AMSynths AM8113 (2023–)

A Eurorack oscillator that doesn’t just generate waveforms—it reinvents them on the fly.

Overview

Plug in the AM8113 and you’re not just adding another VCO to your rack—you’re installing a waveform alchemist. This isn’t a module that settles for sine, triangle, saw, and square with a little FM or PWM on the side. It starts there, sure, with a stable core oscillator that locks in pitch like it’s bolted to bedrock, but then it hands you two dedicated wave shapers that let you twist, fold, and melt those waveforms into sounds that feel like they’re breathing on their own. It’s the kind of module that makes you stop patching for a second and just listen, because what’s coming out isn’t just another sawtooth with resonance—it’s something that sounds like it’s alive, something that might have crawled out of a 1978 experimental tape loop and decided to start oscillating.

Designed by Rob Keeble of AMSynths—engineer, restorer, and former Behringer collaborator—the AM8113 is part of the 100M Eurorack line, a series inspired by classic Roland modular systems but built with modern precision and a touch of British eccentricity. Keeble’s background in restoring vintage gear and reverse-engineering classic circuits shows in every detail: the AM8113 doesn’t just emulate old-school behavior, it improves on it. The oscillator is described as “ultra stable,” and that’s no marketing fluff. It’s built to track across octaves without the wobble that plagues even some high-end analog VCOs, making it equally at home in melodic leads or sub-bass duties. But where it really diverges from tradition is in its dual wave shaping section. Inspired by the cult-favorite Instruo Troika (now discontinued), the AM8113 gives you two independent wave folders/distorters that can be applied in series or parallel, each with its own CV control and manual knob. This means you’re not just adding harmonics—you’re sculpting them dynamically, creating evolving timbres that shift from glassy bell tones to snarling industrial textures with a turn of a knob.

At 16 HP, it’s not a compact module, but it earns every millimeter. The front panel is clean but purposeful, with color-coded sections that make it easy to navigate even in a dense rack. Inputs and outputs are thoughtfully placed, and the wave shaping sections are laid out so you can see at a glance how your signal is being transformed. It’s not flashy, but it feels substantial—like a tool built for people who spend hours tweaking, not just browsing presets. And while it’s clearly aimed at advanced Eurorack users, it’s not so esoteric that newcomers will feel lost. Patch in a simple gate and CV, tweak the wave shapers gently, and you’ve got warm, rich tones that wouldn’t sound out of place on a 1980s synth-pop track. Push it harder, modulate the shapers with LFOs or random voltages, and you’re in experimental territory—glassy, metallic, or even vocal-like textures that feel like they’re on the edge of recognition.

Specifications

Key Features

A Precision Oscillator with Character

The AM8113’s VCO core is where the module earns its keep as a serious musical tool. Unlike some boutique oscillators that lean into drift for “character,” this one is engineered for stability without sacrificing warmth. It tracks 1V/Oct with impressive accuracy, making it reliable for melodic sequences or stacked patches where tuning integrity matters. The four standard waveforms are clean but not sterile—there’s a slight softness to the sawtooth, a gentle roundness to the sine, and a square wave that doesn’t bite unless you want it to. But the real magic begins the moment you route that signal into the wave shaping section. The oscillator output can be sent directly to the mix output (bypassing the shapers), or routed through one or both shapers in series, giving you three distinct signal paths without needing to repatch. This flexibility means you can use the AM8113 as a straightforward VCO when needed, or unleash its full potential when you’re ready to explore.

Dual Wave Shapers: More Than Just Distortion

The two wave shapers are not simple overdrive circuits—they’re dynamic waveform processors capable of folding, asymmetrical clipping, and harmonic injection. Each shaper has its own intensity knob and CV input with attenuator, allowing for precise control over how much transformation is applied. At low settings, they add subtle warmth or gentle saturation; crank them up, and you get full-on wavefolding with the kind of complex harmonic content usually found in digital synths or granular processors. Because they’re analog, the transitions are smooth and organic, never harsh or digital-sounding. You can modulate one shaper with an LFO to create a pulsating texture while using the other with a random voltage source for unpredictability. Or patch both to the same CV source and use the attenuators to create layered, evolving timbres. The ability to route the shapers in series means you can cascade their effects—first a gentle fold, then a sharp clip—resulting in sounds that evolve dramatically across a single note.

