SOMA Pulsar-23 (Zanzibar Blue)

Semi-modular drum machine

CAP2: 0 £1,795.00
£1,495.83 ex VAT
in stock

Organismic semi-modular drum machine and synthesizer comprising twenty-three independent modules including 4 drum voices with different architecture, four envelope generator, four looper recorders, a clock generator with dividers and a unique controlled chaos generator.

At a glance

  • Organismic semi-modular drum machine
  • Alligator clip and binding post patching interface
  • Four unique drum voices: BD, BASS, SD, and HHT
  • Unique four-channel tape looper-style sequencer
  • "Shaos" pseudo-random voltage generator with multiple step lengths
  • Digital delay and reverb effects with CV over most parameters, including DSP clock rate
  • Facilitates circuit bending using internal and external connections
  • Deep MIDI integration: MIDI learn on many drum parameters, MIDI pitch tracking on BASS voice, four assignable MIDI-to-CV converters
  • Internal or external clock with 7 unique clock divisions
  • Optional distortion on final output
  • Main output volume control

The Soma Pulsar-23 is a remarkable semi-modular drum machine and synthesizer comprising twenty-three individual modules. These modules include four unique drum voices with distinct architectures, four envelope generators, four looper recorders, a clock generator with dividers, and an intriguing controlled chaos generator.

Reimagining Analogue Drum Machines

The Soma Pulsar-23 represents a departure from conventional analogue drum machines thanks to its ingenious design. While it can be used straight out of the box without the need for patching, its true potential emerges when you explore its extensive inter and intra-connectivity. This opens up a world of sonic and rhythmic experimentation and discovery.

A Flurry of Connectivity

Rather than using the typical ⅛” and ¼” cables, the Pulsar-23 employs alligator clips and binding posts for patching connections. This unconventional approach offers greater flexibility, allowing multiple cables to connect to the same post and encouraging tactile interaction by enabling binding post connections with your fingers.

Many binding posts serve as inputs and outputs, and inputs can automatically mix multiple signals. This allows clock and modulation signals to create complex and interrelated relationships, a concept the designer aptly dubs "Organismic."

Powerful Voicings

The Pulsar-23 boasts four distinct voices, each tailored for specific applications:

BD (Bass Drum): Designed for creating analogue bass drums, this section includes Pitch and Tune controls and a Drive unit for shaping waveforms ranging from subtle to gritty industrial sounds.

BASS: This voice houses a complete subtractive mono synth section with waveform selection and a low-pass filter. It can also be configured as an additional percussion instrument with a simple switch.

SD (Snare Drum): Crafted for snare drums and clap applications, this section features a band-pass filter, a clap control, and traditional analogue snare adjustments.

HHT (High Hat): Utilizing white noise as its primary sound source and a high-pass filter for tonal control.

Each voice includes dedicated Attack and Decay controls with independent binding posts, allowing for modulation between voices. FX controls enable the assignment of each voice to the DSP Reverb and Delay section.

The master distortion module adds sound-shaping capabilities, with controls for Drive amount and a Mix knob to adjust the dry signal pass-through. It also incorporates a DSP Delay and Reverb section to add depth and space, offering various delay options and a "hall" reverb sound. These effects can be used independently or in series, with numerous modulation options via the binding posts.


Soma introduces a fresh approach to sequencing with the Pulsar-23. Instead of a traditional step sequencer, it adopts a method reminiscent of working with tape loops, enabling users to record sound events at the press of a pad, considering both start time and length.

These "loops" feature extremely high resolution, lending a human touch to your compositions. Each voice has a rhythmic quantizer to synchronize with a chosen grid. The device includes internal memory for storing four banks of four sequences for easy recall.

Robust MIDI integration allows for assigning MIDI messages to drum parameters via the Learn function or one of the four MIDI to CV binding posts. Notably, the Bass voice can be fully controlled via MIDI, enabling external keyboard performance with precise pitch tracking over five octaves.

External clocking via MIDI and an analogue clock facilitate seamless synchronization with external devices. Internal and external clocks offer seven unique clock divisions, triggering inputs, LFO synchronization, and more. Patching clock divisions between themselves allows for unique swing patterns, and clock sync modulation can be achieved by controlling the LFO frequency with an external CV.


As if the Pulsar-23's capabilities weren't sufficient, the SHAOS module adds an element of unpredictability. It incorporates a pseudo-random voltage generator using shift registers and a sample and hold circuit to generate sequences of stepped voltages. SHAOS offers three modes: 1-bit mode with two states, 2-bit mode with four states, and 3-bit mode with eight states. Users can select the length of the pseudo-random sequencer from 63, 16, or 217 modes.

A Plethora of Utilities

In addition to its core functions, the Pulsar-23 offers an array of utilities commonly found in traditional modular systems. These include four attenuators for precise parameter control, and the VCA accepts both audio and CV signals for dynamic variation. The device also provides eight 1/8” to binding post adapters and six 1/4” to binding posts, facilitating bidirectional communication with modular systems.

Supplementing these utilities are CV-controllable inverters, gate-controlled electronic switches, triggered impulse generators, and numerous other features, inviting exploration and discovery within this extraordinary machine.

Alternative Products