emulation for noise-free sounds.
Stereo sound engine design and stereo voice polychaining for up to six polyphonic stereo voices.
Multi-SID unison mode for fat unison sounds.
User interface expansion via phybus UI cooperation.
Integrated advanced per-oscillator arpeggiators with configurable clock speeds.
Integrated quad wave sequencer for step-wise modulation of SID patch parameters.
Optional MIDI expansion with nexusMIDI.
Patch virtual cords between midiphy modules using phybus for reduced cable clutter and total recall (microSD card required).
Limited compatibility with existing community MBSID v2 Lead and Drum patches.

zetaSID Technical Data

Width: 4 HP
Depth: 30 mm (with cables)
Panel: High-quality milled aluminium front panel
Power Connector: Standard Eurorack +/–12V 10-pin IDC
Power Consumption: +12V: 120mA | –12V: 15mA | 5V: 0mA/not required
Storage (optional): microSD card 10/A1 or faster; FAT32 format
Physical Inputs: CV in (–5V to +5V or 0 to 10V configurable) / gate in
Physical Outputs: Audio output (Eurorack-level audio)
phybus Inputs: MIDI in 1, 2 / note gate / drum trig 1–4 / note pitch, LFO1 depth, filter cutoff
phybus Outputs: MIDI out
Maximum Instrument Cluster Size: 12 zetaSID units (6 stereo voices)
Maximum phybus Network Size: 16 modules
Maximum Total phybus Cable Length: 150 cm