AtomoSynth Mochika X7: analog semi-modular synth for desktop or Eurorack
AtomoSynth revives the Mochika: the X7 is an analog semi-modular with VCO, DCO, vactrol filter and 32-step sequencer, as a desktop unit or a 48 HP Eurorack module.
Peruvian small-batch maker AtomoSynth is bringing back its signature instrument with the Mochika X7, a monophonic analog semi-modular synth offered in two formats: a desktop unit and a Eurorack module. According to AtomoSynth’s official product page, the waitlist is open until October 31, 2026. The announcement was picked up on October 21 by Synth Anatomy.
Two oscillators and a vactrol filter
A semi-modular synth works on its own with a pre-wired signal path, but exposes a patch bay so you can reroute that path with cables. The Mochika X7 combines:
- an analog oscillator (VCO) with square and saw waves, plus pulse-width modulation (PWM) set by hand or by control voltage (CV);
- a digitally controlled oscillator (DCO), billed as “always in tune”, with square, saw, triangle and sine waves, plus a noise source;
- AtomoSynth’s own vactrol filter, continuously variable between low-pass and high-pass, voltage controlled;
- an ADSR envelope, an LFO morphing between pulse and triangle, and a built-in delay that accepts CV.
A vactrol pairs a tiny light source with a light-dependent resistor: the light sets the resistance, which gives the filter a slightly slow, rounded response, the trait prized in “low pass gate” percussive sounds. The four envelope stages are explained in our article on the ADSR envelope.
A 32-step sequencer at its core
Like its predecessors, the Mochika is a sequencer synth first. The X7 moves to 32 steps with four parameters per step: on/off, pitch, gate time or retrigger, and step repeat or skip. An OLED screen and eight push encoders keep every setting editable while the pattern plays.
Nine playback modes
- forward;
- reverse;
- ping-pong;
- random;
- drunk, a step-by-step random walk;
- step-trigger, for externally clocked polyrhythms;
- worm, an experimental path through the pattern;
- scrub, to sweep through the pattern;
- MIDI control, to play notes from a keyboard.
Memory holds 100 patterns. The clock syncs to an external clock, to MIDI clock (minijack input on the panel) or to USB MIDI, and a keyboard can transpose the running sequence.
Desktop or Eurorack: the two versions
| Desktop | Eurorack | |
|---|---|---|
| Format | 3D-printed case, 255 × 145 × 83 mm | 48 HP module, 25 mm deep |
| Power | external 19 V supply included | 123 mA at +12 V, 80 mA at −12 V, 30 mA at +5 V |
| Patch bay | 18 points: 9 inputs, 9 outputs (CV, gate, clock, FM, PWM, filter, delay, LFO, envelope) | |
| Waitlist price | US$399 | US$349 |
| Regular price | US$449 | US$389 |
HP (horizontal pitch) is the Eurorack width unit, 5.08 mm: 48 HP takes up a little over a quarter of a common 168 HP case row. Before racking it, check your power supply’s headroom on all three rails; our guide to the Eurorack format and your first case walks through that budget.
AtomoSynth’s official sound demo:
Who it’s for, what it costs, what it competes with
Who it’s for. Players who want a standalone bass or sequence voice with a generous sequencer, and who may plug it into a modular system later. The Eurorack version targets people who already own a case and want a complete voice, sequencer included, in 48 HP. Not for anyone after a polysynth or a keyboard: the Mochika X7 plays one note at a time and has no keys.
What it costs. AtomoSynth lists US$449 for the desktop and US$389 for the Eurorack module, cut to US$399 and US$349 for waitlist sign-ups until October 31, 2026. Worldwide DHL Express shipping from Lima is free. Euro pricing, import duties and the shipping date have not been announced. Units are hand-assembled and calibrated in small batches, so availability will depend on production.
What it competes with. At this price, the reference semi-modular is the Behringer Crave: one VCO, a ladder-style filter, a 32-step sequencer and a 32-point patch bay, for far less money. The pricier Make Noise 0-Coast plays a different game, “West Coast” synthesis with no step sequencer. The Mochika X7 stands out with two oscillators (one of them a stable DCO), a vactrol filter, a CV-controllable delay and nine playback modes; it gives up the Crave’s bigger patch bay and comes with the uncertain lead times of a hand-built product. Other rack voices and sequencers are covered in our Eurorack Modules and Sequencers & Control sections, including the Squarp Core.
Official page and waitlist: Mochika X7 on atomosynth.co.