AMSynths AM8113 (2023–)
A Eurorack oscillator with two wave shapers built in, so it changes its waveforms as it plays.
Overview
The AM8113 is a VCO with a stable core oscillator and two dedicated wave shapers. It gives you sine, triangle, saw and square, with FM and PWM on the side. The shapers twist, fold and melt those waveforms into sounds that seem to move on their own. It sounds like something that might have crawled out of a 1978 experimental tape loop and decided to start oscillating.
Rob Keeble of AMSynths designed it. He is an engineer, a restorer and a 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 the details. The oscillator is described as "ultra stable," and that's no marketing fluff. It tracks across octaves without the wobble that plagues even some high-end analog VCOs, so it works for melodic leads or sub-bass. Where it really departs from tradition is the dual wave shaping section. It was inspired by the cult-favorite Instruo Troika (now discontinued). You get two independent wave folders/distorters that can run in series or parallel, each with its own CV control and manual knob. That lets you shape the harmonics dynamically, from glassy bell tones to snarling industrial textures, with a turn of a knob.
At 16 HP, it's not a compact module. The front panel is clean, with color-coded sections that are easy to follow in a dense rack. The wave shaping sections are laid out so you can see at a glance how your signal is being transformed. It feels substantial, like a tool built for people who spend hours tweaking. It's clearly aimed at advanced Eurorack users, but newcomers won't feel lost. Patch in a simple gate and CV, tweak the wave shapers gently, and you get warm, rich tones that wouldn't sound out of place on a 1980s synth-pop track. Push it harder and modulate the shapers with LFOs or random voltages, and you get glassy, metallic or even vocal-like textures.
Specifications
| Manufacturer | AMSynths |
| Production Years | 2023– |
| Original Price | $185 USD |
| Format | Eurorack |
| Width | 16 HP |
| Depth | 35 mm |
| Current Draw | +12V: 80 mA, -12V: 60 mA |
| Oscillator Type | Analog Voltage-Controlled Oscillator (VCO) |
| Waveforms | Sine, Triangle, Sawtooth, Square |
| Wave Shaping | Dual independent wave shapers with manual and CV control |
| Tuning Range | Over 8 octaves |
| FM Input | 1V/Oct with attenuator |
| Sync Input | Hard sync |
| Wave Shaper CV Inputs | 2 (one per shaper), normalled to attenuated LFO or external source |
| Outputs | Raw oscillator (pre-shapers), Post-shaper mix output |
| Power Connector | 2x5 pin power header (DIN 41612 compatible) |
| Panel Material | Black anodized aluminum |
| Weight | 280 g |
Key Features
A Precision Oscillator with Character
The VCO core is the serious musical part of the module. Unlike some boutique oscillators that lean into drift for "character," this one is engineered for stability without losing warmth. It tracks 1V/Oct with impressive accuracy, which suits melodic sequences and stacked patches where tuning matters. The four standard waveforms are clean but not sterile. The sawtooth has a slight softness, the sine a gentle roundness, and the square doesn't bite unless you want it to. The oscillator output can go directly to the mix output, bypassing the shapers, or through one or both shapers in series. That gives you three distinct signal paths without repatching, so you can use it as a plain VCO when needed.
Dual Wave Shapers: More Than Just Distortion
The two wave shapers are not simple overdrive circuits. They are dynamic waveform processors that handle folding, asymmetrical clipping and harmonic injection. Each shaper has its own intensity knob and CV input with attenuator. 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 for a pulsating texture while the other runs from a random voltage source. Or patch both to the same CV source and use the attenuators to set different amounts. Running the shapers in series lets you cascade them, a gentle fold first and then a sharp clip, so the sound changes a lot 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 generating complex, evolving tones from a single module. The AM8113 takes inspiration from that philosophy, but it improves on it in key ways. It's more affordable and more readily available. It also integrates the oscillator and wave shaping into a single 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, and keeps the idea of sonic exploration with a more practical, modern interface.
Historical Context
The AM8113 arrived in 2023 as part of AMSynths' broader 100M Eurorack line, a series that draws on Roland's vintage modular systems while pushing into new sonic territory. Eurorack is crowded with oscillators, some hyper-minimal and others bloated with features. The AM8113 takes a focused approach: a stable analog core plus 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. The AM8113 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 successor that makes that kind of sound design easier to get into. It also reflects a broader shift in the Eurorack world toward modules that prioritize musicality over complexity. Keeble restored vintage synths and worked with Behringer on the 2600 replica, so he knows both the quirks of classic analog circuits and the expectations of modern users.
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, it is produced in low but consistent volumes (around 500 units per year). 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 sturdy jacks and precision potentiometers that feel durable under heavy use.
For buyers, the main question 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. If you're building an analog-heavy system and want to expand your textures without adding multiple modules, it's a good 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 sought-after in a decade. If you want one, buy it new. There's no urgency to "get in early," but no reason to wait either.
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