TL;DR: Vostok Instruments, the Barcelona-based wizards of voltage, have unveiled the Halo—a compact 10HP quad LFO module that cranks out up to 16 simultaneous modulation signals thanks to an integrated logic section. With full CV control over each of its four analog cores and boolean operations like AND, OR, XOR, and MIX, this isn’t your grandmother’s modulation source; it’s a tiny brain for chaotic, evolving patches. Available now for $229/€199.
- Four CV-controlled analog LFOs with triangle and square outputs per channel, plus two frequency ranges (low LFO to high HFO/audio rate).
- Dedicated logic section adds eight extra outputs per channel pair using AND, OR, XOR, and MIX—yielding up to 16 simultaneous signals from a 10HP module.
- No menus, no switching: every control is a knob or jack, making it as hands-on as a classic analog module should be.
- Priced at $229/€199, available now from Vostok Instruments.
- Targets modular users craving dense, evolving modulation without sacrificing precious rack space.
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The Halo Effect
Let’s be honest: a quad LFO module isn’t exactly headline news in Eurorack. We’ve seen them before, and they’re typically as thrilling as watching paint dry—reliable, predictable, and perfectly adequate. But Vostok Instruments, the Barcelona-based outfit that gave us the excellent Fujin and Cerberus, has decided to inject some chaos into the formula with their new Halo module.
Unveiled at Superbooth 2026, Halo is a compact 10HP module that promises “a large amount of modulation in just 10HP.” That’s marketing speak, of course, but the specs back it up: four CV-controlled analog LFOs, each with triangle and square outputs, plus a dedicated logic section that generates up to eight additional signals from channel pairs. Total: 16 simultaneous modulation signals. That’s enough to make even the most jaded patcher sit up and take notice.
The module’s design is refreshingly old-school: no menus, no hidden submenus, no screen to squint at. Every function has a dedicated knob or jack. It’s the kind of hands-on interface that makes you want to wiggle, not scroll. At $229/€199, it’s priced competitively for a module with this much juice.
Analog Core, Digital Mind
Each of Halo’s four LFO channels is built around an analog core with full CV control over frequency. Vostok Instruments says the frequency ranges are “finely tuned to cover most applications,” which in practice means you can use it as a traditional LFO for slow sweeps or crank it up to audio rate for an HFO (high-frequency oscillator). That’s useful for FM, clocking, or even basic sound generation in a pinch.
The waveforms are basic—triangle and square—but that’s by design. Vostok knows that the real magic happens in the logic section, not in the raw outputs. Still, having both waveforms available simultaneously on dedicated jacks is a quality-of-life feature that many quad LFOs overlook. You can send the triangle to modulate a filter while the square triggers a sequencer, all from the same channel.
CV control is the star here. Each channel’s frequency can be modulated by external voltage, which means you can create complex, interdependent modulation networks without a single cable touching a knob. It’s the kind of flexibility that rewards experimentation—and frustration, because you’ll inevitably spend an afternoon chasing a perfect patch that collapses as soon as you unplug the wrong cable.
The Logic Twist
Here’s where Halo stops being a “nice, well-designed LFO” and becomes something genuinely interesting. The logic section takes pairs of LFO channels and applies analog boolean operations—AND, OR, XOR, and MIX—to create new waveforms. That’s four additional outputs per pair, for a total of eight extra signals from the logic section alone.
What does this sound like? Imagine two LFOs slowly phasing in and out of sync. Feed them into an AND gate, and you get a signal that only goes high when both are high—a rhythmic, stuttering pulse that’s perfect for triggering envelopes or syncing drum modules. XOR gives you a signal that flips state when the two inputs differ, creating chaotic, unpredictable patterns. MIX is simple voltage addition, which can produce complex, evolving shapes that neither LFO could create alone.
This isn’t new tech—boolean logic has been in modular since the ’60s—but packaging it with a quad LFO in 10HP is clever. It turns a workhorse modulation source into a generative engine. You can patch the logic outputs back into the LFOs’ CV inputs and create feedback loops that evolve over minutes, not seconds. It’s the kind of module that rewards patience and a willingness to let the patch breathe.
Market Context and Verdict
Vostok Instruments isn’t a household name, but they’ve built a reputation for thoughtful, affordable modules that punch above their HP. Halo fits that mold. At 10HP, it’s narrower than many quad LFOs (the classic Doepfer A-143-3 is 16HP, for example) and offers more modulation outputs than most. The logic section is the clear differentiator—without it, this would be a competent but unremarkable module.
Who is this for? Anyone building a small system who wants dense modulation without sacrificing space. Also, patchers who love generative or chaotic patches but don’t want to dedicate a whole rack to random sources. And, of course, the kind of person who enjoys explaining boolean logic to friends at parties. (We see you.)
At $229/€199, it’s reasonably priced for a module of this complexity. It’s not cheap, but it’s cheaper than buying a quad LFO plus a separate logic module. If you’re on a budget and need modulation, this is a strong contender. If you already have a quad LFO, you might still want this for the logic alone. Either way, Vostok Instruments has delivered a module that’s more than the sum of its parts—and that’s exactly what we want to see.
Frequently Asked Questions
Can Halo be used as an audio oscillator?
Yes. The high frequency range covers audio rates, so you can use each channel as a basic VCO. However, the waveforms are limited to triangle and square, and there’s no pitch tracking via 1V/oct—so don’t expect to play melodies. It’s more useful for FM, clocking, or noise textures.
Do I need to patch all four LFOs to use the logic section?
No. The logic section operates on pairs of channels (1+2, 3+4), but you can use just one channel per pair if you want. The unused channel’s output will simply be static, so the logic outputs will reflect only the active channel’s signal.
How does Halo compare to other quad LFOs with logic, like the Xaoc Devices Batumi?
Batumi is a classic, but it’s digital and requires menu diving for some features. Halo is fully analog with no menus, which some users prefer for immediacy. Batumi offers more wave shapes and a larger feature set, but Halo’s logic section is more straightforward and hands-on. Price-wise, they’re in the same ballpark.
Now if you’ll excuse me, I need to patch four LFOs into a logic gate and see if I can make my coffee maker modulate itself. It’s either genius or a fire hazard—I’ll let you know after the next Superbooth.