Inspired by the Instruo Troika, But More Accessible

The Instruo Troika, a now-discontinued module, became something of a legend for its ability to generate complex, evolving tones from a single module. The AM8113 clearly takes inspiration from that philosophy, but it improves on it in key ways. For one, it’s more affordable and more readily available. For another, it integrates the oscillator and wave shaping into a single, streamlined unit without sacrificing patchability. The Troika required external VCOs and careful calibration; the AM8113 is self-contained, stable, and ready to go. It doesn’t try to replicate the Troika exactly—instead, it captures its spirit of sonic exploration while offering a more practical, modern interface. It’s the kind of module that feels like a collaboration between a mad scientist and a seasoned studio engineer: wild in concept, but rock-solid in execution.

Historical Context

The AM8113 arrived in 2023 as part of AMSynths’ broader 100M Eurorack line, a series that pays homage to Roland’s vintage modular systems while pushing into new sonic territory. At a time when Eurorack is crowded with oscillators—some hyper-minimal, others bloated with features—the AM8113 stands out by offering a focused but powerful concept: take a stable analog core and give it transformative sound-shaping tools usually found in separate modules. It’s a response to the trend of “do everything” oscillators that end up being jacks-of-all-trades and masters of none. Instead, the AM8113 does one thing exceptionally well: it generates and mutates waveforms in real time with analog warmth and precision.

Its spiritual predecessor, the Instruo Troika, was beloved but notoriously difficult to obtain and expensive on the used market. The AM8113 fills that gap—not as a clone, but as a worthy successor that democratizes that kind of sound design. It also reflects a broader shift in the Eurorack world toward modules that prioritize musicality over complexity. Keeble’s background in restoring vintage synths and working with Behringer on the 2600 replica gives him a rare perspective: he understands both the quirks of classic analog circuits and the expectations of modern users. The AM8113 feels like the work of someone who’s spent decades listening to oscillators fail, drift, and surprise—and who finally built one that does exactly what he wanted.

Collectibility & Value

As of 2026, the AM8113 is still in production and readily available directly from AMSynths, with an MSRP of $185. It hasn’t yet entered the vintage market in any meaningful way, but given Keeble’s reputation and the module’s unique feature set, it’s likely to hold its value well. Unlike limited-run boutique modules that inflate on the secondary market, the AM8113 is produced in low but consistent volumes (around 500 units per year), making it accessible without being common. There are no known failure points or design flaws reported by owners—no cold solder joints, no tuning instability, no power issues. The build quality is solid, with robust jacks and precision potentiometers that feel durable under heavy use.

For buyers, the main consideration isn’t reliability but relevance: do you need a module that specializes in waveform mutation? If your rack is full of digital oscillators or complex wavetable modules, the AM8113 might feel redundant. But if you’re building an analog-heavy system and want to expand your textural palette without adding multiple modules, it’s a compelling choice. Used units, when they appear, trade close to retail—typically $150–$180 depending on condition. There’s no indication it will be discontinued soon, but given its niche appeal and the fate of similar modules (like the Troika), it wouldn’t be surprising to see it become a sought-after item in a decade. For now, the best advice is simple: if you want one, buy it new. There’s no urgency to “get in early,” but there’s also no reason to wait.

eBay Listings

As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.

Related Models

• AMSynths AM-CP1
• AMSynths AM-CP3
• AMSynths AM1005
• AMSynths AM1006
• AMSynths AM1013
• 4ms Ping
• ADC 27
• 2hp LPG V2
• ALM Busy Circuits MS-014
• ALM AXON-2